Handheld two-way radios for preppers and other curious folks(lcamtuf.coredump.cx)
lcamtuf.coredump.cx
Handheld two-way radios for preppers and other curious folks
https://lcamtuf.coredump.cx/prep/handheld.html
152 comments
This is an area I've been interested in learning more about for a while (not for prepping, just learning). Are there any good resources for getting started with ham radio? I've been looking for a guide that can explain the math and physics behind it along with the electronics.
http://www.arrl.org/shop/Ham-Radio-License-Manual/
This is really all you need to get started. I was 14 when I first got my license - I used an earlier iteration of this book to self study. It’s really straightforward. Feel free to email with any questions! Always glad to help people get started in ham radio.
This is really all you need to get started. I was 14 when I first got my license - I used an earlier iteration of this book to self study. It’s really straightforward. Feel free to email with any questions! Always glad to help people get started in ham radio.
I will additionally suggest the "ARRL Handbook" (there's a new edition every year - mine was 2001 and I guess there is no need to get the latest one), from which I learned everything about electronics, antennas and radio propagation during my high school years. It not only enabled me to build and experiment with ham radio transceivers, but also gave me quite a head start into my university studies of EE.
ARRL Handbook is great, but I would suggest picking it up after someone has their license. Personally, I found it really frustrating to have a gigantic book full of interesting things that I wasn’t legally allowed to do - it was a much better book after I had my license :)
Ordered! Thanks so much for the suggestion!
The ARRL publishes books that would be of interest.
> I've been looking for a guide that can explain the math and physics behind it along with the electronics.
Interesting. I expect that if the physics in one of their books about, for example, antennas is not oriented towards math and physics enough for your liking, you’ll at least get some direction as to what part of a real physics textbook you need to study.
> I've been looking for a guide that can explain the math and physics behind it along with the electronics.
Interesting. I expect that if the physics in one of their books about, for example, antennas is not oriented towards math and physics enough for your liking, you’ll at least get some direction as to what part of a real physics textbook you need to study.
Interesting, but complicated. It would be easier to just get your amateur radio license and build out from there. Granted you’re getting a license from the FCC to operate, which might upset certain preppers, but in terms of cost and availability of equipment, the amateur radio route is much more direct and cost-effective.
What in the link are you responding to?
Isn’t a handheld radio an “amateur” radio? Or is there a nuanced distinction between the two?
It also does seem odd that this requires licensing. Why is that? And if you were not licensed how would they even identify you or track you down?
It also does seem odd that this requires licensing. Why is that? And if you were not licensed how would they even identify you or track you down?
"Amateur radio" or "ham radio" is a class of noncommercial radio licensees in the US and many other countries. There are reserved radio bands, various rights and obligations, and perhaps most importantly a large community of people using similar technology. Think of it as the open-source version of CB radio.
The radio might be handheld or vehicle-mounted or a fixed installation occupying hundreds of feet on a side. (Conversely just because something is handheld doesn't make it amateur: your cell phone is a commercial radio service; walkie-talkies and FRS and wifi are unlicensed services; etc. Type-approval is different from licensing.)
The radio might be handheld or vehicle-mounted or a fixed installation occupying hundreds of feet on a side. (Conversely just because something is handheld doesn't make it amateur: your cell phone is a commercial radio service; walkie-talkies and FRS and wifi are unlicensed services; etc. Type-approval is different from licensing.)
Q: "And if you were not licensed how would they even identify you or track you down?"
A: Ham radio uses a frequency band plan that everyone agrees to adhere to, so if someone shows up on those frequencies who doesn't belong, we will notice.
Hams are also required to broadcast their FCC allocated "call sign" about every 10 minutes, or when starting and ending a transmission, if you're not doing that, then licensed Hams will notice.
If you think you're being "clever" and make up a fake call-sign, we will notice, we know who the regulars on the Ham frequencies are in our geographic areas.
If you're producing "harmful interference", i.e. illegally broadcasting on a licensed Amateur Radio Band, then some of "us" Hams will get together and Track your signal, via triangulation, and eventually we Will find your transmitting location.
Then we notify the FCC, and eventually... they will contact you, and you Will stop, or face legal consequences.
A lot of Hams enjoy tracking down hidden transmitters, we even set up "games" to practice doing just that, we call it a "Hare & Hound" practice.
I'm quite good at tracking down harmful interference on the VHF Ham bands.
Ham radio has a lot of places to explore, but do avoid the H/F bands, it's full of "rag chewers", and you'll want to poke out your eardrums if you listen to them.
73, KE6---
A: Ham radio uses a frequency band plan that everyone agrees to adhere to, so if someone shows up on those frequencies who doesn't belong, we will notice.
Hams are also required to broadcast their FCC allocated "call sign" about every 10 minutes, or when starting and ending a transmission, if you're not doing that, then licensed Hams will notice.
If you think you're being "clever" and make up a fake call-sign, we will notice, we know who the regulars on the Ham frequencies are in our geographic areas.
If you're producing "harmful interference", i.e. illegally broadcasting on a licensed Amateur Radio Band, then some of "us" Hams will get together and Track your signal, via triangulation, and eventually we Will find your transmitting location.
Then we notify the FCC, and eventually... they will contact you, and you Will stop, or face legal consequences.
A lot of Hams enjoy tracking down hidden transmitters, we even set up "games" to practice doing just that, we call it a "Hare & Hound" practice.
I'm quite good at tracking down harmful interference on the VHF Ham bands.
Ham radio has a lot of places to explore, but do avoid the H/F bands, it's full of "rag chewers", and you'll want to poke out your eardrums if you listen to them.
73, KE6---
To be honest I hear a lot more ragchewing on the local repeaters than on HF. On HF it's just people trading 5/9s and signing off for the next contact (and as I find contesting really boring I stay away from HF for that reason :) ). I also don't understand why HF operators always say 5/9 when the signal is clearly nowhere near that good.
Here in N. California 2 Meters is king, and we have local and linked repeaters, but mostly they are quiet save for the weekly nets, and I'm fine with that.
Since we reside in a rural and coastal/mountainous County, what usually happens is Hams will set up QSO's on "open" frequencies and chat there to keep the repeaters clear for emergency use.
So they either call on 146.520 simplex or jump on a repeater and connect, then go to their other frequency to chat.
Aside from not have many privileges on HF, I avoid it, too much Noise as far as I'm concerned, and I mean the Hams.
Since we reside in a rural and coastal/mountainous County, what usually happens is Hams will set up QSO's on "open" frequencies and chat there to keep the repeaters clear for emergency use.
So they either call on 146.520 simplex or jump on a repeater and connect, then go to their other frequency to chat.
Aside from not have many privileges on HF, I avoid it, too much Noise as far as I'm concerned, and I mean the Hams.
> A lot of Hams enjoy tracking down hidden transmitters, we even set up "games" to practice doing just that, we call it a "Hare & Hound" practice.
Hams really seem to enjoy being snitches!
I'll keep playing with my Baofangs and their aftermarket antennas! Also I'll wait until HAM dies out as a old white men hobby, and the frequency band are repurposed to a better use that allows anonymity and encryption - or I'll stay on public solutions like WIFI/LoraWAN!
Hams really seem to enjoy being snitches!
I'll keep playing with my Baofangs and their aftermarket antennas! Also I'll wait until HAM dies out as a old white men hobby, and the frequency band are repurposed to a better use that allows anonymity and encryption - or I'll stay on public solutions like WIFI/LoraWAN!
‘Amateur’ in this context means ‘requires a licence to operate but at lower tier of licence’. So no most handheld radios aren’t ‘amateur’.
Answer 9 gives some info on which radios require a license to operate.
Direction finding/fox hunting is a way to get caught. In reality, if you’re not causing trouble, you’re never going to get looked for, of course.
Direction finding/fox hunting is a way to get caught. In reality, if you’re not causing trouble, you’re never going to get looked for, of course.
Where I used to live no one plowed the road so every time it snowed my dad to drive his bobcat (he's one of those tech workers that owns machinery "for fun") down an hilly icy road with huge ravines on each side and no cell signal. After we both got our HAM license he would carry one of these cheap 2m handhelds with him and could check in with us every so many minutes. They work way better than FRS radios (much more power, longer antennas, more bandwidth (FRS is almost unintelligible by comparison.))
Some people feel like HAM has no practical use outside of emergencies but there are definitely places where the owners of the spectrum have failed to build the infrastructure needed to use it.
Some people feel like HAM has no practical use outside of emergencies but there are definitely places where the owners of the spectrum have failed to build the infrastructure needed to use it.
HAM is still a very necessary tool for keeping in contact in the mountains and such. When I was younger I did some SCCA rally events. Those events would be impossible without the volunteer HAM operators that show up and set up temporary relays on a couple of the biggest foothills in the race area. Cell coverage is just too spotty, and satcom stuff is just too expensive. My understanding is that search and rescue uses the same approach for the same reasons.
> HAM is still a very necessary tool for keeping in contact in the mountains and such.
Depends on the location. The company I work for produces a mountain-top repeater[0] series. Hundreds of them are distributed throughout the Rocky Mountains in British Columbia, providing an expansive coverage for handheld devices.
If you're curious about what an installation site looks like atop a mountain, check out pages 38-39 in an older product guide[1].
[0]: https://codancomms.com/products/mt-4e-series
[1]: https://www.yumpu.com/en/document/read/38724760/land-mobile-...
Depends on the location. The company I work for produces a mountain-top repeater[0] series. Hundreds of them are distributed throughout the Rocky Mountains in British Columbia, providing an expansive coverage for handheld devices.
If you're curious about what an installation site looks like atop a mountain, check out pages 38-39 in an older product guide[1].
[0]: https://codancomms.com/products/mt-4e-series
[1]: https://www.yumpu.com/en/document/read/38724760/land-mobile-...
NSFW WARNING: The link [1] above (yumpu.com) is showing an ad with topless women over the document.
Oof! Thank you for pointing that out. I'll check into why this file isn't on our public CDN and why a spam site has our document. Meanwhile, a few safer links:
* https://caraham.org/resources/Documents/Learning%20Conferenc... - page 37 in the PDF (29 in the document) shows various radio towers atop of mountains
* https://cdn.codancomms.com/general-downloads/Products/User-G... - overview of radio communications fundamentals
* https://caraham.org/resources/Documents/Learning%20Conferenc... - page 37 in the PDF (29 in the document) shows various radio towers atop of mountains
* https://cdn.codancomms.com/general-downloads/Products/User-G... - overview of radio communications fundamentals
Not when I looked :-(
:-)
Perhaps you should install UBlock origin.
:-)
Perhaps you should install UBlock origin.
[deleted]
This is cool!
Thanks for sharing!
"Some people feel like HAM has no practical use outside of emergencies but there are definitely places where the owners of the spectrum have failed to build the infrastructure needed to use it."
I keep reading about all of these very interesting protocols for texting over HAM radio ... and a lot of them seem very promising.
My next step is to survey the landscape of devices that could be used to actually send and receive these text messages ... and there are none.
Am I mistaken ? Does there exist a handheld radio that can be used to send and receive text messages over one of these HAM protocols ?
I keep reading about all of these very interesting protocols for texting over HAM radio ... and a lot of them seem very promising.
My next step is to survey the landscape of devices that could be used to actually send and receive these text messages ... and there are none.
Am I mistaken ? Does there exist a handheld radio that can be used to send and receive text messages over one of these HAM protocols ?
Seriously! I keep feeling the same lack. I want something in the form factor of an early Blackberry or something.
I'd love it to have three radio decks: One ham transceiver, so I can use direct APRS-or-whatever with other nearby nodes or digipeaters, though I know the antenna will suck. One Bluetooth, so it can act as the QWERTY UI for a more powerful radio that lacks a decent keyboard (or as a generic peripheral for other projects). And one Part-15, perhaps LoRa or something, so it can also operate in an unlicensed mode with Meshtastic or something as the protocol over longer range than Bluetooth.
I'm pretty sure I could design the hardware, both the electronics and the enclosure, but I can't code my way out of a wet paper bag, so that's sort of a non-starter.
The bigger question question is, why doesn't this exist yet? Are there HTs with native Bluetooth so the texting UI could be implemented as a phone app? I know there are some with Bluetooth for other functions but I'm not clear on whether they can act as a KISS TNC over SPP.
If so, that would be a great interface to standardize on, implement the phone app for testing, then turn it into a physical gizmo to enjoy longer battery life and cheaper/rugged hardware. Then as a next step, bring the Part-97 hardware into the gizmo.
I'd love it to have three radio decks: One ham transceiver, so I can use direct APRS-or-whatever with other nearby nodes or digipeaters, though I know the antenna will suck. One Bluetooth, so it can act as the QWERTY UI for a more powerful radio that lacks a decent keyboard (or as a generic peripheral for other projects). And one Part-15, perhaps LoRa or something, so it can also operate in an unlicensed mode with Meshtastic or something as the protocol over longer range than Bluetooth.
I'm pretty sure I could design the hardware, both the electronics and the enclosure, but I can't code my way out of a wet paper bag, so that's sort of a non-starter.
The bigger question question is, why doesn't this exist yet? Are there HTs with native Bluetooth so the texting UI could be implemented as a phone app? I know there are some with Bluetooth for other functions but I'm not clear on whether they can act as a KISS TNC over SPP.
If so, that would be a great interface to standardize on, implement the phone app for testing, then turn it into a physical gizmo to enjoy longer battery life and cheaper/rugged hardware. Then as a next step, bring the Part-97 hardware into the gizmo.
Check out the M17 project, they seem to be making inroads in that area.
https://m17project.org/
Mobilink tncs are really nice but you're still limited by APRS.
https://m17project.org/
Mobilink tncs are really nice but you're still limited by APRS.
M17 sounds cool, but as near as I can tell you cant just buy some hardware for it. Its still a plug your PC into a generic radio technology (which is fine, but some people just want to spend the money to get a working all in one solution).
I played with Meshtastic and was disappointed with range. I did not really expect miracles given LoRa's limited power, but 50 yards with direct line of sight was underwhelming.
That's hardly the protocol's fault though.
When I discovered Meshtastic, I already had some of the Heltec modules around, which are reputed to have the worst RF performance. I tried anyway, and indeed, I had to equip some truly silly antennas to get even a mile of range. (18dBi yagi in my living room, pointed at a parking structure downtown, was able to talk to another node on top of the structure with a 6dBi omni. Just barely.)
I've been pursuing other projects since then, but a quick skim of the meshtastic forum suggests that there are some much better-performing RF modules now. I'll play with those soon enough...
And anyway, there are encodings other than the patent-encumbered LoRa worth considering, too. (The LoRa folks just did a stellar job capturing mindshare lately.) Really, a feature-set identical to the original IM-ME, but with an option to use ham radios to extend the range, is what I want.
When I discovered Meshtastic, I already had some of the Heltec modules around, which are reputed to have the worst RF performance. I tried anyway, and indeed, I had to equip some truly silly antennas to get even a mile of range. (18dBi yagi in my living room, pointed at a parking structure downtown, was able to talk to another node on top of the structure with a 6dBi omni. Just barely.)
I've been pursuing other projects since then, but a quick skim of the meshtastic forum suggests that there are some much better-performing RF modules now. I'll play with those soon enough...
And anyway, there are encodings other than the patent-encumbered LoRa worth considering, too. (The LoRa folks just did a stellar job capturing mindshare lately.) Really, a feature-set identical to the original IM-ME, but with an option to use ham radios to extend the range, is what I want.
I used TTGO modules with omnidirectional antennas.
By now we have very efficient modulation like FT8 and LDPC error-correcting codes, so I think it should be possible to do much better, even within Part 15 limitations.
By now we have very efficient modulation like FT8 and LDPC error-correcting codes, so I think it should be possible to do much better, even within Part 15 limitations.
Agreed, but I'm not aware of anyone trying to build those into handheld communicators.
I would love to see that Incorporated into a 2 M transceiver because I'm not aware of any commercial Ham radios that natively send text (yet).
But during emergency nets some of us use Fldigi (short for Fast light digital), a free and open-source program which allows an ordinary computer's sound card to be used as a simple two-way data modem.
The software is mostly used by amateur radio operators who connect the microphone and headphone connections of an amateur radio SSB transceiver or an FM two way radio to the computer's headphone and microphone connections, respectively.
https://en.wikipedia.org/wiki/Fldigi
It can be difficult for some to get set up and properly configured, but once it's working, it will transmit text messages without major errors under the noise floor, i.e. can barely hear it because of all the white noise.
It does cause complaint's when used on voice simplex frequencies and repeaters.
It sounds worse than packet radio https://en.wikipedia.org/wiki/Packet_radio which I kind of like hearing.
But during emergency nets some of us use Fldigi (short for Fast light digital), a free and open-source program which allows an ordinary computer's sound card to be used as a simple two-way data modem.
The software is mostly used by amateur radio operators who connect the microphone and headphone connections of an amateur radio SSB transceiver or an FM two way radio to the computer's headphone and microphone connections, respectively.
https://en.wikipedia.org/wiki/Fldigi
It can be difficult for some to get set up and properly configured, but once it's working, it will transmit text messages without major errors under the noise floor, i.e. can barely hear it because of all the white noise.
It does cause complaint's when used on voice simplex frequencies and repeaters.
It sounds worse than packet radio https://en.wikipedia.org/wiki/Packet_radio which I kind of like hearing.
APRS / SMSGTE: https://smsgte.org/
Thanks, I'm well aware of APRS, it's a neat technology, I know many Hams who use it, but don't feel the need.
I travel long distances on my motorbike as often as I can, I go naked, no phone, no eletronics except my 2M transeiver and point and shoot camera.
I travel long distances on my motorbike as often as I can, I go naked, no phone, no eletronics except my 2M transeiver and point and shoot camera.
Well, you're asking for amateur radios which natively send text, and there are many amateur radios which natively support APRS. APRS can send text. Hitting an I-GATE, they can send and receive SMS. So from my Kenwood TH-D74A I can natively send and receive text. There are many radios out there which natively support APRS, which means they natively support text. Many other radios can natively support this text functionality. It seems like its the thing you were requesting in your earlier comment, but you're brushing it away. What is APRS lacking in terms of text transmission?
https://preppcomm.com/
Company local to me makes these. I haven't tried one but it looks interesting.
I did some rework on a couple of their prototype boards.
edit: TLDR; it is a morse code transceiver
Company local to me makes these. I haven't tried one but it looks interesting.
I did some rework on a couple of their prototype boards.
edit: TLDR; it is a morse code transceiver
Sure, a Kenwood TH-D74A can send messages over APRS. The older ‘72’ could too. So can a Yaesu FT-1DR. Plenty of cheaper devices can too. Now if you look at those, you’ll find some odd ideas—features like a built in 320x240 camera. They’re an odd mix of very young and very old tech ideas, because they’re the products of small engineering teams and weird budgets.
I would not recommend analog APRS for reliable text communication, or anything except periodic, unidirectional (radio to internet), fire and forget position/status/etc reports (for which APRS often can't be beat due its to extensive coverage in many regions).
Instead, try DMR. Does voice, text and also digital APRS. Motorola and Hytera are probably the leading manufacturers of radios. Works direct and via DMR repeaters. If you have a repeater close by, you get worldwide radio to radio / talkgroup calling.
Unfortunately both modes have many, many annoying quirks/constraints.
Instead, try DMR. Does voice, text and also digital APRS. Motorola and Hytera are probably the leading manufacturers of radios. Works direct and via DMR repeaters. If you have a repeater close by, you get worldwide radio to radio / talkgroup calling.
Unfortunately both modes have many, many annoying quirks/constraints.
"Instead, try DMR. Does voice, text and also digital APRS."
OK, but how do I physically key in the text message from the handheld device ? Is it the old-fashioned pre-qwerty method of pressing a number once or twice or thrice to get the desired alpha character ?
Perhaps my initial question was not clear: In the most primitive of ways, how do I actually key in a text message on the handheld device ?
OK, but how do I physically key in the text message from the handheld device ? Is it the old-fashioned pre-qwerty method of pressing a number once or twice or thrice to get the desired alpha character ?
Perhaps my initial question was not clear: In the most primitive of ways, how do I actually key in a text message on the handheld device ?
Oh. Yes, those DMR radios have T9 keypads. Its awful, but the best we have.
For analog APRS, which as I said has questionable reliability (for many reasons), you can use a smartphone app (like APRSDroid) and either an audio cable to the radio (the smartphone acts as a software TNC that will generate the signal, the radio modulates it on the carrier), or a separate hardware TNC which connects to the radio via audio, but to your phone in another way such as bluetooth low energy (like Mobilinkd TNC3). Then you can type on your phone. (In that case, the protocol is still done by the phone, the TNC only generates the signal, the radio modulates it. Which is annoying due to power consumption.) (Analog APRS support which is built in to radios is usually position report only, not messaging.)
For analog APRS, which as I said has questionable reliability (for many reasons), you can use a smartphone app (like APRSDroid) and either an audio cable to the radio (the smartphone acts as a software TNC that will generate the signal, the radio modulates it on the carrier), or a separate hardware TNC which connects to the radio via audio, but to your phone in another way such as bluetooth low energy (like Mobilinkd TNC3). Then you can type on your phone. (In that case, the protocol is still done by the phone, the TNC only generates the signal, the radio modulates it. Which is annoying due to power consumption.) (Analog APRS support which is built in to radios is usually position report only, not messaging.)
Sadly, all those Kenwoods are now discontinued.
AnyTone, TYT, Radioddity, Baofeng and other cheap Chinese radios ate Kenwood's lunch. For example, AnyTone D878UV has built-in GPS and can send APRS messages.
The AKM factory fire is a more likely the cause for the D74's discontinuation than competition.
DMR radios support SMS. But without a keyboard or touch screen it's not particularly user friendly. And you can't use encryption.
Morse code?
I was reading through waiting for someone to say that. Morse is intelligible with significant background noise, has a tiny bandwidth, requires very low power and is pretty popular. However it is not that easy to learn....I certainly failed!
If it is that good surely a simple program could be used to generate Morse from ordinary text and text from Morse or is there some non-technical reason why Morse code has to be generated by hand?
Most Morse is not generated by hand. The human ear tends to be much better at decoding it under sub-optimal conditions though.
Linked this above...but relevant here.
https://preppcomm.com/
https://preppcomm.com/
lots of people are using a PC or phone running the software and either connecting that to a radio via the line-out port or using an SDR.
Are we done caring about the restriction on encryption? I'm down.
No, we aren't and we like it the way it is.
The last thing ham radio needs is corporations just taking our bands, or ham radio getting banned in unstable countries over espionage concerns.
If you want encryption, use a cellphone, LoRaWAN etc.
The last thing ham radio needs is corporations just taking our bands, or ham radio getting banned in unstable countries over espionage concerns.
If you want encryption, use a cellphone, LoRaWAN etc.
I hear this argument a lot, but it feels like a weird back-justification for the restrictions imposed by the government.
Yes, encryption would make some enforcement actions slightly harder, but we tolerate it in plenty of other settings where you have a constrained, shared resource. Wifi comes to mind. Nobody gets upset that you can't examine your neighbors' packets to make sure they're following the law or not using the spectrum for a purpose other than "bona fide" home wifi. Even though the wifi spectrum in urban areas is far more crowded than ham frequencies.
For much of the hobby's history, the government was deeply distrustful of amateur radio. They flat out banned all operations during WWI and WWII. And a lot of ham radio folks reminisce about the good old times when the government had listening stations and amateur radio enforcement operations throughout the country, and would knock on the doors of any amateurs who did anything wrong. Well, they funded that not because they shared your passion, but because they wanted to keep Soviet spies at bay.
The ban on encryption was supposed to serve the government's interests, nothing more. If you worry about corporations misusing the spectrum, it's sufficient to require identification in plain text; if somebody is using amateur callsigns but sending 9-to-5 chatter on a fixed frequency every day, and you pinpoint it to a local warehouse, that's more enough for enforcement action, right? Except... there is almost no enforcement these days, because the Cold War is over and the government lost all interest.
Ham radio getting "banned in unstable countries" seems like a whimsical concern, too. First, many other countries do not restrict encryption the way US does. Secondly, in the era of the Internet, mesh networking, ubiquitous smartphones, etc, ham radio hardly registers on the radar for most governments. Maybe in North Korea... so let's ban encryption domestically, including in the short-distance VHF/UHF band, to stay on Kim's good side?
Yes, encryption would make some enforcement actions slightly harder, but we tolerate it in plenty of other settings where you have a constrained, shared resource. Wifi comes to mind. Nobody gets upset that you can't examine your neighbors' packets to make sure they're following the law or not using the spectrum for a purpose other than "bona fide" home wifi. Even though the wifi spectrum in urban areas is far more crowded than ham frequencies.
For much of the hobby's history, the government was deeply distrustful of amateur radio. They flat out banned all operations during WWI and WWII. And a lot of ham radio folks reminisce about the good old times when the government had listening stations and amateur radio enforcement operations throughout the country, and would knock on the doors of any amateurs who did anything wrong. Well, they funded that not because they shared your passion, but because they wanted to keep Soviet spies at bay.
The ban on encryption was supposed to serve the government's interests, nothing more. If you worry about corporations misusing the spectrum, it's sufficient to require identification in plain text; if somebody is using amateur callsigns but sending 9-to-5 chatter on a fixed frequency every day, and you pinpoint it to a local warehouse, that's more enough for enforcement action, right? Except... there is almost no enforcement these days, because the Cold War is over and the government lost all interest.
Ham radio getting "banned in unstable countries" seems like a whimsical concern, too. First, many other countries do not restrict encryption the way US does. Secondly, in the era of the Internet, mesh networking, ubiquitous smartphones, etc, ham radio hardly registers on the radar for most governments. Maybe in North Korea... so let's ban encryption domestically, including in the short-distance VHF/UHF band, to stay on Kim's good side?
It's not just that.. The thing is also that if everyone starts using encryption the community is gone.
Right now at night we turn on the radios and check the local repeaters for activity and whatnot. Hear some interesting QSOs. If everyone is chatting encrypted this won't work.
It also would enable people to use it as a free alternative for a commercial license - after all when it's encrypted we can't check that it's not used for such a purpose anymore. Using locations as you suggest isn't enough as it will need really targeted surveillance. Also, for a warehouse any of the free radio modes are more than sufficient in range.
The ban on encryption isn't really much to do with espionage. Spies don't need a license.
Right now at night we turn on the radios and check the local repeaters for activity and whatnot. Hear some interesting QSOs. If everyone is chatting encrypted this won't work.
It also would enable people to use it as a free alternative for a commercial license - after all when it's encrypted we can't check that it's not used for such a purpose anymore. Using locations as you suggest isn't enough as it will need really targeted surveillance. Also, for a warehouse any of the free radio modes are more than sufficient in range.
The ban on encryption isn't really much to do with espionage. Spies don't need a license.
I think I addressed your second point above; for the first one, I think the ham community is largely gone at this point.
As you note, there are something like 700,000 licensed people in the US, but if you tune in to your local repeater and listen for a month, you will hear the same 2-8 people, typically in their 70s - and that's about it. They're there due to force of habit, and when they die, they're not going to be replaced. The same demographics can be observed for most ham clubs, maybe outside the SF Bay Area (where the median age is closer to 50).
So what are we really protecting here - a "community" representing and speaking on behalf of maybe 0.1% of all licensed individuals? Is this something to treasure, or should we bite the bullet and instead encourage a larger group of people to build something new?
And I hate to say this, but I think this situation is of their own doing. The old-timers wanted all the newcomers to follow in their footsteps and get excited in exactly the same things. As evidenced in the community-developed ham exam, which deals with such exciting and timely topics as tuning vacuum tube amplifiers, receiving analog slow-scan TV signals, memorizing Morse code shorthands, and DX contests that lost most of their "oomph" when the Internet showed up.
Meanwhile, VFH / UHF handheld-to-handheld messaging is still an elusive technology, and many old-timers don't consider anything above HF to be "real ham".
As you note, there are something like 700,000 licensed people in the US, but if you tune in to your local repeater and listen for a month, you will hear the same 2-8 people, typically in their 70s - and that's about it. They're there due to force of habit, and when they die, they're not going to be replaced. The same demographics can be observed for most ham clubs, maybe outside the SF Bay Area (where the median age is closer to 50).
So what are we really protecting here - a "community" representing and speaking on behalf of maybe 0.1% of all licensed individuals? Is this something to treasure, or should we bite the bullet and instead encourage a larger group of people to build something new?
And I hate to say this, but I think this situation is of their own doing. The old-timers wanted all the newcomers to follow in their footsteps and get excited in exactly the same things. As evidenced in the community-developed ham exam, which deals with such exciting and timely topics as tuning vacuum tube amplifiers, receiving analog slow-scan TV signals, memorizing Morse code shorthands, and DX contests that lost most of their "oomph" when the Internet showed up.
Meanwhile, VFH / UHF handheld-to-handheld messaging is still an elusive technology, and many old-timers don't consider anything above HF to be "real ham".
Analog slow-scan TV is cool as hell. I got a freakin' image transmitted to me by the international space station?! Nothing "old-timer" about that at all, and was one of the most interesting things I found as a newcomer to amateur radio :)
> As evidenced in the community-developed ham exam, which deals with such exciting and timely topics as tuning vacuum tube amplifiers, receiving analog slow-scan TV signals, memorizing Morse code shorthands, and DX contests that lost most of their "oomph" when the Internet showed up.
That's a lot of text to just tell everyone you made up a bunch of shit. None of that shit is on licensing exams. What is on the exams are things demonstrating you've got enough knowledge to not electrocute yourself, not get RF burns, not turn your radio into a jamming device, and understand the etiquette for sharing very limited bandwidth available to amateurs.
That's a lot of text to just tell everyone you made up a bunch of shit. None of that shit is on licensing exams. What is on the exams are things demonstrating you've got enough knowledge to not electrocute yourself, not get RF burns, not turn your radio into a jamming device, and understand the etiquette for sharing very limited bandwidth available to amateurs.
Here are the question IDs from the 2019-2023 general and 2020-2024 extra pools.
Vacuum tube amplifier tuning: E7B09, https://hamstudy.org/browse/E4_2016/E7B
Analog slow scan television signal components: E2B10, https://hamstudy.org/browse/E4_2020/E2B
Morse code shorthands: G2C02, https://hamstudy.org/browse/E3_2015/G2C
Vacuum tube amplifier tuning: E7B09, https://hamstudy.org/browse/E4_2016/E7B
Analog slow scan television signal components: E2B10, https://hamstudy.org/browse/E4_2020/E2B
Morse code shorthands: G2C02, https://hamstudy.org/browse/E3_2015/G2C
Vacuum tube amplifiers are still current technology for the high power folks, especially home builders.
Some morse shorthand is useful. CQ for instance. QRM, QSO and many more are all used for voice as well.
However, I will not defend the old guard too far. I get tired of the right-wing boomer conversations pretty quickly. Everything was better in the past....blah blah
Some morse shorthand is useful. CQ for instance. QRM, QSO and many more are all used for voice as well.
However, I will not defend the old guard too far. I get tired of the right-wing boomer conversations pretty quickly. Everything was better in the past....blah blah
"I hear this argument a lot, but it feels like a weird back-justification for the restrictions imposed by the government."
I continue to be amazed at what I consider to be a very unexpected cultural intersection:
Technical, do it yourself, nearly exclusively male, out-hacking one another with radio bits ... but simultaneously vehemently defensive of, and slavishly adherent to, arbitrary government regulations that strictly limit what they can do with their hobby.
The deference to arbitrary authority in the HAM community is really jarring ...
I continue to be amazed at what I consider to be a very unexpected cultural intersection:
Technical, do it yourself, nearly exclusively male, out-hacking one another with radio bits ... but simultaneously vehemently defensive of, and slavishly adherent to, arbitrary government regulations that strictly limit what they can do with their hobby.
The deference to arbitrary authority in the HAM community is really jarring ...
This is an extremely ignorant position to take. For starters amateur licenses have mode and modulation restrictions in certain bands and power output limitations in all of them. Secondly despite far higher power privileges than unlicensed users amateurs have to keep their power output appropriate for their use. They can't just crank the output up to 11. Third, amateurs are prohibited from commercial communications and broadcasting on amateur bands.
Everyone with some sort of radio license from commercial broadcasters to amateurs have some sort of legal limits on their operation. Radio is a shared medium and being an asshole can ruin the medium for other uses over a huge area.
When it comes to encryption, good encryption is little different from noise. I also have no idea what you're doing on the band. Do you just have a mistuned radio? Are you overdriving your transmitter? What I do know is you're raising the noise floor on whatever band you're on and keeping me from using it.
Your WiFi being encrypted is a much different situation. Best case propagation is hundreds of feet and the PEP is so low that beyond a relatively short distance your transmissions literally blend into background noise for me. So your WiFi doesn't affect me too badly unless we're in adjacent apartments and you've got your output power maxed out.
Your encrypted transmissions on the rarified space available for hams ruins it for a lot of users over a wide area. That is why hams are fine with no encryption for amateur operation.
Everyone with some sort of radio license from commercial broadcasters to amateurs have some sort of legal limits on their operation. Radio is a shared medium and being an asshole can ruin the medium for other uses over a huge area.
When it comes to encryption, good encryption is little different from noise. I also have no idea what you're doing on the band. Do you just have a mistuned radio? Are you overdriving your transmitter? What I do know is you're raising the noise floor on whatever band you're on and keeping me from using it.
Your WiFi being encrypted is a much different situation. Best case propagation is hundreds of feet and the PEP is so low that beyond a relatively short distance your transmissions literally blend into background noise for me. So your WiFi doesn't affect me too badly unless we're in adjacent apartments and you've got your output power maxed out.
Your encrypted transmissions on the rarified space available for hams ruins it for a lot of users over a wide area. That is why hams are fine with no encryption for amateur operation.
I know people that would gladly use ham bands for business uses, and with encryption allowed it would be "just another encrypted QSO". And the ham bands would slowly fill up with non-ham use.
I know these people too, and its a little odd since commercial/business licenses in the VHF/UHF part 90 bands are dirt cheap - a few hundred dollars for a ten year license, and no need to pass a test.
But...there's tons of projects already in use which use protocols that, if the regulatory body isn't following every open source project & actively updating their intake tools, effectively act as encryption schema.
Could you give me an example or two so I can better understand what you mean?
You're not entirely wrong, an undocumented plaintext protocol is functionally not much different from encryption.
However, those which are legitimate (ie, just undocumented, not intentionally encrypted/obfuscated) don't tend to cause problems as only one or few ham devs would be using them. They can only get widespread adoption by other hams if they are documented. So this regulates itself.
A corporation, on the other hand, is not like some ham dev coming up with their own protocol. They can design their own protocol, and then roll it out on thousands (or much more) of transmitters. So just one corporation can cause quite a big problem, with zero public documentation.
The laws as they are, together with direction finding skills, are the communities only (legal) tool to defend against that.
That does not mean hams don't see the value in encryption. I do! But it's a trade-off, and I think this is the only way it can work. The legal change I would like to see is explicitly allowing cryptographic signatures. Right now it's a grey area (likely legal, but not court tested)
You're not entirely wrong, an undocumented plaintext protocol is functionally not much different from encryption.
However, those which are legitimate (ie, just undocumented, not intentionally encrypted/obfuscated) don't tend to cause problems as only one or few ham devs would be using them. They can only get widespread adoption by other hams if they are documented. So this regulates itself.
A corporation, on the other hand, is not like some ham dev coming up with their own protocol. They can design their own protocol, and then roll it out on thousands (or much more) of transmitters. So just one corporation can cause quite a big problem, with zero public documentation.
The laws as they are, together with direction finding skills, are the communities only (legal) tool to defend against that.
That does not mean hams don't see the value in encryption. I do! But it's a trade-off, and I think this is the only way it can work. The legal change I would like to see is explicitly allowing cryptographic signatures. Right now it's a grey area (likely legal, but not court tested)
Great points, especially,
> They can only get widespread adoption by other hams if they are documented.
> So this regulates itself
Until the first project gets traction that allows you to easily drop in public/private key encryption of payload.
> They can only get widespread adoption by other hams if they are documented.
> So this regulates itself
Until the first project gets traction that allows you to easily drop in public/private key encryption of payload.
I'm not sure what asymmetric encryption has to do with this.
There are already protocols that are widely used in ham radio that support encryption. For example, DMR supports encryption (because DMR can also operate in commercial bands, under different laws), it's just not used for ham radio and I've never seen a ham turn it on. Wifi supports encryption, and ham radio operators using it in ham radio bands (with more power) actually turn encryption on but document the PSK publicly (in an attempt to keep the non hams out, but make the encryption more an encoding that anyone could decode).
In my experience, ham radio operators generally roughly follow the rules.
There are already protocols that are widely used in ham radio that support encryption. For example, DMR supports encryption (because DMR can also operate in commercial bands, under different laws), it's just not used for ham radio and I've never seen a ham turn it on. Wifi supports encryption, and ham radio operators using it in ham radio bands (with more power) actually turn encryption on but document the PSK publicly (in an attempt to keep the non hams out, but make the encryption more an encoding that anyone could decode).
In my experience, ham radio operators generally roughly follow the rules.
Is this explicitly allowed? I've always thought it would be cool if amateurs were allowed to encrypt their communications, so long as they provided the decryption keys regularly over the same channel.
You could incorporate cryptographic signatures, diffie-helmann key exchanges, all kinds of fun stuff, and so long as you periodically transmit the decryption key, you're not hiding anything. I'm not sure what the legality of this is.
You could incorporate cryptographic signatures, diffie-helmann key exchanges, all kinds of fun stuff, and so long as you periodically transmit the decryption key, you're not hiding anything. I'm not sure what the legality of this is.
It's thought to be legal but it is not explicitly allowed, and so it requires some legal interpretation and that is not court tested.
Would somebody please, please produce a very high quality, rugged, handheld radio case that can hold a raspberry pi zero and an RTL-SDR ?
So, not a computer, not a smartphone - a plain old motorola-esque handheld radio with physical buttons and a simple screen - but underneath, it's an extensible SDR platform.
Why doesn't this exist ?
So, not a computer, not a smartphone - a plain old motorola-esque handheld radio with physical buttons and a simple screen - but underneath, it's an extensible SDR platform.
Why doesn't this exist ?
Rugged cases are extremely expensive and become affordable only through economics of scale that exceed an enthusiast project. You could pay for custom plastic molding and waterproofing if you wanted to, but the price would shock you. Look at how even projects as relatively large and established as Pine64 products are unable to get quality cases without becoming too expensive for what its community is willing to pay.
Okay, we'll need an rtl-sdr, a raspberry pi, a battery, a keypad, and a screen. We can 3d print a case, or put it in a project box. Both can be ruggedized later.
I found this for the keypad and screen: https://wiki.dfrobot.com/I_O_Expansion_HAT_for_Pi_zero_V1_0_...
There are separate options for keypad and screen, e.g eink and a number pad, but for a first pass this might be enough.
An rtl-sdr won't plug directly into a pi zero w, so we'll need an internal adapter. I know that HATs stack, so if there isn't a hard requirement for an rtl-sdr, we could find an sdr hat to put between the pi and the keypad.
I found this for the keypad and screen: https://wiki.dfrobot.com/I_O_Expansion_HAT_for_Pi_zero_V1_0_...
There are separate options for keypad and screen, e.g eink and a number pad, but for a first pass this might be enough.
An rtl-sdr won't plug directly into a pi zero w, so we'll need an internal adapter. I know that HATs stack, so if there isn't a hard requirement for an rtl-sdr, we could find an sdr hat to put between the pi and the keypad.
Making the case is the “rest of the fucking owl”, like there hadn’t been a successful attempt at making silicone membrane keypads found on cheapest TV remotes in homebrew hardware scene.
There are some other outdoor keypad options - tv remotes, security gates, garage door openers, etc.
The case doesn't need to be special for a first pass. We just need enough of a fucking owl to decide what to do next.
https://i.imgur.com/KmaZLNy.jpg
Edit: my plan was to find a configuration of hardware that does what we want to do first. Next would be trying the new platform from a desk and, if that goes well, designing a case for the parts we selected. You can't really make a custom case without knowing what's going inside :)
The case doesn't need to be special for a first pass. We just need enough of a fucking owl to decide what to do next.
https://i.imgur.com/KmaZLNy.jpg
Edit: my plan was to find a configuration of hardware that does what we want to do first. Next would be trying the new platform from a desk and, if that goes well, designing a case for the parts we selected. You can't really make a custom case without knowing what's going inside :)
Great idea about the eink display, any way to save battery power is good, plus, the readability of the eink displays is fantastic.
Gotta have a robust water resistant keyboard though.
You can get a cheap Chinese radio and run OpenGD77 [1] on it. Not exactly Raspberry Pi with RTL-SDR, but still open source.
[1] https://github.com/rogerclarkmelbourne/OpenGD77
[1] https://github.com/rogerclarkmelbourne/OpenGD77
Very interesting - thank you!
But that's not really a handheld radio; it's a scanner. An RTL-SDR doesn't transmit.
The most common usage of the term "handheld radio" refers to a receive-only device for the AM/FM bands, not a transceiver.
Case design and manufacturing is probably far more expensive than you think. Quality cases even more so. Rugged cases would probably astound you.
I'd love a device like this, but I don't think a raspi zero has enough processing power. My raspi 4 has a very hard time decoding P25 as it is, and that's with active cooling. Probably the best solution would be to offload the decoding to an FPGA, but that kind of blows up the whole "software defined" part.
Have you tried a hackrf portapack? It's an order of magnitude more expensive than a pi zero and an rtl-sdr, but it might be close to what you want.
You can always design one yourself. Analogue Devices offers many chips that are SDRs-on-a-wafer. The AD9361 is a particularly popular chip.
No, the innards already exist - a raspberry pi zero and a rtl-sdr.
I am suggesting a nicely made, high quality, plastic case - with buttons and screen - that has slots and mounting screws inside to insert a raspi zero and a USB dongle inside.
I quite like the standard handheld radio form factor - like this:
https://www.motorolasolutions.com/en_us/products/two-way-rad...
... I just want a linux computer and an RTL-SDR inside ...
I am suggesting a nicely made, high quality, plastic case - with buttons and screen - that has slots and mounting screws inside to insert a raspi zero and a USB dongle inside.
I quite like the standard handheld radio form factor - like this:
https://www.motorolasolutions.com/en_us/products/two-way-rad...
... I just want a linux computer and an RTL-SDR inside ...
What people are trying to convey to you is your innate choices are very poor and recommending better picks.
Not just for you, but for other readers who may try to follow in your (poorly thought out) steps.
[deleted]
Oh sorry, I misread.
Put together a team, design it, make some renderings and run a Crowd Funding Op, I'd consider contributing.
The most rugged handheld radio, for rock climbers, whitewater rafters, skiers: https://rockytalkie.com. Just no raspi. I just got a pair and they're incredibly well designed. The rubber case can be removed to make them even lighter. It comes with a full-strength rock climbing carabiner.
To be honest I've seen a lot radios a lot more rugged than that. Like what the military uses.
Our ham radios are generally only semi-rugged: Waterproof and can take a bit of a fall but nothing like what the military have. Of course those come with a weight penalty too.
Our ham radios are generally only semi-rugged: Waterproof and can take a bit of a fall but nothing like what the military have. Of course those come with a weight penalty too.
related: https://m17project.org/
I live in a remote area where Ham radio is still a vital communication protocol during power outages and such, but lately groups of non Hams (preppers, and such) have decided that buying those cheap FRS radios will serve them during an emergency.
And some of those groups are pushing people to get their FCC Ham license and use VHF radios because they can be used over greater distances.
Unfortunately, almost none of those folks are actually practicing with their radios to become comfortable using them.
So when an emergency occurs, they have no idea of what to do on the air, and they will cause harmful interference because they are willfully ignorant of the local communication protocols already set up by generations of Ham operators.
They will be a part of the problem, not a part of the solution.
I put on a "Jump Bag" presentation every year in my small town, and I warn folks that if they get an FRS radio or Ham radio, that they need to practice with it and become comfortable using it, otherwise they will not be helpful during an emergency, and will cause problems with the coordinated Hams.
Aside from that, I also recommend against getting an FRS radio unless they are willing to make sure the batteries in them are replaced on a regular basis, otherwise when the emergency occurs, they will find a dead FRS radio with corroded battery contacts, basically a paperweight and nothing more.
73, KE6---
And some of those groups are pushing people to get their FCC Ham license and use VHF radios because they can be used over greater distances.
Unfortunately, almost none of those folks are actually practicing with their radios to become comfortable using them.
So when an emergency occurs, they have no idea of what to do on the air, and they will cause harmful interference because they are willfully ignorant of the local communication protocols already set up by generations of Ham operators.
They will be a part of the problem, not a part of the solution.
I put on a "Jump Bag" presentation every year in my small town, and I warn folks that if they get an FRS radio or Ham radio, that they need to practice with it and become comfortable using it, otherwise they will not be helpful during an emergency, and will cause problems with the coordinated Hams.
Aside from that, I also recommend against getting an FRS radio unless they are willing to make sure the batteries in them are replaced on a regular basis, otherwise when the emergency occurs, they will find a dead FRS radio with corroded battery contacts, basically a paperweight and nothing more.
73, KE6---
How will FRS users cause harmful interference on the ham bands? I think FRS is pretty amazing for what it is. It builds confidence if practiced in its simplicity and there are FRS neighborhood nets run by ham radio operators as well.
I was surprised to find that during an emergency, FM broadcast reception alone can be an awesome solution for many, if not most. Some friends wandered over to my ham shack to ask if that was where the action was, but most of my information came from the local public/NPR station's hourly reports. (The ham repeaters were useful for hyper-local fire spotting, and generator/gear questions.)
I was surprised to find that during an emergency, FM broadcast reception alone can be an awesome solution for many, if not most. Some friends wandered over to my ham shack to ask if that was where the action was, but most of my information came from the local public/NPR station's hourly reports. (The ham repeaters were useful for hyper-local fire spotting, and generator/gear questions.)
How will FRS users cause harmful interference on the ham bands?
BaoFeng units can transmit on a wide range of frequencies, and non-ham users with no clue as to what's permitted can blither all over a big chunk of spectrum. BaoFeng also added a button that transmits an electronic siren sound, allowing idiots to annoy people for miles around. Further if they hit a repeater. The things are very cheap; about $10 each in quantity 6.
BaoFeng units can transmit on a wide range of frequencies, and non-ham users with no clue as to what's permitted can blither all over a big chunk of spectrum. BaoFeng also added a button that transmits an electronic siren sound, allowing idiots to annoy people for miles around. Further if they hit a repeater. The things are very cheap; about $10 each in quantity 6.
Are you implying that FRS users and Baofeng users are one and the same? This is definitely not true if so.
In my neighborhood as one example, FRS users purchase from one of the local or local chain stores, which carry Cobra, Midland, or Motorola radios.
Even if you purchase from Amazon, they changed their rules some time ago and require proper FCC certification on all radios. This means that you can't buy an FRS radio from Amazon which will let you do what you said. Even the Baofeng FRS units will come without the ability to go into ham bands.
And even then, if you managed to buy FRS radios without FCC certification, they come pre-programmed with FRS channels (so that they do what the label says they do) and would have to be programmed manually to use ham frequencies. I'm not sure which FRS users would or could realistically go through the trouble to do that, if any.
In my neighborhood as one example, FRS users purchase from one of the local or local chain stores, which carry Cobra, Midland, or Motorola radios.
Even if you purchase from Amazon, they changed their rules some time ago and require proper FCC certification on all radios. This means that you can't buy an FRS radio from Amazon which will let you do what you said. Even the Baofeng FRS units will come without the ability to go into ham bands.
And even then, if you managed to buy FRS radios without FCC certification, they come pre-programmed with FRS channels (so that they do what the label says they do) and would have to be programmed manually to use ham frequencies. I'm not sure which FRS users would or could realistically go through the trouble to do that, if any.
The BaoFengs can, last I checked, transmit on 2m, 70cm, and the FRS band. I don’t remember if the modulation is exactly right on FRS.
Sounds like you're thinking of non-FRS, non-FCC-licensed radios? Top Amazon results for "Baofeng FRS" here are the GT-22 and BF-88ST. Both are FCC certified, e.g. FCC ID 2AJGM-BF88ST. No VFO, UHF only. You turn it on and you're stuck on FRS freqs.
(It seems to me that the Baofeng danger-danger straw man gets larger by the day but it's still straw, and unfair given that licensing is done and specs are met.)
(It seems to me that the Baofeng danger-danger straw man gets larger by the day but it's still straw, and unfair given that licensing is done and specs are met.)
Nope. Baofeng UV-5R lists:
Frequency range:
[TX] 136 – 174MHz, 400 – 520MHz
[RX] 136 – 174MHz, 400 – 520MHz, 68-108MHz (FM Broadcast)
Like I said, the UV-5R isn't licensed or marketed as an FRS radio...this isn't a general Baofeng complain-a-thon, it's a thread that started with an unreasonable complaint that FRS users cause harmful interference on the ham bands. You hopped on with Baofeng tech specs, and I humored this, but now I have to say you've completely derailed the thread into nothing but Baofeng specs, a seemingly meaningless exercise given the thread contents. If this thread is going to continue for another week or two, could we at least get back into the proper context?
In fact it's extremely rare to find an FRS user with a radio like a UV-5R. Most of them are using Motorola Talkabouts, or Cobras, or Midland radios.
Another part of the reason for the lack of popularity is that people like to buy brand-name, popular radios that their friends recommend, and another part is that Baofeng does a better job advertising their FRS radios that are purpose-built for FRS. People shopping for an FRS radio like to buy something that says "FRS" on the box.
(The only person I ever met who used a Baofeng on FRS frequencies was a licensed GMRS user, and their use was 100% OK, of course)
In fact it's extremely rare to find an FRS user with a radio like a UV-5R. Most of them are using Motorola Talkabouts, or Cobras, or Midland radios.
Another part of the reason for the lack of popularity is that people like to buy brand-name, popular radios that their friends recommend, and another part is that Baofeng does a better job advertising their FRS radios that are purpose-built for FRS. People shopping for an FRS radio like to buy something that says "FRS" on the box.
(The only person I ever met who used a Baofeng on FRS frequencies was a licensed GMRS user, and their use was 100% OK, of course)
Many things that transmit do so poorly with a lot of spurious emission in nearby or harmonic bands. In other words, the signal coming out of those radios is so wide it bleeds into the ham bands. The signals are fairly weak but can add to the background noise level.
"Many things" is not specific enough. Can you be more specific?
This used to be true of a few models of ham radios, but A) the manufacturers have largely fixed that situation, B) those were mostly sold as ham radios and we're talking here about COTS FRS radios, which are easily testable and there are no complaints I could find online, and C) these are also 2W LOS radios which cannot legally be sold with a numeric keypad or be fitted with a new antenna. Not exactly a threat to local amateur operations... Oh and D) In years of operation I've never had a single problem from either others' spurious emissions affecting my operations or FRS users on the ham bands.
This used to be true of a few models of ham radios, but A) the manufacturers have largely fixed that situation, B) those were mostly sold as ham radios and we're talking here about COTS FRS radios, which are easily testable and there are no complaints I could find online, and C) these are also 2W LOS radios which cannot legally be sold with a numeric keypad or be fitted with a new antenna. Not exactly a threat to local amateur operations... Oh and D) In years of operation I've never had a single problem from either others' spurious emissions affecting my operations or FRS users on the ham bands.
How do you recommend practicing? I often have trouble with the basics, like connecting to repeaters. When I do, I don't hear much traffic or it seems like a semi-private conversation where it would feel "rude" to say something.
Do I just keep talking into the void and waiting?
Also, I have cheap equipment, so scanning is really slow and I don't know if it even really works. I can make simplex connections on 70cm and 2m with friends when I prearrange, but that's it.
I don't have tons of time but if I felt like I could hop into a conversation and be welcome (and others would be patient) then I would sometimes.
Do I just keep talking into the void and waiting?
Also, I have cheap equipment, so scanning is really slow and I don't know if it even really works. I can make simplex connections on 70cm and 2m with friends when I prearrange, but that's it.
I don't have tons of time but if I felt like I could hop into a conversation and be welcome (and others would be patient) then I would sometimes.
I'm assuming you're talking amateur radio here, doing VHF/UHF on repeaters. Especially assuming you're on an HT, find the closest repeaters to you. Periodically just throw out your call sign on the repeater and listen. Throwing out a call on the repeater is the normal way to just let people know you're there and listening.
Experiences vary a good bit based on location and ability to transmit. You'll be able to hit far more repeaters if you have a mobile setup or the ability to operate a decent bit of power from your home safely. I live in a pretty metropolitan area and can easily hit or at least listen to a dozen or so repeaters in the area on 25W on a mobile with a j-pole in my attic. When I had access to a multi-story parking garage I had somewhat similar access with just a handheld and a decent whip antenna. Getting altitude can make a good bit of difference in making waves.
Experiences vary a good bit based on location and ability to transmit. You'll be able to hit far more repeaters if you have a mobile setup or the ability to operate a decent bit of power from your home safely. I live in a pretty metropolitan area and can easily hit or at least listen to a dozen or so repeaters in the area on 25W on a mobile with a j-pole in my attic. When I had access to a multi-story parking garage I had somewhat similar access with just a handheld and a decent whip antenna. Getting altitude can make a good bit of difference in making waves.
Eternal September is the natural state of walled gardens as soon as you open the gates.
As rude as RTFM sounds, it's the only antidote.
As rude as RTFM sounds, it's the only antidote.
Are they lacking technical skills or social/tribal knowledge or both?
There are plenty of Hams willing to help them, but this subset of people feel they don't "need" to practice, they can't grok the consequences of their inaction.
I've had many discussions with these type of folks, and for them it's almost like a merit badge to get a radio and talk it up, but they never learn how to use them because they don't feel they need to.
They just don't want to take the time to become familiar/proficient with that particular "tool".
It's quite similar to some gun owners who purchase a handgun and then never learn how to safely handle it, and never go to a range and practice with it.
It appears to me, to be a cultural/generational problem of over assessment of their own abilities.
I've had many discussions with these type of folks, and for them it's almost like a merit badge to get a radio and talk it up, but they never learn how to use them because they don't feel they need to.
They just don't want to take the time to become familiar/proficient with that particular "tool".
It's quite similar to some gun owners who purchase a handgun and then never learn how to safely handle it, and never go to a range and practice with it.
It appears to me, to be a cultural/generational problem of over assessment of their own abilities.
What do they do that is damaging? I think that's what they were asking. Do they just clog the airwaves with noise?
Sorry I misunderstood.
Yes, those who have Ham radios and don't know the protocols will cause interference because they don't understand how emergency communications occur.
It's a strict protocol called a "Net", used to minimize Errors, which can be life threatening under emergency conditions.
I've seen it happen during minor earthquakes and tsunami alerts, they become a problem, and in no way are contributing to the solution.
Too much Noise, not enough Signal, interferes with emergency communications.
Ham radio isn't a panacea, it's not going to help you unless you know how to use the "tool" properly.
Yes, those who have Ham radios and don't know the protocols will cause interference because they don't understand how emergency communications occur.
It's a strict protocol called a "Net", used to minimize Errors, which can be life threatening under emergency conditions.
I've seen it happen during minor earthquakes and tsunami alerts, they become a problem, and in no way are contributing to the solution.
Too much Noise, not enough Signal, interferes with emergency communications.
Ham radio isn't a panacea, it's not going to help you unless you know how to use the "tool" properly.
I'm curious what you think the solution is. I have my ham license and work in commercial radio, so I certainly have an idea of how the tools work. But even in an area with a lot of repeaters, there is pretty limited activity at any given time, so what are people supposed to do to get experience? ARES/RACES type emergency response groups practicing for cold war, pre-internet type threats don't appeal to everyone.
Sadly, the digital protocols for local use in the VHF/UHF bands available to new hams (2m / 70 cm) are generally boring 1980/90s-esque technology. Would be nice if a newer system came about for messaging and bulletin board type systems - voice doesn't scale.
Sadly, the digital protocols for local use in the VHF/UHF bands available to new hams (2m / 70 cm) are generally boring 1980/90s-esque technology. Would be nice if a newer system came about for messaging and bulletin board type systems - voice doesn't scale.
APRS works decently well for things like messaging and bullitens and has some interesting web connectivity possible. In my area the normal 1200 baud 144.390MHz is quite crowded but a number of digipeaters and I-Gates operate on a 9600 baud 70cm frequency as well.
Also there's some metro area WiFi mesh networks which operate in amateur spectrum. That's a good bit of fun.
Also there's some metro area WiFi mesh networks which operate in amateur spectrum. That's a good bit of fun.
APRS is interesting, but again - I'm not sure a 1200/9600 baud narrowband system is going to scale in a real emergency (for two way communication at least, for broadcast information its probably enough).
What about DMR? It supports direct, two-way text messaging.
I'm not the OP but it sounds like they're not doing anything right now. Which is the problem. What he's afraid of is that during an actual disaster they'll all go on the air and have no clue how things work.
Correct.
But Not afraid, I've already seen it happen.
Thanks for clarifying.
But Not afraid, I've already seen it happen.
Thanks for clarifying.
What do you think of Iridium satellite text messaging as an alternative to Ham radio for emergencies? There are fairly inexpensive devices available now like the Garmin Inreach.
When people talk about harmful elitism in ham, this
>They will be a part of the problem, not a part of the solution.
is what is party behind it.
Are you saying cellphones for everyone are harmful because emergency lines are usually ddossed during an emergency? Yes there is a difference in channel access but cheap radios provide you with the very important capability of being able to listen and most people are not stupid, and abusing your radio will end up killing the battery anyway.
Ie. you are overestimating the issues caused and not taking into account all the positives they provide.
>They will be a part of the problem, not a part of the solution.
is what is party behind it.
Are you saying cellphones for everyone are harmful because emergency lines are usually ddossed during an emergency? Yes there is a difference in channel access but cheap radios provide you with the very important capability of being able to listen and most people are not stupid, and abusing your radio will end up killing the battery anyway.
Ie. you are overestimating the issues caused and not taking into account all the positives they provide.
Well someone that doesn't know how to use a ham radio could easily transmit where they're not supposed to, quite possibly causing interference. Your cellphone won't do that.
Is there any commercial radio for private use with proper encryption?
It seems the only ones you can find are limited to 48 bit key or so.
It seems the only ones you can find are limited to 48 bit key or so.
There's not much market for them, that's the issue.
You can't use much transmit power on a free license. And hams are not allowed to use encryption as a licensing condition. The idea behind this is that you're a community. It's not really meant for private communication.
Some business radios offer excellent encryption but can only be used with an expensive commercial license.
The Family radio service ones are more for like walky talky use on the go where encryption isn't so important, and they have more limited range.
You can't use much transmit power on a free license. And hams are not allowed to use encryption as a licensing condition. The idea behind this is that you're a community. It's not really meant for private communication.
Some business radios offer excellent encryption but can only be used with an expensive commercial license.
The Family radio service ones are more for like walky talky use on the go where encryption isn't so important, and they have more limited range.
I was asking about walky talkies.
For some reason strong encryption is only allowed for gov use (emergency services, ...)
Since they do have weak encryption, there does seem to be some demand for that.
For some reason strong encryption is only allowed for gov use (emergency services, ...)
Since they do have weak encryption, there does seem to be some demand for that.
Motorola's RMM2050, a license-free MURS radio, has a built-in scrambler which I just assume is not great. It's got headset I/O so I don't think there's any reason you couldn't use a more effective scrambling headset.
https://shop.motorolasolutions.com/rmm2050-two-way-radio-for...
No idea what your application is but since you said "strong encryption" the idea of using a MURS radio modem kind of sprang to mind. Some examples:
https://www.raveon.com/license-free-radio-modems/
https://www.esteem.com/esteem-products/
https://shop.motorolasolutions.com/rmm2050-two-way-radio-for...
No idea what your application is but since you said "strong encryption" the idea of using a MURS radio modem kind of sprang to mind. Some examples:
https://www.raveon.com/license-free-radio-modems/
https://www.esteem.com/esteem-products/
Ah maybe that's a US specific thing. Business radio licensees here in Europe have access to the same strong encryption that the government use.
It's available to business radio licensees in the US, too.
And hams are not allowed to use encryption as a licensing condition.
But are they allowed to use steganography...? Same difference, really.
But are they allowed to use steganography...? Same difference, really.
Not really either no. Of course by its very nature steganography is hidden. So it's hard to detect.
Really the communication we can have is quite restricted. The same reason we're not allowed to broadcast 'radio programs' as such (with the exception of the weekly news reading etc). Some countries also prohibit political or religious discussion. The license is meant to stimulate research and technical exploration. If you're looking for ways around it, you should consider whether this is really the hobby for you, as you probably want it for something it's not intended for. It's not a "production" communication service. It's a chance to build and explore technology.
There are some exceptions though like authentication and control systems for things like amateur satellites and repeaters. The same in emergencies: Encrypted emergency comms is allowed, such as passing personal messages from disaster-stricken areas. Of course things like personal details of survivors are not passed in the clear. But during normal ham operation these things are not allowed and for good reason.
Really the communication we can have is quite restricted. The same reason we're not allowed to broadcast 'radio programs' as such (with the exception of the weekly news reading etc). Some countries also prohibit political or religious discussion. The license is meant to stimulate research and technical exploration. If you're looking for ways around it, you should consider whether this is really the hobby for you, as you probably want it for something it's not intended for. It's not a "production" communication service. It's a chance to build and explore technology.
There are some exceptions though like authentication and control systems for things like amateur satellites and repeaters. The same in emergencies: Encrypted emergency comms is allowed, such as passing personal messages from disaster-stricken areas. Of course things like personal details of survivors are not passed in the clear. But during normal ham operation these things are not allowed and for good reason.
I assume you mean Digital Modes?
And it's not the same, because anyone can "read" the digital message with the same codec, encription can't be, unless one has the key.
And it's not the same, because anyone can "read" the digital message with the same codec, encription can't be, unless one has the key.
Project 25 radios are commercially available and can use 256 bit AES. The business radio license required isn't difficult or expensive to get, but the hardware and programming is probably a little too expensive for most people.
Most P25 radios also require a specialized device (keyloader) for loading encryption keys that's separate from the vendor's programming software for channels and other parameters. Used keyloaders that support AES-256 still go for $2,000+ (Motorola KVL3000+/KVL4000).
A couple years ago I developed an open source one:
https://github.com/KFDtool/KFDtool
A couple years ago I developed an open source one:
https://github.com/KFDtool/KFDtool
Here's a handful of Kenwood radios that support DES/AES: https://comms.kenwood.com/en/solutions/functions/list.php?fu...
I know the Baofeng UV5R's are cheap but hear me out. I've gotten some great use out of mine. Lots of preppers have these. Because they're so ubiquitous parts and know-how are easy to come by.
If you want to buy radio that you're never going to use, or probably won't take the time to learn, get the Baofeng and save your money. Don't wait for "perfect". Good enough is better than nothing when the SHTF.
If you want to buy radio that you're never going to use, or probably won't take the time to learn, get the Baofeng and save your money. Don't wait for "perfect". Good enough is better than nothing when the SHTF.
Wait... the UV5R is a HAM radio? I'm totally naïve to the HAM and with the zombie apocalypse continuing, got the time to spend on those bucket list items. These things are only $35 bucks! That is screw around money.
At some point, I'll need to deal with getting a radio license for doing some GA flights into Canada. Any chance this would pick up the 100 MHz bands (possibly using the term wrong) to pick up aviation ATIS?
At some point, I'll need to deal with getting a radio license for doing some GA flights into Canada. Any chance this would pick up the 100 MHz bands (possibly using the term wrong) to pick up aviation ATIS?
The relationship between dubiously certified imported radios (e.g. Baofeng) and US radio services is a complex one. Baofeng products are radios which are not exactly any "type" of radio, and are technically illegal for most applications, but are dubiously legal in some cases for amateur radio use (this relates to an odd detail of FCC regulations with regards to type certification of devices, some Baofeng models are legal but others are not). The bottom line is that it's complicated, but they are capable of receiving and transmitting on amateur bands and they are very cheap, so they are often used for that purpose. This requires some caution as Baofeng models are more properly intended for business-band use (but are usually not certifiable for that purpose in the US) and so do things like default to wideband.
A lengthier explanation is that, put somewhat simply and as a result somewhat incorrectly, in the amateur radio service the certification belongs to the operator, while in most other services the certification belongs to the radio. This means that any radio may be used in the amateur service if it is operated by a licensed individual, which is useful since amateur radio operators will often make use of hand-built radios or radios manufactured for other services and modified. From this perspective, it is legal for a licensed amateur operator to use any arbitrary radio. However, it is generally not legal to sell any radio which is not certified under some part of the FCC regulations. Most Baofeng models have never been certified under any part of the FCC regulations and cannot be for various reasons (e.g. face programmability which is prohibited for most land mobile services). This results in a bit of a "fruit of a poison tree" situation: while it is not necessarily illegal for a licensed amateur operator to use a UV-5R, that UV-5R was mostly likely sold in violation of the regulations. FCC enforcement on this issue has been very lax, but the action taken recently against Rugged Radios (a reseller of Baofengs) suggests to some that the FCC may be intending to clamp down. There is some practical implication as some independent labs and amateurs have concluded that Baofeng models do not meet FCC regulations with regards to spurious emissions and harmonics and therefore may interfere with licensed use of bands.
Aviation radio is wideband AM for historic reasons, most cheap handhelds like Baofeng models are FM only. Fortunately dedicated aviation handhelds are fairly inexpensive and can be found with useful features like aviation dual plugs for your headset and even VOR display.
A lengthier explanation is that, put somewhat simply and as a result somewhat incorrectly, in the amateur radio service the certification belongs to the operator, while in most other services the certification belongs to the radio. This means that any radio may be used in the amateur service if it is operated by a licensed individual, which is useful since amateur radio operators will often make use of hand-built radios or radios manufactured for other services and modified. From this perspective, it is legal for a licensed amateur operator to use any arbitrary radio. However, it is generally not legal to sell any radio which is not certified under some part of the FCC regulations. Most Baofeng models have never been certified under any part of the FCC regulations and cannot be for various reasons (e.g. face programmability which is prohibited for most land mobile services). This results in a bit of a "fruit of a poison tree" situation: while it is not necessarily illegal for a licensed amateur operator to use a UV-5R, that UV-5R was mostly likely sold in violation of the regulations. FCC enforcement on this issue has been very lax, but the action taken recently against Rugged Radios (a reseller of Baofengs) suggests to some that the FCC may be intending to clamp down. There is some practical implication as some independent labs and amateurs have concluded that Baofeng models do not meet FCC regulations with regards to spurious emissions and harmonics and therefore may interfere with licensed use of bands.
Aviation radio is wideband AM for historic reasons, most cheap handhelds like Baofeng models are FM only. Fortunately dedicated aviation handhelds are fairly inexpensive and can be found with useful features like aviation dual plugs for your headset and even VOR display.
UV5R can transmit and receive on the 2m amateur band as well as others. If you really want to have a go save up 100 bucks and get a Yaesu FT65 and get licensed (it's not hard). I started with the Baofeng thing and tried Summits On The Air (SOTA). Baofengs have very poor filtering which means if you are near a strong signal you probably won't hear anything. I was on a hilltop a couple of miles from a commercial radio mast...people could hear me, I couldn't hear them. Putting up a big antenna made the situation worse, because it drags in more signal in! With the Yaesu I have had 70 mile contacts summit to summit with the supplied antenna. Save your money and get a real one.
FYI, Lcamtuf's callsign seems to be K7TUF.
Enjoy ;)
Enjoy ;)
Sorry OP, got distracted reading the great comments.
If someone really wants to have communications ability beyond land lines and cell phones, which often Fail under emergency conditions, then for some people I recommend spending the time and effort in getting an Amateur (Ham) Radio License.
FRS radios are for local, close-by communications like inside theme parks, County Fairs and such, and have limited practicality in an emergency situation for several reasons.
But, Ham Radio, specifically the 2 Meter band, is a network with established emergency communications protocols that save lives every year all over the world, and it's all run and maintained by Volunteers!
It can also be used for non commercial, personal communications, but it's not like a cell phone which is mostly private, so anyone with a similar radio or radio scanner can listen in to your Ham radio conversations.
It's akin to talking to a friend in public or a restaurant.
Once one learns the Ham radio communication protocols, it's an amazing radio service to belong to, and if one is intellectually curious, you can follow multiple paths of interest within it, far beyond mere personal or emergency communications.
But, one has to learn and be comfortable with the Tool, because your Radio won't save you if you don't know how to use it.
For instance, changing the transmit and receive frequency during a stressful emergency, or actually knowing how long you can use it before the battery is depleted, and do you have spares, and are they kept charged?
If Not, you are back to being a part of the problem instead of the solution.
One can't be "the Hero" without planning and practicing beforehand, so learn the tool of the trade, so to speak, spend several months using and getting to know your radio.
Spend a lot of time on the air talking to other Hams, learn their call signs and the language of Ham Radio, and once you are "there" you'll be able to back off your on air activities some, but will be able to react instantly, without pressure, to any emergency you find yourself in.
Practice makes perfect, truly applies to Ham radio under stressful emergency conditions.
So my long winded advice is... Don't get your Ham license unless you are willing to put in the time to learn how to use it without referring to the manual.
If someone really wants to have communications ability beyond land lines and cell phones, which often Fail under emergency conditions, then for some people I recommend spending the time and effort in getting an Amateur (Ham) Radio License.
FRS radios are for local, close-by communications like inside theme parks, County Fairs and such, and have limited practicality in an emergency situation for several reasons.
But, Ham Radio, specifically the 2 Meter band, is a network with established emergency communications protocols that save lives every year all over the world, and it's all run and maintained by Volunteers!
It can also be used for non commercial, personal communications, but it's not like a cell phone which is mostly private, so anyone with a similar radio or radio scanner can listen in to your Ham radio conversations.
It's akin to talking to a friend in public or a restaurant.
Once one learns the Ham radio communication protocols, it's an amazing radio service to belong to, and if one is intellectually curious, you can follow multiple paths of interest within it, far beyond mere personal or emergency communications.
But, one has to learn and be comfortable with the Tool, because your Radio won't save you if you don't know how to use it.
For instance, changing the transmit and receive frequency during a stressful emergency, or actually knowing how long you can use it before the battery is depleted, and do you have spares, and are they kept charged?
If Not, you are back to being a part of the problem instead of the solution.
One can't be "the Hero" without planning and practicing beforehand, so learn the tool of the trade, so to speak, spend several months using and getting to know your radio.
Spend a lot of time on the air talking to other Hams, learn their call signs and the language of Ham Radio, and once you are "there" you'll be able to back off your on air activities some, but will be able to react instantly, without pressure, to any emergency you find yourself in.
Practice makes perfect, truly applies to Ham radio under stressful emergency conditions.
So my long winded advice is... Don't get your Ham license unless you are willing to put in the time to learn how to use it without referring to the manual.
> Some imported DMR radios do support AES encryption, but using it can get you in trouble if you're caught.
What would be the specific crime & punishment for this?
What would be the specific crime & punishment for this?
The Communications act asserts penalties for operating a transmitter that violates the requirements https://www.law.cornell.edu/cfr/text/47/95.313 ; in general, that would mean fines assuming that you stop the violation, but in certain cases imprisonment is an option.
Other alternative is to consider meshtastic . It's basically SMS like modem using Lora.
"Handheld" is overly constraining if range is a concern.
A radio you can carry on a bag and an antenna you can carry in another bag can work similar stations 50 miles away on VHF if you're willing to go up a tall hill on each side and elevate the antennas with telescoping poles.
Similarly for (unreliable) worldwide communication on HF (with the antenna being a roll of wire).
A luggable or car mounted radio is orders of magnitude better than anything you could handhold.
A radio you can carry on a bag and an antenna you can carry in another bag can work similar stations 50 miles away on VHF if you're willing to go up a tall hill on each side and elevate the antennas with telescoping poles.
Similarly for (unreliable) worldwide communication on HF (with the antenna being a roll of wire).
A luggable or car mounted radio is orders of magnitude better than anything you could handhold.
Likely 10 db
> It is also worth noting that many cell towers and virtually all telco central offices have backup power, so you do not necessarily lose the ability to communicate the moment the lights go out on your block.
One day in 2017, power went out in my neighborhood in San Francisco. My building's fiber (Webpass) stopped working. Shockingly, my mobile phone service (Verizon) stopped working completely. It showed 4 bars but no data would get through, not even SMS. I realized that the mobile providers are happy to provide zero disaster resilience. I expected that a local cell would refuse connections when it loses its uplinks, then handsets could connect to nearby cells or other company's networks. But no, the local Verizon cell captured my handset and provided no service.
Is there any way to blacklist a GSM cell on iOS?
One day in 2017, power went out in my neighborhood in San Francisco. My building's fiber (Webpass) stopped working. Shockingly, my mobile phone service (Verizon) stopped working completely. It showed 4 bars but no data would get through, not even SMS. I realized that the mobile providers are happy to provide zero disaster resilience. I expected that a local cell would refuse connections when it loses its uplinks, then handsets could connect to nearby cells or other company's networks. But no, the local Verizon cell captured my handset and provided no service.
Is there any way to blacklist a GSM cell on iOS?
> Is there any way to blacklist a GSM cell on iOS?
i doubt that very much but would be happy to be proven wrong.
even on custom-rom android i dont recall such capability.
i doubt that very much but would be happy to be proven wrong.
even on custom-rom android i dont recall such capability.
The artificial bandwidth and encryption limitations really reduce the use cases.
My brother is a HAM, but it is so boring. People making contact, but no content. Its basically metadata only. "Can you hear me now? Good".
It's one thing if you have another hobby it enables, like off-roading or back-country stuff. But radio for the sake of radio I do not understand.
TL;DR - I'm a huge nerd but I just can't get into amateur radio because it bores me terribly.
My brother is a HAM, but it is so boring. People making contact, but no content. Its basically metadata only. "Can you hear me now? Good".
It's one thing if you have another hobby it enables, like off-roading or back-country stuff. But radio for the sake of radio I do not understand.
TL;DR - I'm a huge nerd but I just can't get into amateur radio because it bores me terribly.
Mesh p2p networks do not scale to more than a few hundred nodes sending sparse small messages, unless you can add base stations scattered around that have a more robust power source. However, some people in many areas have generators or can use their car to power their cellphone, which could act as a base station. So why don't cellphones have an emergency mode that lets them 1) send+receive p2p text messages using the cellular radio 2) lets them relay p2p text messages if the cellphone detects that it is plugged into a power source? Seems like this could be really useful when power is out over wide areas.