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579 points todsacerdoti | 2 comments | | HN request time: 0.805s | source
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nunobrito ◴[] No.44287588[source]
OK but kind of outdated and incomplete. Meshcore is largely competing with Meshtastic nowadays: https://meshcore.co.uk/

To remember: LoRa only permits small text messages. Don't even think about images, voice nor binary files (I mean it).

Another option is APRS using satellite connections through a cheap chinese walkie-talkie (Quangsheng UV-K5) for 20 euros to send text messages.

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ajsnigrutin ◴[] No.44287842[source]
The problem with lora (and APRS over satellite... well, even ground APRS) is, that the bandwidth is very limited and usually only for "one person at a time", so while meshtastic/meshcore might be fine for tens of stations and a few users chatting, once those numbers get higher, the routing/signalization uses up most of the bandwidth, and many people sending messages at the same time makes the whole system very unreliable.

APRS is a bit better, because it requires ham licences and (usually) a bit more expensive equipment, but with "SmartBeaconing" and just a few hams, you get collisions (multiple people transmitting at the same time, effectively jamming eachother).

Reddit is usually full of preppers and other idiots buying these cheap chinese radios, usually without any knowledge and licences (that are needed to use them), and in turn they know nothing about actual use of those devices.... simplex range in urban environment is measured in hundreds of meters or maybe one or two large buildings between radioss, and repeaters will be in use by actual emergency servics and not really usable for any kind of "private use".

tldr: get a few books, a pack of cards, wait it out, not so long ago being unreachable away from home was the norm, and we managed.

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nunobrito ◴[] No.44287901[source]
Please stop with the FUD.

Portugal was for 24 hours without electricity. LoRa networks were jammed and non-operational because the bandwidth is limited. APRS kept working.

It is far better to have a walkie-talkie that you can use as PMR on the 446 range and use for satellite text messages than an expensive toy that very few use.

And as you also know: You do NOT require a radio license when operating under emergency situations, which is the context on this case.

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ajsnigrutin ◴[] No.44287944[source]
> And as you also know: You do NOT require a radio license when operating under emergency situations, which is the context on this case.

In portugal? Yes, you need one. Probably in every other EU country too

In USA too.

I have no idea where people got the myth of not needing a licence in emergencies, probably due to not reading the actual rules.

Also, you cannot use the same device for PMR and ham radio bands, the PMR device needs to be certified for PMR use, that means that it can only transmit on pmr frequencies and nowhere else. Other devices (eg. ham radio) cannot be used on PMR frequencies.

It's not FUD, it's regulation which exists for good reason, because in cases of actual emergencies, trained ham operators can assist actual emergency services with communication, and that's impossible if every idiot with a baofeng jams the channels.

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nunobrito ◴[] No.44287979[source]
Again with FUD.

In Portugal you are legally permitted to use channel 9 (27.065 MHz) in addition to the PMR channels. The hard line has always been on public safety bands. From a long time cooperation with the authorities (especially around the Azores) there was always an informal permission for that kind of usage across boats and islands because communication is difficult there.

Last but not least: taking the radio license exam is NOT a drama. Anyone can apply and get the radio license when they are serious into this topic.

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ajsnigrutin ◴[] No.44288001[source]
What fud?

Channel 9 is a CB channel, and neither quanshengs nor baofengs work on those frequencies at all, but you need a certified/type-accepted CB radio to use on that frequency.

Same with PMR, you need a PMR radio to use on pmr frequencies.

It's not FUD, it's just hardware limits and regulation.

Yes, 12yo kids can get an amateur radio licence, it's easy, but you still need a licence to transmit on ham bands, and you still cannot legally use a baofeng (except the few pmr models) or a quansheng on PMR frequencies, those radios don't transmit on cb freqencies at all, and there are no legal "you don't need a licence in an emergency" exceptions.

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harvey9 ◴[] No.44288226[source]
I have a ham radio and still not got around to getting my license. I never transmit on it now but in a proper crisis I am not going to worry about being prosecuted by the radio authority.
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misteriji2 ◴[] No.44288289[source]
Your neighbor has access to a car, but still hasn't got around to get his drivers licence. In a proper crisis, he'll google "how to drive a car?" and "what does the third pedal do in a car?", and won't worry about being prosecuted by the driving authority.

You will in turn have to share the road with him in the same way as other radio amateurs (and possibly rescue services) will have to share the spectrum with you. You transmitting on a repeaters input frequency without a subtone set will in turn jam the repeater (PLL is before the TSQL) will make communications impossible in the same way as your neigbor stuck in the middle of the road with a burnt clutch will make driving impossible for others.

But hey, stay lazy, don't get a licence, i'm sure you'll be able to figure it all out fast when you're knee deep in flood waters.

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nunobrito ◴[] No.44288874[source]
You don't need a radio license to receive radio messages, that is valid also for satellite messages received on walkie-talkies.

This fact alone is incredibly important to at the very minimum known what the heck is going on. Suddenly you have a cheap device in your hands that can receive updates relevant to survivors and victims.

In Portugal exist the 3-3-3 plans for anyone to practice using a radio. These are regular-weekly sessions with a lot of people joining.

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1. misteriji2 ◴[] No.44289914[source]
But who will send messages to you? Including satellite messages?

In most countries emergency services have moved over to tetra or dmr, with encryption, and all the public related info is broadcasted on "normal" broadcast fm, where you need a normal fm radio, not a ham transciever.

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2. nunobrito ◴[] No.44291954[source]
That is a question you can answer yourself when trying it out.

In Portugal +90% of tetra stopped working. DMR only locally.

Satellite APRS continued working. Who will listen? Well, those from north to south on the country were listening. More important, they were listening who was still active because those were the stations running with their own energy because even FM stations started to go down quickly as the generators ran out of fuel.

Had the blackdown lasted a week, those with a 20 euros walkie-talkies would very likely be the only ones still capable of +50 km distance communications and +1700 km reach using satellite APRS text messages.

Try to see from it from that perspective. You really won't have electricity nor cellphone coverage and not even FM in such scenario.. It's all gone.

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