Steve:
Waterproofing is easy. either the circuit board mounted in a waterproof project box with connections passing through it via hot melt glue sealed holes, or circuit board, antenna connectors, morse key, and earphones stored in a metal mint type tin, which in turn is stored in an air-tight sandwich box.
For a closed private group easiest solution is to teach everyone who will be using the equipment how to rig up the radio antenna and various other connections, and also teach them how to code and decipher simple slow morse code. In fact it does not even have to be morse code as you do not want to broadcast for all and sundry to understand. So you can invent your own dit-dal code sequences for calling and for simple messaging.
Conventional radio call signalling is CQ (seek-you) repeated many times and followed by callsign. At end of code message it is useful to have an end of message character. K is the conventional signal for this.
If you want to automate the calling process one of these would do the job:
http://wb9kzy.com/smtkeyer.htm I use one that I built many years ago and its very effective.
Code reading and display can be done by the little processor I pointed you at earlier, but the most robust and discriminating device would be the human ear and brain :-)
Powering from a car 12v system is easy.
I'm looking to set up for exactly the same purpose GR
But our geographics are a wider. I need a 60 mile range
When you start listening on the Morse code allocated sections of the amateur radio bands you might be surprised at how many people can and do still operate Morse code. The point here is that Morse code is not private. In a SHTF situation you could just use a code of your own making and then you would be sure of no idle eavesdropping.
Trying to automate everything will reduce the reliability of the system. Its doable but will be frustrating to set up and use.
(31 October 2015, 13:42)Geordie_Rob Wrote: I'm very interested in this thread but very confused at the same time. Am I right in understanding this would be a cheap way to send & receive messages over long distances? To send a message you type it in on a standard keyboard & it converts it (with purchased add on kits) to morse code & sends out as morse. Then to receive the message (with purchased add on kit) it picks up the morse message & displays it as words on LCD screen? If that's how it works, it could be very useful indeed to a lot of people.
If I've totally got it wrong though, feel free to correct me & laugh to yourself for me being so simple 
Answering this part last ( sorry)
Yes, with an antenna suitable for NVIS this sort of radio should give pretty much continuous daytime coverage from base out to 100 to 200Km. The beauty of NVIS is that the transmitted signal is received from overhead not line of sight, so getting signals over obstacles and into river valleys is viable.
The military use HF NVIS for this very reason.
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Pixie CW transceiver
