I wrote this a Dec 02 2009 But all the info still is the same. I decided to repost it since some members have been playing with it again and also using psk31 and the interface is the same for both. Remember some of the Freqs (on HF) that are being used for EasyPal are in the Extra part of the band so make sure you can transmit there before you do! Or the gentalmen there will be sure to remind you!
Some of the club members have been hanging out on simplex frequency 147.430 (we call it the "tom tom" freq) and using it to ragchew on and we have been using 146.460 to play with some digital modes including DRM (Digital Radio Mondiale) sending pictures and there seemed to be some interest, someone said we should write something about it on the website, so here again is another attempt by me at writing a article..

 DRM is the digital version of slow scan tv (sstv) but being digital, the pictures will be received just as good as they were sent, unlike sstv. You can use DRM to send and receive files and pictures (pictures are what we are sending) it uses compression, has error checking and if you don't get all the file, you can do what is called a "BSR" which sends a request to anyone, that has received the picture, they can issue a "FIX" which sends the parts that you didn't receive without having to send the whole file again. So if you didn't receive all the segments from the original sender, cause of conditions of the band or you just have a weak signal, someone that is closer or has a better signal, that did receive the picture can retransmit the missed segments to you.

 The program that we have been using is Easypal. If you are just interested in just decoding what others are sending it can be very simple setup. It can be as easy as downloading and installing Easypal and laying a microphone from computer and sitting it on top of your radio speaker and adjusting the volumes of your radio and microphone of the computer, this is the way my father does it and it works pretty darn good. Only thing using this method you can't request a BSR, so you will miss some of the pictures being sent. You can also make or buy a cable that can go from your radio's speaker output to your computers sound input (either the line level input or mic input) you just need to be careful you could damage your sound card if you use to much input volume. 
 But a better way of doing it is by using a interface like the signalink (which is what I have been using Thanks W4EBZ) or a rigblaster or here is a great web page on building your own and they all can be used for DRM, RTTY, PSK, and SSTV. With these methods it is possible to send pictures and send BSR request. 

 Like I said we have been using 146.460 to send pictures back and forth but we also use it on the HF bands (we receive more that transmit on HF) some of the frequencys that you can find DRM on are 

3.713 LSB
7.173 LSB
14.233 USB
18.1625 USB

 When they send the picture they will give a little story then they will transmit the picture and you will get a laugh out of it. But I can see this mode being real helpful in a emergency type of situation. This is just a very general overview of DRM and were we are transmitting if you have any question jump on 147.430 and ask any of us a question we will try to help you out any way we can. 73 KC8DAX