Re: [amsat-bb] introduction and request for information (APRS EMAIL)
What I want to do next is basically email myself over RF via space. I'd prefer to have an antenna that wouldn't need to track. [and] limit myself to passes over X deg (say 30) to get short ranges...
Its easy. Use any AX.25 1200 baud packet system on 145.825 MHz when the ISS comes over several tiems a day and send this packet:
URCALL>APRS,ARISS::EMAIL....:UREMAIL@WHATEVER.WHATEVER hi world this is me.
The first part is the header built by your packet modem or software showin your SENDING call, the destination address of APRS and the VIA path of ARISS.
The body of the packet must begin with :EMAIL....: Which tells APRS it is a "message format. The extra 4 dots shoule be spaces to pad the message address field out to a total of 9 characters.
Then immediately following that is the body of an APRS message. In this case, to have it become email, you have to begin the message with the FIRST "word" being the complete email address. In the example, I wrote that as UREMAIL@WHATEVER>WHATEVER
And then after a space to separate it, is your actual text of your email.
All of this is in one packet, and the sum total of the length of y our email address and the text of yoru email must fit in the APRS message size of I think it is 67 bytes.
CAVEAT: All of the above assumes the ISS is on 145.825 MHz (I think it is not. I think It is now on 437.550 MHz which requires you to track Doppler in a complicated fashion stepping up in transmit frequency while at the same time stepping down in frequency for receive during the pass.
Also it assumes the global APRS "EMAIL" engine is on line and working...
ALSO it assumes the ISS digipeater address is still working as ARISS. If not, you may have to use the actual call of RS0ISS if that is what it is.
Search for APRS EMAIL and you should be able to find something.
Bob, WB4APR
Robert Bruninga bruninga@usna.edu writes:
Its easy. Use any AX.25 1200 baud packet system on 145.825 MHz when the ISS comes over several tiems a day and send this packet:
"It's easy" followed by "use any AX.25 1200 baud packet system" makes sense to you experienced hams, but that covers a lot of new ground for me.
Right now, my only transmitter is an HT. I have successfully built at least one antenna for it for handheld use. I have not been particularly successful in using fldigi to talk to it.
I think to follow your instructions, I would need a chain something like this:
computer with ax.25 software <-> fldigi <-> HT <-> some unknown antenna
Does that sound reasonable? I assume the stock antenna will be basically worthless here, is there a suggestion about what I should use? Something non-tracking would be ideal.
There's definitely ax.25 software available to me, but I haven't explored it at all nor do I know how that might interact with fldigi. Or maybe fldigi has ax.25 built in and the computer just needs to format the message. I'll have to mess around with this part this weekend.
El 02/12/16 a las 13:12, David Rysdam escribió:
Robert Bruninga bruninga@usna.edu writes:
Its easy. Use any AX.25 1200 baud packet system on 145.825 MHz when the ISS comes over several tiems a day and send this packet:
"It's easy" followed by "use any AX.25 1200 baud packet system" makes sense to you experienced hams, but that covers a lot of new ground for me.
Right now, my only transmitter is an HT. I have successfully built at least one antenna for it for handheld use. I have not been particularly successful in using fldigi to talk to it.
I think to follow your instructions, I would need a chain something like this:
computer with ax.25 software <-> fldigi <-> HT <-> some unknown antennaDoes that sound reasonable? I assume the stock antenna will be basically worthless here, is there a suggestion about what I should use? Something non-tracking would be ideal.
Hi David,
fldigi doesn't do 1200 baud AFSK, which is the modulation that you need for the ISS and other APRS satellites. I recommend direwolf.
73,
Dani EA4GPZ.
participants (3)
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Daniel Estévez -
David Rysdam -
Robert Bruninga