Re: Solar APRS digipeater #networking

Ray Wells


Somebody else touched on deviation, and what you described is typical of the signal being over deviated for the rx module. Could it be that the module is configured for narrow band (nominally 2.5kHz) rx while your test tx is sending wideband (nominally 5kHz) deviation? That you can hear a voice modulated signal points to an audio level problem for packet audio. Can you reduce the audio level going to the HT? Do you have an oscilloscope so you can look at the audio going into the HT?

Ray vk2tv

On 14/3/20 9:01 am, John Tetreault (WA1OKB) wrote:
*no, you're misunderstand.... Transmitting works fine... I can send successful APRS packets with this module all day, no problem.
Its on the RECEIVE side that I'm having trouble... The module has squelch levels of 0-8.  I've tried with 0 (wide open, no squelch) and the lowest setting of 1 with the same result either way.

So, what happens... For testing purposes, I connected a small amplified speaker into the 818v modules audio out port.... Now, if I key up my HT and talk, my voice is heard loud and clear coming out of the 818v receive speaker.... If I send an APRS packet from my HT.... You can hear the open carrier begin.... As soon as the APRS data "squawk" begins... Receive mutes itself... And unmutes as soon as the APRS pack is done.

It has an LED that lights when squelch is open...and I can watch it, light comes on as soon as the HT starts transmitting, and I can hear the open carrier on the receive speaker.. At the split second the packet data begins light goes off, and no audio out of the receive speaker, once the packet data ends the light comes back on, and I again hear the open carrier until the HT transmission ends and the light goes off... So the receiver is fine with voice, but as soon as an APRS data packet comes over it just decides, "nope, I don't want to listen to that" and mutes itself.

Now... Oddly enough, if I try this same test with an 818U UHF module with a squelch value of 1. (so same exact settings just different band)  it works perfectly.... No self muting at all.... and Direwolf receives and decodes the packet.

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