John Tetreault (WA1OKB)
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I know my APRS ht is transmitting narrow band, but I had considered that possibility and tried setting the 818v module to wide band just in case... Same result.
It truly is a mystery at this point.
Worst case, the guy who makes the module has offered to ship me 2 new ones on Monday....so if it is a case of them somehow being defective that should address it... Meanwhile I keep tinkering over the weekend.
On Fri, Mar 13, 2020, 6:33 PM Ray Wells <vk2tv@...
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?
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.