The rig “chatters” between Tx and Rx, kinda like as if one was quickly feathering the PTT button on a handheld mic. But this happens only when all of the following are true:
radio is in DIG mode; and,
the Digirig is plugged into the radio; and,
an antenna is connected.
No problem in voice modes; no problem when Digirig not plugged in; no problems with a dummy load.
What tests would you suggest for diagnosing what part of the Digirig (unit or cables) is causing the problem?
There is no problem when using dummy load instead of antenna. The problem only arises when connected to an antenna. However, the antenna is resonant (not an SWR problem) and the ferrites and balun seem to make no difference (likely not a common mode problem).
So, I’m still convinced my Digirig (or one of its cables) has given up the ghost.
For what it’s worth, the problem started when I was trying to get into a Winlink gateway. I hadn’t had any success, tried a different gateway, and VARA was “knocking on the door” of a second gateway. About 5 “knocks” in, the rig started this “chattering” thing. I’ve been happily using this Digirig with a number of different softwares (Winlink, WSJT-X, JS8call) for about a year.
I didn’t try activating an attenuator because it made no sense to me that a device that had been working properly suddenly would stop working.
So I bought another digirig.
Using the second digirig, I had been using it for about a month (did 17 POTA activations with it!) , and was using it yesterday for about 2 hours, when–it happened again. Suddenly, my transceiver started “chattering”.
Again same setup as last time: Windows 10 computer running WSJT-X, TX-500 rig powered by battery, EFHW antenna (SWR<1.5), with balun on coax feedline.
What is happening that it would suddenly “crap out” like that?
the digirig i have here has maybe a little over 100 hours on it.
still running fine.
android phone or evolve maestro notebook.
do you have any choking on your feedline?
only thing i could think of is common mode finding a path to ground through the digirig if it is dying on you.
since the ‘symptom’ is tx/rx relay chattering, makes sense that something is upsetting the switch to ground ptt circuit somewhere.
fairly short path, electrically speaking, from the radio ptt to the digirig ptt ‘switch’.
I’ve been using one since Dec 2022. My usage is about 15 Winlink messages per week, plus 1 - 4 hours of fldigi per week.
When I was starting out, I was switching back and forth between an HT and a mobile for Vara FM on VHF, and a portable HF rig for Vara HF and fldigi. During that time I made lots of mistakes with cables, chokes, unplugging and settings which I would call abusive for the Digirig, but it has continued working to now 8/24.
TX-500 config provides 3.3V from Digirig to power radio’s opto-isolators. This power comes from serial chip (CP2102) which also powers the USB hub. There is resettable fuse on that line (20mA) but if you hit it hard with a quick surge I imagine you can take the chip out.
I don’t get a lot of service requests from TX-500 users so this issue is uncommon, but maybe conditions line up just right in your case for this to cause the damage. Anyway, please PM for the repair arrangements. I can take care of both of your units.
