DR-891 and Winlink

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1

The new DR-891 works great on FT-8, but the transmit relay chatters when trying to communicate in Winlink. Any thoughts?

2

There is no relay in the DR-891 that I am aware of. This maybe the relay for the output stage of your radio. The turnaround time between TX and RX is demanding for Vara FM and Vara HF. What radio and mode are you using?

73 Constrainted

3

It is the output stage of the radio that is chattering. I’m using a FT-891 with the new DR-891 Digirig. FT-8 transmits fine no relay chatter. It’s only happening in Winlink. CAT control is working because it changes mode just fine. When I use tune in VARA no chatter. It’s just weird.

4

Thanks for the additional information. Vara FM and Vara HF client and node negotiate the connection and exchange verification information while passing the payloads. The output relays “work hard” and that may sound like chatter, but you can confirm what’s going on by looking at the Vara displays. If the relays go into oscillation and chatter without indication of ACKS and NACKS on the Vara display, then that’s a chatter problem. Does that make sense? Vara’s closed source, and largely undocumented, otherwise I would point you to the explanatory documents.

I have been TX/RX Winlink Vara HF and Vara FM messages at a rate of ~15/week during the last year, and all relays are still working.

73 Constrainted

5

i’m not well versed with the dr-891 but if i remember correctly, that one can use gpio or ‘audio’ to ptt the radio yes?

if you’re using ‘audio’, the level is going to be much different than the 2 tone audio for ft-8.

vara sounds like pink noise most of the time and also has it’s own audio drive ‘level control’.

just a thought i had, please disregard if you’re using gpio for ptt.

also, as constrainted said, winlink is rapid fire back and forth on the connection and request stage. obviously transfer several dozen K will get some longer tx/rx cycles but nowhere near 15 second cycles of ft-8

good luck
kb0wlf

6

I condition is abnormal, a remote possibility is RFI triggering VOX circuit in DR-891. Does the issue persist when radio is set to the minimum RF power?

I would expect something like that locking PTT rather than causing the chatter.
VOX and GPIO PTT methods can be disabled by cutting corresponding traces between pads:

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7

I was having the same issue and found a fix that worked for me. In the VARA-HF soundcard settings, I tweaked the drive level while the radio was transmitting. It was “choppy” until I got to about -14db and then, it held a steady transmit. Hope this helps.

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