Dr891 inconsistent PTT failure

I received my dr891 today and of course hooked it right up to test it out. Everything seemed to be working out great when I noticed the PTT was working inconsistently. Seemingly at random when whatever software tries to trigger the PTT it would only stay on for a second, while the software would either think it was still on, or would freeze.

After I reset everything it will work again a few times then do it again. This happens with WSJT-X, JS8Call, though Flrig or direct, Flrig, and VaraHF.

I have tried adjusting settings on both the rig and pc to no avail, and I tried both USB-C to USB-C as well as USB-A to USB-C cables.

A few notes about odd behavior, sometimes when the software freezes and I have clicked on the transmit or PTT button a few times it will “catch up” after a few seconds and trigger the PTT on and off the number of times clicked the button.

Also after I close Flrig and the 891 returns to its original settings (which is why I like to use it) for some odd reason menu setting 11-07 SSB BFO is being set to LSB instead of auto, that might just be a Flrig issue.

Any assistance would be greatly appreciated.

Cheers!
-Dax

What is the PTT method do you choose in WSJT-X?
Does this issue happen at the lowest RF power level?

PTT method in WSJT-X is CAT

This issue does happen at the lowest power level.

I also noticed now that the tune button in WSJT-X is incrementing up my frequency by 1kHz every time I push it.

That sounds like an RFI condition, though I was hoping it wouldn’t be the case at the lowest power level. For troubleshooting let’s try bypassing Digirig and connecting USB cable directly between the radio and computer. Are you able to get a reliable PTT/CAT this way?

Yes, with a direct connection I was able to get reliable PPT activation via Flrig and WJST-X

I am unsure where the RFI would be coming from but just to be safe I did add some ferrites to the USB cable just to insure that was not an issue and it did not help.

With the CAT connection through Digirig and the device manager open, do you see any changes in the listings when you run transmit cycles? E.g. serial ports dropping out and popping back up?

No changes I could see in the device manager during a transmit cycle. For both a successful PTT engagement and a failure, nothing changed.

When it comes to CAT control and PTT that comes through as a CAT command, DR-891 only plays a role of the USB hub. We know that it works since you have CAT control during the receive. Something doesn’t work right during the transmit. This still sounds like RFI scenario in absence of better explanation.

The two ways RFI can wreck havoc on the accessories is when:

  1. RF signal from the antenna nearby wirelessly induces currents in accessory cables or
  2. insufficiently balanced/chocked antenna system uses connected accessory cables as part of its counterpoise.

Different cable lengths and alignments will produce different outcomes. Reducing RF power (as long as you used the correct setting among FT-891’s many) sometimes helps to isolate the effect, but the best option is to combine the test with a dummy load.

If you are done with the troubleshooting I can exchange your Digirig to see if replacement makes any difference, please PM for arrangements.

As an additional experiment you can try DR-891’s fallback VOX method: set PTT to VOX and in the audio settings change output channel from “left” to “both”.

Ok I will do some more troubleshooting tonight and try as many different scenarios as I can manage and if I can isolate the issue to the digirig I will contact you for a replacement. Thank you for the assistance and I will let you know what I find.

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First, thank you for being willing to send me a replacement it was greatly appreciated.

As you suspected it did not fix the issue. But on the bright side I did find a serious source of RFI in my house, my wife’s grow lights and was able to mitigate that.

However my issues continue, though now I do think they might be with my radio and not the digirig. I know you asked me to test the CAT control via a direct USB connection to the PC and I said it worked, and it did in testing. But when I tried to actually use it as a solution I ran into the same issues, it just took a little longer to manifest.

I know this isn’t digirig issue anymore but if anyone has any advice on how to continue troubleshooting I would be very grateful as I am out of ideas.

what is the computer you’re using?

big ol’ desktop/tower or gaming laptop or maybe a ultralight notebook?

kb0wlf

Thus far I have tried four PCs, one gaming desktop and one gaming laptop, then I pulled an old work desktop (win 10) out of the closet and tried that, lastly I got a lightweight laptop just for radio stuff and the issue persisted on all four.

Another thing of note, I removed the 1 foot RG45 extension I had added to the mic so I could easily remove the mic and I thought that solved the issue, I successfully used Winlink but when I tried FT8 the tune button seemed to work fine but then I tried to make a contact and it failed again.

Also of note I am not using FLrig anymore.

qsl
that was my only hope of helping.
i’ve just no experience with modern yaesu.

i have several very handy laptop/notebooks that absolutely hate operating a radio.
the usb ports just simply ‘freak out’ and lose cat connection + hang the ptt when the radio keys at any power level.

sorry i couldn’t help
good luck

kb0wlf

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Were you getting decodes of the received traffic on FT8?

I am and it seems to be working just fine, I even started a QSO and got though most of it until I went to send 73s and it failed and would not send even though I tried several times over a few cycles. It seems that I needed to restart WJST-X to get it to PTT successfully again. But I did stop trying to make contacts after that.

What do you use for the antenna?
It may be better to use some RFI choking there.

At the shack I am running a Yaesu Y-30 folded dipole and it is choked with LDG choke at its feed point. Though I did try a Gabil vertical in my backyard as well.

So you are still thinking it could be an RFI issue even if I bypass the Digirig for CAT control with a direct USB connection? Hmm

I need to get out to a park and get away from all my home’s RFI and see if I still have issues there.

I doubt other sources can wirelessly induce enough noise to disrupt the USB connection. Wired RF transmitter has much more impact on this.

The biggest indicator of RFI is that everything works without issues until you transmit.

Good to know, thank you.

I will continue to test, I appreciate your continued support!

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