Hi Oldie,
I recently set up Winlink, and Vara FM with Digirig, so let me share some thoughts.
Before all else, make sure audio from your radio is reaching VARA FM and the VU meter shows some level over zero, ideally when all level are set, the VU would be in the middle 3rd of the dial on a quiet band with no stations heard, but anywhere in the green should work (VU is the sound level-in to VARA FM)
For audio-in from your radio:
Windows (my assumption)>Sound>Recording shows “Digirig” (mine says Mic In) as the default.
Right click Digirig (Default Device)>Properties>Levels, and set to some initial value (mine is 37)
VARAFM>Settings>SoundCard> Device Input = Digirig
FT-818, I am not familiar with, but do whatever setup you need to for audio line-out to whatever port your Digirig audio cable is plugged into. (Ideally the FT-818 audio line out will be non-equalized, and not changed by volume or squelch controls) If the FT-818 allows level -out control, set it mid-range for now. If it does not allow level control out (a fixed level like my radio) it is still ok; you will just have to adjust the level via Windows device levels. With radio on, FM mode, empty band, VARA FM on, the VU meter should be showing some level. If not, work on it until it does before the rest of the set up.
One (remote) possibility: the attenuator (ATT) pad on the Digirig PC board has been cut, which will drop the sound level-in by 20dB. If you are getting a low but non zero VU level with radio audio line out and Windows Mic levels both really high, check the ATT pads (I had to use a magnifying glass)
(Input Attenuator: Digirig Mobile Rev 1.9 – digirig)
CAT Control:
Not knowing the FT-818, I can’t comment, but from the thread with Constrained, it seems like your radio is keying when you are expecting it, so I’ll assume you have it set.
TX audio out:
Windows >Sound>Playback shows Digirig (mine says Spkr Out). Make sure Digirig IS NOT the Default Device.
(System speakers or some computer device should be default Device. This is where computer sounds go and you don’t want them to be transmitter by your radio. I have been told some Windows versions decide on there own to reassign Default Device when devices are unplugged and re-plugged, so watch your system.)
Right click Digirig (Spkr Out)>Properties>Levels>Speakers and set to some initial value (mine is 37)
Right click Digirig (Spkr Out)>Properties>Enhancements and disable all enhancements
Try a Winlink session and listen to your HT for anything audio (warble, hash, digital noise) that is obviously coincident with your radio transmitting. If you get a dead FM carrier then TX audio is not set up correctly yet.
I like Constrained’s suggestion of plugging headphones (something) into the audio port of the Digirig while VARA FM is outputting audio to confirm it is there. This is different than using your computer audio to listen to your radio’s receive audio (I thought that is what you tried).
You can use the VARAFM>Settings>SoundCard> Tune button. It keys the radio via CAT and sends audio. Try the drive level midrange at this point.
Auto Tune:
Tune your radio to the nearby Winlink gateway frequency
VARAFM>Settings>SoundCard> and set your level high, maybe -6dB, then the Auto Tune button.
Here is a video I found helpful: Setting Up VARA FM on FT-65R - #5 by K0TX
Auto Tune will progressively reduce your drive level for you to the best level for that gateway.
Make note of where it ends up. Mine is -21dB.
About FM and other modes:
My radio only does FM, so your FT-818 in FM mode should work. It’s all about receive audio filtering; you don’t want any. Use FM (because that’s the mode used on 2m gateways), but read your radio manual about the different settings and set them up for the least receive audio filtering or audio shaping you can.
Lastly – Uncommon weirdness to watch for:
After successfully achieving an “Approved” VARA FM calibration and VARA FM gateway ping with my Digirig, I kept getting “Failure to connect” from a local Winlink Gateway which I had used many times and right up to the swap-in of my Digirig in place of my prior TNC. I then successfully connected with a different gateway confirming my new set up (JOY!). Looking at the Winlink gateway listing and exchanging messaged with the owner, it appears that his gateway does not have the latest VARA FM software version. Apparently the different versions of software made a difference with Digirig but not the KPC-3 Plus. Until the owner upgrades VARA FM (and maybe more), I won’t be able to retry that gateway.
I hope some of this helps. I am good in QRZ if you want specifics of my settings.
-Jeff AJ6LG