Audio input level too high with Kenwood TM-V71A, Windows 10, VARA FM

Hello all,

I tried a cheap laptop running Windows 10 with VARA FM Wide and an attenuated Digrig (v1.9) plugged into the DIN port on my V71A today using the Digirig cable with a green DIN plug). The VARA FM VU meter was pegged to the right even with the audio input (mic) set to 20% in the Windows sound control. Unfortunately the sound control only has a resolution of 20%.

Any advice? Would replacing the 100k attenuating resistor with something larger help?

Regards and thanks in advance

Please check Digirig’s recording device settings and make sure the AGC is unchecked.
If that doesn’t work, please check the attenuator pads with the continuity tester to make sure they are not shorted.

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Thank you! You taught me a humbling lesson. The AGC bit me in the rear end!

I was using the Digirig with another radio recently and all was okay. Today, I shifted to the USB port on the other side of my computer since I had a GPS antenna attached to the USB port that I usually connect the Digirig to. It just so happens that I tried using the Kenwood TM-V71A today for the first time too. I made the rookie mistake of being suckered into focussing on the big thing when it’s often the little details that trips one up.

Much appreciated,


Same thing happened to me!


This should probably be pinned somewhere. It just bit me in the ass today as well.

It’s an easy fix if you know what to look for. I won’t forget again. :slight_smile:

73 de AG7TX

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I agree! Thanks for emphasizing this.

But who expects a software update or a driver installation to reset this? I think that is what was happening to me. Now I always check.

73 Constrainted

I seem to be having a similar issue where audio input is showing about -3 dB to -5 dB instead of the desired -20 dB or so.

The setup is:
Windows 11 on a Dell Inspiron 7630
Alinco DR135 with a home-built cable to the 9600 packet connector on the rear.
COM port PTT

I’ve checked:

AGC = unticked
Microphone level = 0%
Attenuator jumper is open (checked with two different DMMs and visually with a stereoscope).

VARA FM gives me reasonable pings and autotune settings, but it just seems a bit high.

Any other suggestions? Maybe a series resistor inside the DE-9 connector on the audio-in from the radio to the Digirig?

Thanks & 73,

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Congratulations on getting Vara FM working despite the level issues.

In the discussion above, the AGC was being set without the action of the sysadmin and needed to be unset.

In your case, since the AGC is unset, and microphone level is 0, the high input level may be lowered with the input attenuator on the Digirig 1.9:

Digirig Mobile Rev 1.9 – digirig

which will adjust the input level -20dB. This requires opening the Digirig and cutting or soldering. ( I am not an expert in the Kenwood TM-V71A, but is there any way to reduce the level in the radio? I do not know about adjusting the level with resistors in the cable assembly, either.)

73 Constrainted

Thanks 73 C.
I looked at the DR135 schematic and service manual. There are no adjustments within the radio.
I already cut the jumper on the Digirig. I also tried adding 20K ohms (what I had on hand) in series with the input inside the DE-9. There is a slight improvement, so I’ll need to find a 100K resistor (total 200K in series) to bring it down to a reasonable level.


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