KW Flashbox. Here is the damage

[W1UJR]

If you are modulating at 20 or 30 KHz this could be outside the bandpass of the matchbox. This will present a different load on the rig and maybe causing a high voltage to be generated in the network because it isn't going to the antenna. I bet you notice the swr change with modulation.

So the way to test for that would be to limit the audio passband?
Strap in a carbon mic or such?
That's an interesting point as I used to have this problem with my T-3, guess
I could have tested the theory by squashing down the audio with the EQ?

Now that I've got my old audio processing gear up from Buffalo, I'm tempted to fire up the T-3 again.

-Bruce

[WA1GFZ]

Todd,
You may have sometinng oscillating in the audio chain way off frequency or should I say very high audio frequency. Try to get someone with a SDR to monitor your audio wide band on a quiet afternoon.

[Steve - WB3HUZ]

So why would it only manifest itself 70 kHz above the resonant freq of his dipole and not 70 kHz below.

Todd,
You may have sometinng oscillating in the audio chain way off frequency or should I say very high audio frequency. Try to get someone with a SDR to monitor your audio wide band on a quiet afternoon.

[Todd, KA1KAQ]

And that's the confounding part which, as you said, we may never know. Worse is, the aerial worked fine at the previous location, same new feedline and all. I've got a feeling it has something to do with the capacitive vs inductive properties at the two ends of the band, but as Quasimodo once said, "It's just a hunch I have".

[ke7trp]

Which is why my project today is to replace the Fried loading cap in the rig.

C