[Yaesu] Hmmm in the audio from the FT1000D to the DX Doubler

[Rob K6RB]

Had the same problem with two FT-1000Ds and a DX Doubler. For some reason -
never did figure it out - when the two radios are connected to the Doubler,
there is an inordinate amount of hum in the Heil Pro Set phones. I tried
tracing the wires, thinking there might be a misplaced ground in the Doubler
cables, but found nothing. Even with the Doubler off, and the power removed,
the hum was there. I finally eliminated most of it by buying 1:1 audio
transformers at Radio Shack, and isolating the audio lines from the D's to
the Doubler. There is some attenuation of the audio as a result, but the hum
is now gone for all practical purposes. It is evidently an issue with the
Yaesu, because I used the Doubler with a D and an IC-751A, and the Icom's
audio was hum free! Hope that helps.

Rob K6RB