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

[David Jordan]

The audio on the Yaesu floats.  If you provide a true ground you'll get 
AC hum.  The transformer provides some isolation. I have an interface 
circuit that will provide
you a better method to match the inputs and it's simple to construct.  
I'll email you direct with the attachement of the circuit diagram.

Good luck,
dave
wa3gin

Rob K6RB wrote:

>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
>
>
>_______________________________________________
>Yaesu mailing list
>Yaesu at contesting.com
>http://lists.contesting.com/mailman/listinfo/yaesu
>
>  
>