On Mon, 24 Sep 2007 13:10:39 -0400, Vinnie S.
wrote:

|Got a hold of a gorgeous Robyn T-240D Yellowbird which needs repair on the
|receive. I have question regard microphone wiring.
|
|I have an amplified Astatic D-104 with the older T-UG8 stand. The Astatic manual
|says to use a .01 cap in line with the white wire, and to use High impedance mic
|only, which I assume it is.
|
|The Gemtronics GTX-5000 (which I thought was thew same radio), does not require
|it. Am I missing something?
|
|Vinnie S.
|
|------------------

I am not really familiar with either radios. Without seeing the input
circuit my first inclination is to do a DC block and secondly to do
some simple form of impedance matching.

As for the second radio not requireing the cap, that could be due to
the radio not being manufactured at the time the T-UG8 stand was made
so that Astatic did not know of it. Also the mic input maybe a bit
different despite the rest of the radio circuits being identical. A
lot of radios were made to work with dynamic mics and required low
impedance inputs. The D-104 line works well with tube rigs which are
usually high input impedance.

james