[GreenKeys] feeding audio to TU

[Eugene Hertz]

Hello all...Transmitter is behaving better, 51J4 receiver is still dead so now I'm looking to use my harris rf-590H receiver to get my M28's on the air. Had a question.

The harris has separate LSB and USB line-level audio outputs (600 ohm adjustable from -20dBm to +10dBm).  Lets just talk about LSB for the moment. For LSB it has 3 connections called:

LSB LINE AUDIO 
LSB LINE AUDIO-CT
LSB LINE AUDIO

Looking at the circuit diagram, the audio stage of the receiver feeds the primary of a transformer. The secondary has 3 connections as stated above with the CT being "ungrounded center tap."  All three are made availabe to the rear of the receiver.

My TU is the venerable HAL ST-6 whose audio input has the shield grounded (IIRC).  So what is the best way for me to take this 3-legged audio transformer output and make it single-ended for use with the st6?

any guidance apprecated!
73
Eugene