[TenTec] Remote Mic / Audio for Pegasus

Mark Erbaugh mark@microenh.com
Tue, 4 Jun 2002 18:15:56 -0400


I'm still considering operating the Pegasus remotely. I would like to
operate the Pegasus (in the basement shack) from the computer desk in my
office. Since the office is a true home office (I took the deduction this
year), I don't want to install the Pegasus in the office. I will control the
Pegasus over my network (I'm a programmer and will figure out how to do
that).

However for audio, that would mean that the mic is about 25 cable feet from
the radio. I've already tried using something like NetMeeting to transmit
audio over the network but the audio quality was unacceptable. I suspect
that good quality audio cable would be sufficient, but I've been looking
into an alternative using CAT 5 cabling of which I have an abundance.

I have located manufacturer's web pages describing audio baluns that
translate audio to CAT 5 UTP, but so far haven't found a place to buy them
or a price (a consideration).  It appears that these baluns are passive
devices designed to allow the routing of line level audio via CAT 5 UTP in
home theater and similar setups. I wonder if it would work for lower levels
such as mic level?

Anyone have any comments or any suggestions on making my own audio baluns?
Would a simple 1:1 isolation transformer work? I have some modem isolation
transformers that I use when hooking up the soundcard to the radio.

The simple circuit would be to take the unbalanced microphone signal and run
it and ground to one side of the transformer. Then hook the other side of
the transformer up to a pair in the CAT 5 cable. On the other end of the
pair would be another transformer. The other side of that transformer would
go to the mic input.  Ground and the +4VDC from the mic jack would be routed
on other conductors in the CAT 5 cable.

73,
Mark