[TenTec] Balanced vs. unbalanced mic

[Dudley Hurry]

Mark,

Let me make a suggestion, Use a GOOD quality commercial audio cable with a
shield..  Since TenTec uses a floating audio (audio hot and ground are above
ground) connect the white to audio hot, black to audio ground, and ground
the sheild at the radio end ONLY..   Leave the sheild open at the mike end.
This should work, with no RF or added noise..  Works for me..

Thanks and 73's,
Dudley
WA5QPZ
jhurry@austin.rr.com


----- Original Message -----
From: "Mark Erbaugh" <mark@microenh.com>
To: <tentec@contesting.com>
Sent: Wednesday, April 24, 2002 8:21 AM
Subject: [TenTec] Balanced vs. unbalanced mic


> I'm still considering remote (20+ feet) operation of my Pegasus. Based on
> some previous replies on this forum, Canare Star Quad cable was
recommended
> for running mic level audio, so as to minimize interference being picked
up
> by the long cable run.  I've researched this and found that the reason for
> Star Quad cable's noise immunity is that when used for balanced audio, the
> noise pickup on each pair of  + and - leads tends to cancel, in much the
> same way as how coax keeps the signal in and noise out.
>
> I also discovered that with a balanced signal, similar results can be
> obtained using ordinary CAT 5 network cable. I happen to have a lot of CAT
5
> cable so that would be my preference.
>
> However, I believe to get the noise immunity, I must somehow convert the
> unbalanced mic output (TT 705) to balanced, run through the cable and then
> unbalance it for input to the Pegasus. I did find a simple schematic for
> feeding a balanced source into an unbalanced input. I wonder if there are
> similar circuits for converting  the other way?
>
> Any suggestions?
>
> Thanks and 73,
> Mark
>
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