[ARC5] SCR-274N LOUD Sidetone

[David Stinson]

From: J Mcvey via ARC5
Subject: [ARC5] Voice modulation too loud in
headphones on SCR-274

My scr-274 setup uses all the correct basic parts
for local operation, including the BC-456
modulator.
However , output from the modulator ( when it is
switched in by the rx rack) will blow your ear
drums out.
I can't imagine how this could be a  normal
condition , but the circuit is unmodified.
------------------

This is the "sidetone" signal, fed from the
modulator via PL-151 (6-pin), pin 1.  In the
original installations, this signal was fed to the
aircraft intercom.  Each crew station had an
"intercom box" with its own volume control.  The
signal present on the control box and receiver
rack was intended only for testing and tuning.
One can open the lead to pin 1 and insert as much
attenuation as needed to get the signal to a
tolerable level.

73 OM DE Dave AB5S