audio circuits through contacts 10
(2) Speaker audio is applied to the front
and 19 of relay K802. On transmit,
panel AUDIO jacks through a vol-
headset audio for sidetone at a re-
ume control that consists of fixed
duced level is tapped off terminal
8 of T802 through contacts 11 and 19
R714 (the front section of the VOL-
o f relay K802. Resistor R615 at-
UME control), and rf filter FL705.
tenuates the audio applied to the
Speaker audio is applied to Radio
AN/GRC-3 through -8 communica-
Set Control C-1439/U through fil-
tions equipment to a fixed level of
ter FL3 and terminal F of plug P1.
approximately 50 milliwatts (mw).
Interunit audio output connections
T h e fixed-level audio is applied
are shown for both Radio Set AN/
through rf filter FL26 and plug P1.
VRC-24 and AN/TRC-68. Radio
(2) Resistor R601 attenuates the head-
S e t Control C-1439/U audio cir-
set audio applied to the front panel
cuits are described in para-
AUDIO jacks. Front panel headset
audio level is controlled by fixed
b. Headset Audio.
r e s i s t o r R4 and variable resistor
R710 (ganged to R714). Front panel
(1) On receive, headset audio is tapped
headset audio is applied to termi-
off terminal 7 of the secondary of
nals A of J702 and J703, in parallel,
output transformer T802 and ap-
through rf filter FL701.
plied to the headset and fixed-level