Sigtronics SPCC-2 - Manual (Page 6)

radio compatible to the FM radio you are using
with the SPCC. Then . . .
1. Set the ON/BYPASS switch to the “BYPASS”
position and connect the SPCC up to power, as
normal. Plug in the observer’s PTT switch and
headset. Do not connect the FM radio to the SPCC
at this time. (It is not necessary to connect the
A/C radios or the pilot’s headset or PTT switch for
this adjustment.) Set the observer’s XMIT SELECT
switch to “FM”, the AUTO/OFF/BOTH switch to
“AUTO”, and the AUX switch to “OFF”.
2. Set the SPCC aside for a moment. With the FM
radio disconnected from the SPCC, transmit as
normal, on the FM radio, to the remote station.
Transmit long enough so that the receiving
station can get “calibrated” to your transmission
(voice) level.
3. Connect the FM radio to the SPCC as normal with
the FM interface cable. Put on the observer’s
headset and turn the SPCC “ON”. Verify FM radio
reception. If OK, use observer’s PTT to transmit to
your receiving party. If receiving station reports
weak transmission, use the screwdriver to turn the
FM MIKE GAIN ADJ clockwise a small amount. If
they report garbled or broken transmissions, turn
the FM MIKE GAIN ADJ counterclockwise a small
amount. Repeat as necessary until the receiving
party reports that transmissions through the SPCC
sound as good or better then when the FM radio
is used separate from the SPCC. That’s all there is
to it!
The A/C Radio Mic Gain Adjustment is located to
the left of the FM radio interface connector. Again,
the A/C Mic Gain Adjustment, in most cases, will not
have to be changed from its original factory setting.
If however, your aircraft radio transmissions through
the SPCC are reported as weak or garbled, you will
need to reset this level. The adjustment procedure
is similar to that of the FM mic gain adjustment
above. You can, however, use the “BYPASS” mode
of the SPCC to aid in the adjustment. Arrange to
have someone with an aircraft radio nearby with
whom you can transmit and receive. Then, proceed
as follows:
1. Set the ON/BYPASS switch to the “BYPASS”
position and connect the unit as normal to power
and aircraft radios. Plug in the pilot’s headset and
PTT switch into the jacks on the left side of the
SPCC. (The FM radio and observer’s headsets and
PTT switches are not needed for this adjustment.)
On the pilot’s side of the SPCC, set the XMIT
SELECT switch to the “A/C” position, the AUTO/
OFF/BOTH switch to “AUTO”, and the AUX/OFF
switch to “OFF”.
2. Put on the pilot’s headset. Transmit and receive to
your nearby station, using the pilot’s PTT switch
and headset, as described in the Initial System
Check-Out section on page 8. Verify good
transmission and reception. In this mode you are
bypassing the SPCC and verifying the clarity of the
aircraft radios.
3. If radios check out OK, then turn the ON/BYPASS
switch to the “ON” position. Verify aircraft radio
reception. If OK, use the pilot’s PTT to transmit
to your receiving party. If the receiving station
reports weak transmissions, use the screwdriver
to turn the A/C MIKE GAIN ADJ clockwise a
small amount. If they report garbled or broken
transmissions, turn the A/C MIKE GAIN ADJ
counterclockwise a small amount. Repeat as
necessary until the receiving party reports that
transmissions with the SPCC turned “ON” sound
as good as that when the ON/BYPASS switch is
“BYPASS” mode.
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