FSG 70/FSG 71M
O
PERATION
M
ANUAL
Page
4 - 4
Reprint July 1998
W. Dittel GmbH
When operating from aircraft's power system
Blinking frequency display:
The aircraft's power system must soon be
investigated!
When operating from 28 V aircraft power system
Blinking frequency display:
Check voltage regulator and aircraft's power system.
4.6
Emergency Operation
In an emergency case, the unit can also be operated with supply voltages down to 9.7
Volts. The audio output and transmitting output are of course reduced.
Batteries must always be recharged immediately after emergency operation because
extensive discharging incurs the risk of deterioration and permanent damage - this risk
is increased if a discharged battery is also stored in that state.
4.7
Squelch Function (SQ)
With the left toggle switch in the "SQ" position (normal operation), the automatic
squelch circuit of the unit, is active. This disables the audio amplifier when the receiver
has no signal or one which is too weak. Signals stronger than the threshold (approx.
1µV) enable the audio amplifier and are therefore reproduced in the
headphones/loudspeaker; annoying VHF noise is thereby suppressed. Also,
considerable power is saved. If, however, very weak signals are to be received (e.g., a
glider landing far from base), then the SQ toggle switch is placed in the down position.
This permits noise during pauses, but weak signals of marginal strength are no longer
suppressed, and the full reception range is available.
4.8
Intercommunication (IC)
1. Turn on IC mode with IC switch (refer to Fig. 3-7/3-8).
2. Intercommunication is performed via microphone and headphone.
3. Pressing the push-to-talk button activates the transmitter as usual - turning off the
IC mode is not required.
4. After releasing the push-to-talk button intercom operation is re-enabled.
4.9
Audio External
Via the AF-Ext. input a second or third radio (or NAV-receiver, E-Variometer) can be
connected to the transceiver. When wired for this purpose, the volume of the external
receivers is/are to be set so the signals can be understood, and distinguished one from
another.
The VOL control of the
FSG 70/FSG 71M
affects not the volume of the external units,
and vice versa.
