Operating instructions

b. IMMEDIATELY rotate P.A. TUNE control for
maximum meter reading. -nus is the critical
"resonating" adjustment which must be done
quickly to preserve P.A tube life.
NOTE
The Transceiver will not modulate with the
Function Switch in the CAL position.
Rotate P .A. LOAD control for maximum.
AM TRANSMITTER TUNING
d. Re-adjust P.A. TUNE control for maximum. This
adjustment should be repeated each time the P.A.
load control is adjusted.
CD Tune the transmitter to full output 3S you would fo,r
SSB transmitter tuning.
@ Rotate MIC. GAIN control to' full CCW (minimum)
position.
NOTE
0 Place the SIDEBAND SELECTOR switch in the AM
REC. position.
With the Meter switch in the S-Meter position,
and the Function Switch in the TUNE-CW posi-
tion, the meter is reading RELA TIVE OUTPUT.
This RELATNE OUTPUT reading has no rela-
tionship with the true output of the trans-
mitter. To obtain a true indication of the trans-
mitter output, place .tli.\; -lJeter switch i.. P.A
CATHODE, and rotate the Function Switch to
TUNE-CW. Normally, when the transmitter is
in resonance. the meter reading should be
approximately 300 ma. or higher. With high
line voltage and new tubes it may read as high
as 350 ma. Note that the 1011 B operates at re-
duced power in the TUNE-CW position. The
P.A. cathode bias resistor, R-406, is in the cir-
cuit during TUNE and CW operation. In voice
mode, the bias resistor is shorted out, and the
1011B operates at full P.E.P. input rating.
0 Place the Meter Switch in the P.A. CATHODE
position.
<D "'With the microphone press-to-talk switch pressed,
rotate the CARRIER INSERTION control until
cathode current is approximately 125 ma.
@ While talking in a normal tone of voice into the
microphone, increase the MIC. GAIN control setting
until the meter barely kicks upward. This setting will
result in excellent AM transmissions.
CW TRANSMI1TER TUNING/OPERATION
CD Tune the transmitter to full output as you would for
SSB transmitter tuning.
<y Insert a CW key in the Key Jack on the rear panel of
the transceiver.
@ The preceding steps complete the Transmitter Tuning
procedure for SSB. Return the Function Switch to
the REC. position.
0 In CW operation, it is necessary to switch the Func-
tion Switch to the TUNE-CW position \¥hen trans-
mitting, and back to the REC. position while receiving.
VOICE TRANSMISSION (SSB)
@ While receiving, the carrier oscillator frequency is
located 300 cycles outside the passband of the crystal
lattice filter, thus providing a single heterodyne note,
or "single signal" for CW reception. When transmit.
ting in CW mode, the carrier frequency- is moved
approximately 800 cycles higher, placing it well in-
side the passband. This frequency shift is termed
"Off-set CW transmit frequency", and avoids the
problems encountered when the receive and transmit
frequency are exactly the same. This is desirable for
voice communication, of course, but when using the
CW Keying mode the receiver must be tuned off fre.
quency several hundred cycles in order to hear an
audio beat. By providing this shift automatically CW
operation is greatly simplified.
After tuning up as outlined above, switch the Function
Switch to the REC. position. Place the Meter Switch in the
P.A Cathode position. Press the microphone press-to-talk
switch, and while speaking into the microphone, slowly
rotate the MIC. GAIN control until occasional peak read-
ings of 100 to 125 ma. are obtained. With most micro-
phones, the MIC. GAIN control will be set between 9 and
12 o'clock, but it may vary considerably. The ALC circuit
will help .limit cathode current, but turning the MIc. GAIN
up too high will still produce flat-topping and spurious sig-
nals, so it is important to hold it down. The meter is quite
heavily damped, and its reading with average voice modula-
tion may not look very impressive, but the voice peaks are
going well over the 260 watt input power rating of your
Sil tronix transceiver.
8
r""-_,. ,