Swann MARK II - Tuning Procedures; Initial Tuning Setup; Tuning Cautions

BLACK WIRE To
my te BRASS PRONG
r GREEN WIRE TO
<— TINNED PRONG
(NEUTRAL)
=P —~—e WHITE WIRE To
BRASS PRONG
3 COND. POWER LINE CABLE ied
From MARK IL PowER suppLy
‘ COMMON TYPE,
ZIOVAC PLUS
SLACK WIRE
am AX TO FLAT PRONG
WHITE WIRE
TO FLAT PRONG
)
S_ GREEN WIRE TO
GROUND PIN
3 COND. POWER LINE
CABLE FROM MARK IT
POWER SUPPLY.
COMMON TYPE 117 VAC
PLUG WITH GROUND PIN.
FIG. 2 AC PLUG CONNECTIONS
For 117 volt operation of the Mark II, it will be nec-
essary to change jumpers on the terminal strip in the
power supply. Remove the power supply cabinet,
and refer to Fig. 3 for jumper changes. Replace the
two 20 amp. line fuses with 30 amps. Connect the
black and white power cord wires to 117 volts, and
connect the green wire to neutral ground.
JUMPERS FOR 230 VOLT INPUT.
(AS SHIPPED FROM FACTORY)
WARNING: DISCONNECT INPUT POWER CORD
BEFORE REMOVING CABINET.
FIG. 3. POWER SUPPLY, TOP VIEW.
NOTE: When the Mark II is operated with 117
volt AC input, current drain will exceed most out-
let ratings, particularly in the full power "SSB"
position. It may be necessary to operate only
in the "TUNE-CW'" position in order to reduce
power drain and thus keep the house circuit
breaker from kicking out. If it is necessary to
operate the Mark II on 117 volts, try to run it
on a separate circuit, and if possible on the oppo-
site side of the primary house circuit from the
side used for the rest of the station. Always use
230 volts for the Mark II whenever possible.
JUMPERS FOR 117 VOLT INPUT
TUNING INSTRUCTIONS
1. Always tune the exciter or transceiver first, with
the Mark II turned OFF. Exciter output will be
shunted around the linear amplifier by the inter-
nal relay, and will go to whatever antenna or
load is connected. The "Output" position of the
Mark II meter circuit will indicate exciter output,
and may be usedconveniently as a tuning meter.
Simply adjust the exciter controls for maximum
output, usirg whatever tuning procedure is pre-
scribed for the particular exciter. Then switch
the exciter back to standby or receive position.
2. Turn the Mark II function switch to the "TUNE-
CW" position, and allow several seconds for
filament warm-up. Leave the meter switch in
"Output" position. Set the bandswitch to proper
band position and the P.A. Load control to 9
o'clock. Illumination of the meter indicates that
power is on, and the tungsten filaments in the
3-500Z tubes will be brightly lit. As long as the
exciter is in" Standby” mode, and the Relay Con-
trol circuit :s open, the 3-500Z tubes are biased
to cut-off. IP and IG, (plate current and grid
current, respectively), should read zero when
tested. EP, (plate voltage), should read approxi-
mately 1600 volts, depending on power line
voltage.
3. Turn the Mic. Gain down on the exciter (trans-
ceiver), and be sure the carrier has been bal-
anced out. Then switch the exciter to normal
Voice-Transmit position. With the Swan 350 or
500 transce ver this is done by pressing the push-
to-talk button. If the relay control circuitry is
properly connected and functioning, the Mark
II is now in Transmit mode, and the red indi-
cator light on its panel willbe on. The 3-500Z
tubes will now be drawing "idling Current," so
IP willread about .1 amps. and EP will be about
1500 volts. IG should still read zero.
4. Switch the Exciter to its "TUNE" or full CW
power position. Quickly adjust P.A. TUNE on
the Mark II for maximum output, as indicated
by the meter in Output Position. Then go back
to the Exciter and adjust its P.A. TUNE for
maximum output. (It may have changed slightly
when switched into the amplifier cathode circuit. )
Next advance the P.A. LOAD control on the
Mark II for increased output, and then alternate
between adjusting P.A. TUNE and P.A. LOAD
until the highest possible output indication is
reached. Set the Output Level Control as required
to keep the meter from going off scale. The out-
put reading is a relative indication, only, and
will vary considerably with different antenna
loads as wll as with frequency. CAUTION:
DO NOT KEEP THE EXCITER OR TRANS-
CEIVER IN TUNE POSITION FOR LONGER
THAN 30 SECONDS AT A TIME. This cau-
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