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change in value of some other component connected across the
coil.
The value of any other parts connected across the coils is to
be considered insignificant when compared to the DC resistance
of the coil.
o
COUPLING EXCITER TO
FOLLOUING ST-GE
It is preferred that the final amplifier of the exciter be con-
nected to an external dummy lond of 51 ohms through a 51 ohm
cable while tuning,
Tuning the final amplifier in this manner
is a good check on its proper operation.
When changing the RF output connection of the exciter from a
dummy load to a following amplifier stage an attempt should
be made to get a proper match to 51 ohms at the input to the
follower amplifier stage.
If the output ccupling control, ' C169) and plate tune ( C167)
on the exciter unit, have to be considerably readjusted when
coupled into the succeeding amplifier stage, a major mis - match
of impedance is to be suspected at the input of the following
amplifier stage..
This will result in considerable loss of
drive to the following stage and cause high standing waves to
appear on the inter- connecting coax between the exciter and the
following stage.
Most of the amplifier stages that will be used following the
M6095 exciter unit will not generally require the full 10 watts
of driving power.
50 watt amplifier stage will require abou',,
2 watts of drive and a 250 watt amplifier about
4
watts of
drive,
In no case,
should C167 ( plate tune)
or C169 ( output coupling,
be de-tuned to reduce output power.
This is equivalent
to op-
erating
V115 in an off- resonant condition and would damage the
tube eventually.
Output power can be reduced to almost zero by tuning R167 ( ou.
put control;
tp a counterclockwise position.
This reduces screen
voltage to V115 and,
consequently,
the plate current which in-
creases efficiency to V115,
In some cases,
BI voltage of 320 volts will be tapped off of
TB101-6 to supply screen voltage to a following amplifier stage
-8-
M6095 Exciter
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