Adjust T1107 for a reading on Ml101 that is 0.3 volt higher than the voltage stamped on the base of the thyratron
After 3 minutes, set the MAGNETRON POWER variac at 80 and press the START button. A bright flickering
violet glow should be observed in the two "windows" near the top of the electrode structure inside V1104, which
will cease when the START button is released. This indicates that the tube is firing through due to high reservoir
voltage. If the glow is steady rather than flickering, refer to (7) below before proceeding.
Caution: Press the STOP button immediately if a steady cherry-red glow is seen through the upper window
of the tube. Refer to (8) below.
Press the STOP button and decrease the reservoir voltage in increments of 0. 1 volt (observing the caution in
(1) above and starting and stopping the transmitter after each adjustment) until a steady bright violet glow is
observed through both windows.
The reservoir voltage is now correctly set. The required reservoir voltage may change with age and temperature
extremes, requiring a slightly different setting (usually lower than that stamped on the base of the tube) to
prevent irregular firing and plate overheating.
If the thyratron exhibits a steady violet glow when the START button is initially pressed, press the STOP button
and increase the reservoir voltage by another 0. 3-volt. Repeat the procedures in (4) through (6) above.
If a steady bright red glow is observed through the upper window and a steady bright violet glow is observed
through the lower window, the tube has a hot plate resulting from too low reservoir voltage. This condition can
result in serious damage to the tube. Adjust T1107 for an increase of 0. 6-volt and repeat the procedures in (4)
through (6) above.
c. Adjustment of Relays K1101, K110Z, and K1103.
Relays K1101 (high voltage power supply overload) and K1102 (reverse current - overload) are normally
adjusted only at general support level. However, should it be necessary to perform this adjustment in the field,
the following procedures will suffice until general support personnel are available. The transmitter must be off
during these adjustments.
(a) Remove relay K1101 from its socket and connect an ohmmeter between pins 7 and 8 of the socket.
(b) Adjust R1106 for an ohmmeter reading of 16 ohms. Disconnect the meter and replace the relay.
(c) Remove relay Kl10Z from its socket and connect an ohmmeter between pins 7 and 8 of the socket.
(d) Adjust R1105 for maximum resistance (approximately 100 ohms). Disconnect the meter and replace the
Two persons are needed in making the adjustment of relay K1103--one at the control-indicator group and the
other at the transmitter compartment.