It is important that the dust cover be tightly in indication of a short in trinimcr condt*nser Cl or in
place after each adjustment, because the freciucwcy thc. first two sctctions of tho main tuning condenscbr.
calibration is affected by the dust cover. If these symptoms occur, search out and clear the
The vacuum tube voltmeter should be used to short with ;L weak air jet or other means. I)o not
check the output of the instrument after the cali- bend the condenser plates as this affects frequency
calibration.
bration has been adjusted. Set the dial to ?100?
and the AMPL control to about ?80?. Connect the
VTVM and measure the output of each range. If Dial Coupler
the range switch has been properly adjusted, the
An insulated coupler connects the main tuning
difference between the output of the three ranges
with the dial set at ?100? should be within 1 db, dial to the shaft of the main tuning condenser. If
preferably less. the coupler becomes loosened, rotate the condenser
completely clockwise. To do this it will be nccessary
Trimmer Condensers to loosen the collar of the stop on the rear of the
panel bearing. When the condenser is completely
Two trimmer condensers are provided for the
main tuning condenser. These trimmers are adjust- closed, set the main tuning dial so that the clot to
the left of ?20? on the main tuning dial is exactly
ed at the factory and do not require further adjust- under the hairline. Tighten the wupler with tht-
ment for the life of the equipment. If the trimmers tuning dial and tuning condcvisw in these rthtive
inadvertently become misadjusted directions for positions. Then tighten the collar of the stop so that
resetting should be requested of -hp-.
the tuning condenser rotor cannot strike the frame
or stator.
Intermittent Output After the coupler has been tightened and the
Jumpy or intermittent output accompanied by dust cover replaced, it is desirable to check the cali-
flashing of the 3-watt oscillator lamp is a reliable bration of the instrument.
5 |
ACEC
