Replace #387 lamps in filament, reset, and plate switches.

Mechanically zero the panel meters.

Clean Driver/PA blower blades by running screwdriver along blades to loosen dirt that builds up in them.

Clean overload relay contacts.

Replace capacitors on the three power gating cards and power control card.

Check to see if card cage relays and tighten contacts accordingly.

Fan over power supply should pull air in.  Reverse fan wiring and fan blade if necessary.

Check muffin fan on back of card cage at rear of transmitter. 

Move PA bias control and install extender shaft to front of transmitter so the control can be adjusted while the transmitter is running.

Lightly oil door interlocks and check low voltage interlock switches on them.

Add extra IPA door latches in center of door to make it the same as newest transmitters. 

Change rear door bottom screws to tapered type if traditional hex-head bolts are in place.  Continental part number 348-1004-010 for the screw and 786-0910-001 for the Delrin washer that goes with it.  This makes the back doors easier to put on. 

If the transmitter has 4CX250B driver tubes, install a shorted quarter-wave stub trap at the output of the exciter or input to the IPA.  This will prevent high voltages from a tube arc-over from damaging the exciter output stage.

Replace original nylon screws on PA fiberglass air chimney with thumb-screw type.  Continental part number 330-7031-020.  About $1.00 each.

Put the exciter into a dummy load and check for spurious radiation using a spectrum analyzer.  Replace capacitors on exciter RF output amplifier if spurs are found.

Check and adjust the Driver/PA air pressure switch so that it closes at 2” of Driver door opening.

Turn off the exciter and set the modulator bias controls so each tube has 120 m.a. of current for each tube.  Turn exciter back on.  It will be 170 to 190 m.a. when the transmitter is tuned and running properly.