Check-out and alignment form:   download pdf

PA protection for the CX7:
High S.W.R. Protection for Transceivers and Amplifiers, CQ, May, 1980, 63-65. download pdf

Modifications:
Screen-grid overload protection. download pdf
Power supply IC update.
LM380 or LM384 audio output.
High SWR protection. download pdf
RIT mod.
LED counter update.
IEC AC power connector and filter.
Line varistor protection; (3) V130LA10A.
Heat sink for power supply regulators.
QRP power control.
Automatic cooling fan.
Curtis keyer.
CW filter amplifiers.
31 MHz injection passband.
40 MHz passband.
IF gain adjustment; reduces AGC noise.
Sidetone level control minimum.
Spot level control minimum.
A-B spot level vs. A/T.O. spot level equalization.
PTO B shift on dual receive.
Counter input level modification to reduce frequency shift in dual receive.
Mike preamp for Heil mikes.
Patch cable routing modification to reduce hum.
Carrier oscillator adjustment.
Front end AGC adjustment.
Separate +15 regulator for AGC; eliminates AGC noise.
S-meter linearity.
PA keying.
Semi-QSK, using VOX circuits.
Driver protection.
Standby switch.
PA filament switch.
Connectors on PTOs; simplifies servicing.
+5 volt supply from filament winding; especially for LED counters.
Front panel sidetone level.
Positive PTT and KEY lines; for compatibility with other station gear.

Repairs:
Transistor replacements.
Filter capacitor replacements.
W104 factory error.
Meter light.
Surgistor: see check-out form.
8072 test adapter for TV7-D.
PTO overhaul.
Driver overhaul.
Board removal.
Test jigs for testing boards out of radio.

Operation
PA tuning; see check-out form.