The 1/3 Kilowatt KQ3M Repeater.
Built from a Motorola Micor Unified DVP (Securenet) Chassis and a GE Mastr Pro/II 1/3 kW VHF Station Amplifier.

 

Yes, that says 330 watts!!!

 

View of the Micor Chassis.  The 10 watt IPA was custom built from a Micor 110 watt mobile.
Notice the exciters output runs into a Micor Mobile antenna relay backwards.  This relay allows the selection of either of the two solid state power amplifiers.

 

View of the modified Station Chassis Modules.
The Station Control Module has a 3 position Transmit Switch.  Center switch position is normal where the controller keys the Station, Up is lock in transmit to permit careful tuning of the GE amplifier.  Down is disable where nothing can key the transmitter or amplifier.  A Red LED indicates the transmitter is "on the air" while the Green LED illuminates when the PTT is Disabled.

The Line Driver Module was stripped to a bare board.  A front panel Power Level Switch and series of control relays were added to allow the selection of either the GE tube PA (normally run at 250 watts output) or the "back-up" 110 watt Solid State Micor Station Power Amplifier.  Center switch position is normal where the controller can select (with a user function) which PA is used.  Up allows manual selection of the GE tube amplifier, while down selects the 110 watt solid state amplifier.  The relays are run from a 'wall wart' which defaults the relays "off" when the power fails allowing automatic selection of the transistor PA which is battery backed.

 

A view of the interconnecting wiring from the Motorola to the GE Cabinet.

 

Inside view of the modified 110 watt Micor Mobile PA circuit board.
This 110 watt Micor mobile PA has been severely modified to produce a 10 watt driver for the GE tube PA.  The 110 watt circuit board was (literally) hack-sawed in half and a custom output transformer wound so the impedance of the second transistor is matched to 50 ohms.  All filtering, metering, and Power Set Control circuits were retained to provide a clean and stable 10 watts of drive for the GE tube type power amplifier.

 

A picture of the 4 cavity Wacom duplexer, permanent Bird Wattmeter with selector switch, and "duplexer output" sampler.

 
 

In addition to the sampler on the duplexer output, one is placed on the duplexer input (amplifier output).

 

The information presented in this web site, on these web pages and in these modifications and conversions is © Copyrighted 1995 - current by Kevin Custer W3KKC.