W7WRX - Clark
(previously KE7TRP)

Chandler, AZ

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The latest addition to the KE7TRP hamshack is a new-in-the-box Johnson 500 transmitter  that runs a 4-400A in the final, modulated by a pair of 811A's.  Paired with the HRO-60 receiver, it forms the archetypal, 1950's-era "serious" amateur station.

Click HERE or on picture for full-sized image.

This 100% homebrew transmitter provides a strong voice for KE7TRP on the lower bands.

Driven by a frequency-synthesized SSB/CW transceiver, it runs a pair of 4-400A's modulated by a pair of 304TL's for full, legal output on the 40-, 80- and 160-meter bands.  

The RF deck uses vacuum relays for bandswitching. 

The modulator uses the "iron" (mod. xfrmr, mod. reactor, capacitors)  salvaged from a Collins 20V3 AM broadcast transmitter.

Audio chain is an Ultra gain pro, 166XL DX, 32 band EQ and DAP310 audio processor. 

Both final amplifier and modulator have individual power supplies: 3500 vdc @ 1 amp for the 4-400A's and 3000 vdc @ 1 amp for the modulator 304TL's, and both are self-contained in individual racks. 

This project was assisted greatly by  Robert Smith, W0VMC.

Click here for more pictures of this rig.

Clark has documented various aspects of his station with videos posted on YouTube.  Here are links to the  YouTube  index pages for those videos:

Click here for Page 1 (most recent postings)

Click here for Page 2 (older postings)



Station 1:

Globe King 500C restored and upgraded (details here);  

Hallicrafters SX110 and SX-100 receivers;

Matching R48 speaker;  

802 mixing console and dbx 166XL audio processor;

MXL, large-diaphram condenser microphone and 'pop' screen.

(Click here for larger photo ~150K)

Perspective view of the audio processor, mixer, microphone and two Hallicrafters receivers.

(Click here for larger photo ~150K)

Click here for restoration details and photographs of the WRL Globe King 500C transmitter


Station 2: (160 or 40 meters AM)

Hallicrafters SX100 or SX110 (former pictured)

Yaesu Yo100 Scope;

Freq counter;

One of three transmitters: Johnson Valiant, Johnson Ranger or Globe Champion 300 (the latter pictured here);

D104 or EV638 mic.

(Click here for larger photo ~120K)

An itinerant denizen of the KE7TRP shack, this T-368 transmitter, here paired with a Hammarlund SP-600 receiver and a cat, was initially obtained from the estate of W7DI (sk) and then restored and modified to clean up some audio problems.  In 2012, it found a new home in sunny California.  This T-368 runs a single 4-400 final and was modified to use a pair of 4-250's in the modulator for a minimum output power of 375 watts.

(Click here for larger photo ~150K)

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