First Name Stan
  QTH Madison, WI
  Prior Call(s) ⇰ 
  Other interests ⇰  
  Email N9HMA
  My External Web Site QRZ


Greetings from N9HMA - Stan in Madison, Wis. I was licensed in 1973 at age 16. My callsign then was WN9NHG. In recent years, my station primarily consists of vintage, "boat anchor" gear. It's just more interesting to me to find an old junker and make it work again. It's a nice sanity break from my day job in "postmodern" technology.

  The Homebrew 833A rig...
The 833A rig arrived as a few van loads of parts gutted from a Gates BC-1F that I saved just before it went to a large dumpster. I took only the innards because I have no room or muscle for the rest. I have built it up in a 1960's Gates equipment cabinet that was already well used and full of holes from previous use. It's thickness is a bit light for all this big iron, but it works alright. An E.F. Johnson Viking II is RF drive to a single 833A P.A. The P.A. is modulated by a pair of 833A's, the 833A modulator is transformer driven by a pair of 845's. I call this version 0.90. Needs a lot of work, but's it's on the air and sounds ok.

A box fan is the "blower" for the 833A power tubes. A pair of 845's can be seen on the side mounted audio deck. There is a lot of iron in this thing. Most components are temporarily mounted. Some are not mounted at all... The MOD iron sweeps flat from 20 cycles to over 25 kc. I use an Optimod 9100B as a 5 kc audio filter on the input.

10/10/2015 UPDATE: The 1200V and 2500V power supplies, which were previously bread boarded on the floor behind the rig, are now in the wooden cabinet at lower left. They include a variac for each. Above the power supply cabinet is the Viking II R.F. Exciter, Optimod in 5kc mode, TFT Modulation Monitor, Shure Mixer. The transmitter cabinet on right is largely unchanged from previous description. The plate switch on the Viking II operates a T/R relay and the plate relay. The original Square D contactor makes a reassuringly loud "CLACK" at start of transmission. I am currently operating at 200 watts carrier. I would be glad to talk to you sometime on this beast.

Complete info is available here at QRZ (page opens in new browser window)

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  Last update March 19, 2017