The above picture was my AM station that I had in Massachusetts. Pretty much everything is homebrew. Next to me is my latest AM transmitter and linear amplifier for 75 meters. The amplifier was built overkill since I was using it for AM service. I had forced air into the bottom of the tube sockets and a power supply transformer rated for 1 amp at 3000 volts. The rack holds another AM transmitter which was crystal controlled and plate modulated by a pair of KT-88's. The final amplifier was a 4-65A with a 5763 and 7984 in the driver stages.
I currently hold:
This is my current AM transmitter for 75 meters. It is a single tube 7984 being Heising plate modulated. Two watts from any 50 ohm RF source will deliver 15+ watts carrier.
At the ARRL Headquarters on 1/3/2011. Left to right is our ARRL tour guide George Carbonell N1RMF, ARRL CEO David Sumner K1ZZ, my wife Angelica and me. Below, Angelica is sitting at one of the W1AW main operating stations and I'm at the vintage AM station.
This was one of my AM transmitters using external RF drive and audio. This used a pair of 7984's for 30 watts output.
This is yet another AM transmitter creation using KT-88's for audio, a 4-65A in the final, 7984 driver and 5763 crystal oscillator.
This was a CW rig for 30 meters and was crystal controlled using a VXO circuit, and below is a better view of my linear amplifier.
The first picture below was taken with my friend and co-worker Dick Spicer, KC7DLW, at the Mystery Castle in Phoenix, AZ. We work for the City of Mesa's Communications Department. Shortly after I signed on with the city, Dick brought in his 4CX10,000 tube and we talked about building a "legal limit" AM transmitter. Assuming we could afford the electricity bill, that would make us pretty much the Channel Masters of the southwest.
The next picture with AM radio guru Tim Smith, WA1HLR, was taken at the Boxboro, MA hamfest in 2010. Tim and Steve Cloutier, WA1QIX, helped me troubleshoot my linear amplifier on the air. After a few minutes of old buzzard transmitting, the plate current would drift dramatically with an associated drop-off in power. Tim convinced me to build a new plate choke out of pvc pipe and Steve suggested changing the DC blocking capacitor. Problem solved.
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