My First Transmitter 6AG7 driving an 807


I started talking about building my first rig in the last post and said that my Elmer, Carl Wilson (W4IUD) helped me build my first transmitter, which was a 6ag7 tube driving an 807 tube, and it probably did good to get out 25 watts. After I got my ticket down in Atlanta Carl said, “Now that you got your license you need a rig to get on the air. Come on over to the house and we will see what we can do.” I went over to Carl’s house there in Marietta, Georgia the first free evening that I had. He had the schematic that I posted last time, but he really didn’t need a schematic because he had it all in his head. We rummaged through his junk box until we had enough parts to proceed to solder them together. We first made the chassis by taking an aluminum box and a Greenlee chassis punch and made the holes for the tube and coil sockets; we installed the solder lugs under the chassis and proceeded to assemble the transmitter. It was lot of fun and learning, but I’ll have to admit that Carl did most of the work. We put a metal cage over the top of the rig to keep the 807 from radiating until it got to the antenna. He also showed me a trick where you can use an incandescent light bulb for a dummy load picture of 807 tubeand tune the rig up to get the brightest light out of the bulb as you dipped the plate. You would make adjustments on the grid and then dip the plate current till you got the maximum out that you were going to get. A 40 watt bulb was just right to do the tirck. Then theoretically it would be loaded for a 50 ohm antenna.
My first receiver to use with the transmitter was a Hallicrafters that was so broad that it would receive a whole band at one time, but it had a small bandspread knob on it, which would give a little separation but one could still hear several stations at one time. Later when I thought that I was wealthy I replaced the Hallicrafters with a Heathkit HR10 which I thought was a great improvement. I ordered a kit and watched the mail waiting for it to come. When It did arrive, I really had fun sorting and identifying all the parts, and then I soldered it together but when I had it all done I turned it on and heard nothing. I was very green at troubleshooting at the time. So I had a friend from church, actually my father’s age who worked in electronc repair. He was not a ham himself, although he worked in electronics repair. He was one of those people who are naturally good at doing things. He also liked to fish and building fishing boats. Well, he took the receiver, and right away he said, “you’ve got the B plus voltage shorted out.” In a jiffy, we fixed that and the receiver worked liked a charm that is if you didn’t go above 20 meters where the sensitivity was quite lacking.
I made my first qso on 40 meters with a station in Pensacola, Florida, which was quite thrilling. In fact, my hand was shacking on the key when I went back to him. But everything went well and I had made my first contact. However, my heart continued to race and my nerves jumping for a good long time every time I made a contact.

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About tladotse

I am a retired Electronics Engineer who specialized in circuit design, antenna design, reliability and maintainability. I am an amateur radio operator and also have hobbies of fishing and photography. Getting kinda old but still get around pretty well.
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One Response to My First Transmitter 6AG7 driving an 807

  1. Harvey KM4JA says:

    Good story Kenn! My first transmitter was a Knight T-60 which I couldn’t get to work any station until my Elmer proved it would work. Receiver was probably like yours: a Regency shortwave receiver, 550 kc to 30 Mc. in 4 bands. But 45 years ago the 14th of this month, I worked my first station as a Novice. He was there in Nashville where I grew up and was a student at Vanderbilt. Worked 5 stations that first day. Exciting stuff! 73, KM4JA

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