Hello. Have gathered a bunch of parts with the intention of building a nice mw transmitter. I have a couple of PL519 tubes and was thinking of using them together with an art-13 mod transformer, but I have not settled for a design yet. I'm thinking maybe 2 of them in the rf amp, and 2 of them connected as triodes in the modulator. Any ideas, advice or schematics someone?
Given that it's a TV sweep tube my guess would be to parallel them in a grounded grid design for your RF amp section. There are many schematics floating around showing this configuration. No idea how much drive power they are going to require, but guessing it's going to be on the order of tens of watts to get a few hundred watts output. Another method would be to grid drive a PL519 with a 50ohm input load resistor to dump the current into since the tube will only be amplifying RF voltage. I think doing that would require less drive power ( <10 watts) to get up to 100-200w output. Using these tubes as a modulator may work okay in push pull configuration. I would think any schematics out there using sweep tubes as audio amplifiers would give you a cookie cutter plan to test them with.
Yeah, I'll probably go with grid drive. Recently built an all tube 6ag7/807 transmitter, but that one was fairly simple to get going due to all the information availible on the web. I tried cathode modulation on that one, sounded pretty good, although with only about 2watts of carrier.
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