I designed an AM tube transmitter based on a crystal oscillator. Can you please tell me if this would work, or what I could improve?

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  • \$\begingroup\$ Make a tap at the output coil for the antenna and use a DC blocking capacitor, or better or a second winding with 20% of the turns and one end at GND. \$\endgroup\$
    – Jens
    Commented Aug 22, 2022 at 1:40
  • \$\begingroup\$ Thank you so much! I really appreciate your answer! I'm 15 and I'm trying to learn electronics, and your answer really helped me! \$\endgroup\$ Commented Aug 22, 2022 at 1:54
  • \$\begingroup\$ You need a DC setpoint of your output stage, the typical 1 Mohm from gate to a variable negative voltage. Start with -8 V and rise carefully because the output stage can overload easily. Red anodes -> OFF. I never used this kind of AM modulation. Your EL32 needs a cathode resistor or you cut away the upper half of the audio signal. \$\endgroup\$
    – Jens
    Commented Aug 22, 2022 at 2:07
  • \$\begingroup\$ Tube 6J5 is a triode, not a mixer type with two control grids like 6L7. \$\endgroup\$
    – Jens
    Commented Aug 22, 2022 at 2:24
  • 4
    \$\begingroup\$ It's not clear how things are getting modulated, and you've got too many resistor-coupled circuits in there. I strongly suggest that you get yourself some old ARRL handbooks from the 1950's or 1960's (to match the era of your tubes) and that you just copy the circuits therein, only making tube substitutions for like = like. Once you get a feel for how different tubes are than transistors, then you can branch out. Manuals should be available from eBay, Abe Books, or other usual old-book suspects. \$\endgroup\$
    – TimWescott
    Commented Aug 22, 2022 at 2:35


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