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    PL504 instead of 6dq6 in transmitter

    Hi, in this design, can I use the PL504 instead of the 6dq6, since the last grid of the PL504 is internally connected to the cathode?

    What changes would be needed, and what short of performance (output power) would you expect at the same anode voltage?
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    Re: PL504 instead of 6dq6 in transmitter

    It should work, but as mentioned before, it is always better to amplify a stable oscillator signal than generate all the power in one stage.

    Note that the PL504 does not have a standard base size, it is bigger than most tubes. Also note that the heater alone needs 10W of power! It is designed for 0.3A series connection but needs 27V across it.

    I think if you are trying to produce more than a few Watts RF power it would be wise to use a large quartz crystal. I suspect if you use a very small one it may be overloaded and have a short life. Be careful about he voltage across the key contacts, it may be as much as 40V with the key open.

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    Re: PL504 instead of 6dq6 in transmitter

    since the last grid of the PL504 is internally connected to the cathode
    That's the case for all pentodes, also 6dq6. Reading datasheets strongly suggested.



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