What to do with a CK722 in 2024?

[old_tv_nut]

Originally Posted by Airedale

Is this a viable design?



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I think a 1M ohm resistor from the junction of the diode and the 0.02 microfraad to ground may be needed so the rectified voltage can discharge and follow the modulation. Then you might try adding 10 or 20 pF in parallel with the 1M ohm to filter out any remaining RF at that point.

This page offers a couple of alternatives inlcuding one where no diode is used and the transistor rectifies the RF. Don't know if that will work with a CK722. Its response may be too slow to make a good RF rectifer, so the combo diode and transistor circuit is a better bet.