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Old 9th Oct 2019, 2:01 pm   #12
Radio Wrangler
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Join Date: Mar 2012
Location: Fife, Scotland, UK.
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Default Re: ECF82 frequency changer

Note that in the circuit Andy's posted, the coupling is scaled down by thecoupling winding on the oscillator coil and that the coupling is applied to an undecoupled cathode resistor in the pentode.

In the first circuit everywhere stray coupling could have gone to was shunted to low impedance with either an off-tune tuned circuit or else a decoupler.

David
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