Mixer FET in Heath SW-717

[Richard Post]

Heathkids,

It's totally solid-state so it's not my normal boatanchor line of inquiry.
I suspect Q2, the mixer in this radio.  The oscillator is functioning, and
I can pass modulated IF beyond the mixer.  The voltage on the source is
definitely too high (3.2 volts instead of 0.4).  Just a good 100 ohm
resistor to ground connecting to it so it is drawing more current than it
is supposed to.  Drain is low and Gates are at and a bit below normal
voltage.  This is an RCA 417-240K  914 which, in the NTE reference
database, crosses to an NTE-222 dual gate N-channel MOSFET.

SInce one of the gates is only a tuned circuit and a cap away from an
antenna input, I assume it may have been damaged by a good static shot.  I
had also suspected the two ceramic filters that are at the output end of
this FET.  Any other possibilties here?  Has anyone else had trouble with
the mixer FET or the ceramic filters in their SW-717?

Rich

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