Hi Andy,

I don't know if you want to do any experimenting. If you do, one
thing to consideris to not use a 602 as the product detector in that
conversion. I have done it last month and it worked ok but I didn't
really see any difference in the performance of the receiver.
the original product detector, being made from diodes, was a low
impedance device. Consider replacing it with a DBM, since you already
have a low impedance source of 50 KHz LO. If you make the conversion
the authors did you end up moving the components to use the oscillator
in the 602 and end up having to attenuate the IF signal coming into
the 602 also. My only concern is the frequency response of the
packaged DBMs - they are speced at 500 KHz as the lower frequency
limit. Maybe using them at 50 KHz is pushing them too far.
I DID make the power supply and audio amp mods. The audio amp,
especially, is extremely crude. I can't believe Drake actually built
their audio amp that way (Class A with a transformer). I used a
simple little 380 IC mounted right next to the volume control and it
works fantastic.
I haven't done the earlier mixer mods yet, but so far the improvements
in heat reduction and consequent VFO stability are worthwhile.

Rick K2XT