Good Afternoon All,
I'm curious about the experience of others in the matter of utilizing possible
"...substitutes" for the frequency band oscillator crystals --- be they
synthesizers, self-excited "analog" oscillators, whatever --- in the R-4 series
of receivers, to expand the frequency coverage of same...
To date, my research has come up with three different articles on the subject,
i.e.:
--- August 1972 HAM RADIO magazine ("Frequency Synthesizer for the Drake R-4";
--- May 1981 QST magazine ("General-Coverage Reception with the Drake R-4C",
and,
--- June 2004 April QST magazine ("Give that Drake Receiver a New Lease on
Life").
Of all these, the May '81 QST appears to be about the simplest to construct,
even though it uses a pair of the now relatively expensive ECG222 (come
NTE-222) dual-gate Mosfet transistors...but how in the world does one attain
(and maintain) solid, stable, & steady crystal-like oscillation in a relatively
simple Colpitts circuit, as high as 40.8-MHz...?!
I'm putting out feelers at this time, because in three short days from now, I
shall be the proud owner of a pair of Drake Twins here...a Christmas present
that I am presenting to myself, just a few days ahead of THE BIG DAY, Hi Hi.
Thanks in advance, & my vy
~73~ Eddy VE3CUI - VE3XZ
