Note that a spectrum analyzer should be used to ensure that the scheme used is
not rich in harmonics, spurious responses, and so forth.
-----Original Message-----
From: EP Swynar <[EMAIL PROTECTED]>
To: [EMAIL PROTECTED]
Sent: Wed, 19 Dec 2007 12:33 pm
Subject: [drakelist] R-4 Series Crystal Alternatives
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
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