Gary,
I think that you are saying that the C21 mixes all the RF input signals
across a switch selected 500 kHz band with a fixed crystal oscillator
signal. This creates a band inside the radio that is always at 5-5.5 mHz.
Then then the 5-5.5 mHz PTO tunes across that spectrum mixing (product
detector type) with signals and the difference frequency is AF.
Am I following that correctly?
If so, can we call it a double conversion DC receiver?
And, why do you favor that scheme over "normal" product detection such as
in the C22?
TU,
Garry WA1GWH
On Fri, Dec 29, 2017 at 5:07 PM, Dukes HiFi <dukeshifi@comcast.net> wrote:
> Whoda thunk???
>
> The C21 was a superheterodyne with a 5.0 to 5.5 MHz wide IF stage, fed by
> the RF input and the crystal oscillator for each band, and a product
> detector on the AF board that uses the VFO as the “BFO” to carry out
> product detection. It is NOT direct conversion.
>
> I had always assumed that the C22 was a repackaged C21 with digital
> display. WRONG!
>
> It is indeed a direct conversion radio. It premixes the PTO with the
> crystal oscillator for each band and shoots the result (which is right on
> the revive and transmit frequency) right into a mixer which direct detects
> signals, then on to the AF stage! What a downgrade compared with the C21!
>
> WHAT A DOWNGRADE TT made to produce the C22!
>
>
> If you have a choice, get a C21!
>
> Gary
>
> W0DVN
>
> > On Dec 29, 2017, at 3:04 PM, Winston <jones_winston@bellsouth.net>
> wrote:
> >
> > Good fun cw rig.
> > Winston K4CWQ
> >
> > Sent from my iPhone
> >
> >> On Dec 29, 2017, at 2:56 PM, Dr Richard San Antonio <K1MD@cox.net>
> wrote:
> >>
> >> Buy it....lots of fun but don't sell your Omni6+!
> >>
> >> Richard K1MD
> >>
> >> -----Original Message-----
> >> From: TenTec [mailto:tentec-bounces@contesting.com] On Behalf Of
> Michael
> >> Tortorella
> >> Sent: Friday, December 29, 2017 11:42 AM
> >> To: tentec@contesting.com
> >> Subject: [TenTec] century 22
> >>
> >> Hi all, I am contemplating purchase of a Century 22 and would like to
> hear
> >> what people on the list think of that rig.
> >>
> >> Thanks and 73
> >>
> >> Mike W2IY
> >>
> >> _______________________________________________
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> >>
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