But that's not what it does. It mixes the 5 to 5.5 vfo with the band
crystal to produce a frequency at the operating frequency and mixes that
with the received signal for detection just like any other direct
conversion receiver.
Carl Moreschi N4PY
58 Hogwood Rd
Louisburg, NC 27549
www.n4py.com
On 12/29/2017 5:47 PM, Garry Nichols wrote:
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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