[TenTec] century 22

[Carl Moreschi]

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 at 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 at 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 at cox.net>
>> wrote:
>>>>
>>>> Buy it....lots of fun but don't sell your Omni6+!
>>>>
>>>> Richard K1MD
>>>>
>>>> -----Original Message-----
>>>> From: TenTec [mailto:tentec-bounces at contesting.com] On Behalf Of
>> Michael
>>>> Tortorella
>>>> Sent: Friday, December 29, 2017 11:42 AM
>>>> To: tentec at 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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