>
I sold my Century 22 not long ago, so I don't have a manual for reference.
However, I recall the Century
22 was often called a "double direct conversion" rig. It has a PTO which tunes
the same range of
frequencies for all bands (can't remember the freq. range). The PTO signal is
then mixed with a crystal
oscillator, with various crystal frequencies, to bring it up (or down?) to the
operating frequency, as
required by a direct conversion receiver. The signal tunes on both sides of
zero beat, like other direct
conversion receivers.
So, by hooking the freq. counter up to output of the crystal conversion mixer,
going to the detector, the
counter would read the correct frequency, without any offsets, as required by
superhet receivers.
The Triton IV is a superhet, so you have to program in the IF offset to the
counter so it will read the
correct operating frequency. This is not needed in a direct conversion receiver
like the Century 22.
73, Winston K4CWQ
> From: "Harry N. Coates" <WA8HC@charter.net>
> Date: 2006/09/07 Thu AM 11:21:28 EDT
> To: <tentec@contesting.com>
> Subject: [TenTec] Century 22 Question
>
> Don,
>
> I've never owned a Century 22, but, I think TT used the same PTO mixer scheme
> in most of thier
radios..
>
> You can probably tap off the PTO.. But, the PTO output is probably 5.0-5.5
> Mhz not the final freq.. You
will have to adjust for the LO
> freq used at the mixer to display the true final
> output.. I did this for my Triton IV..
>
> GL,
>
> Harry
>
>
> Harry N. Coates
> Comstock Park, MI
> WA8HC@charter.net
> _______________________________________________
> TenTec mailing list
> TenTec@contesting.com
> http://lists.contesting.com/mailman/listinfo/tentec
>
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
|