[TenTec] Century 22 Question

[jones_winston at bellsouth.net]

> 
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 at charter.net>
> Date: 2006/09/07 Thu AM 11:21:28 EDT
> To: <tentec at 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 at charter.net
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