[TenTec] Century 21

[Shawn Upton]

They sold the kits a few years ago, I think they still
do.  Couple hours of work, not too bad.  Here is a
good page on how to do it:

http://www.io.com/~n5fc/c21_pto.htm

I think I mused about putting the C21 onto 30m on this
list a while ago; while it may be possible, I was
worried about leaking from the LO: the PTO runs from
5-5.5MHz, the second harmonic would be on 30m.  Plus,
the C21 is not quite the usual DC reciever: it does a
premix scheme, downconverting the band to a 5MHz IF,
and then uses the PTO as the LO to do the last
conversion.  As such, it's not easy to convert it into
a superhet--but it's an interesting scheme, not sure
on the leg up on the more conventional method of
mixing the LO and then downconversion.

Anyhow, again, you'd need a 5MHz crystal to
downconvert, which is likely to be recieved also in
the "IF" portion.  Granted, it's going to be 100kHz
below the start of the band, but it would obliterate
WWV most likely.

IIRC, it does cover 10m, and it may do the 28-28.5 and
28.5 to 29 as two seperate bands.  It may be possible
to rewire the switch, to pull in the 20m filter(s) and
then swap the 28.5MHz cyrstal (should be something
like 23.5MHz) to a 5MHz crystal or thereabouts.

Oh yes--it did come with a speaker.

Shawn KB1CKT

--- jfelts <jfelts at rap.midco.net> wrote:

> Just won a C21 on that place yesterday. Set turns
> on, dial is frozen and 
> thats all the owner knows. I don't think those rigs
> had a speaker maybe they 
> do but I figure it just needs the PTO rebuilt.
> Ten-Tec use to sell PTO 
> Rebuild Kits for them. Does anyone happen to know if
> they still do or not? 
> Rough idea of cost??  I sent them a email but of
> course they are closed for 
> the weekend, I just want an idea of whats ahead of
> me.
> 
> Last question and I'll shut up, is it possible to
> put it on 30m too??
> 
> Jerry - NR5A - South Dakota 
> _______________________________________________
> TenTec mailing list
> TenTec at contesting.com
> http://lists.contesting.com/mailman/listinfo/tentec
> 


Shawn Upton, KB1CKT

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