Here is a nice article with embedded videos demonstrating the C-21:
http://www.hamradioqrp.com/2015/10/ten-tec-century-21-cw-only-rig-ahead-of.html
Incidentally, the C-21 was designed by Dick Frey, K4XU, when he worked for
Ten Tec in the 70's.
Reed / WW3A
On Sat, Dec 30, 2017 at 3:14 PM, Dukes HiFi <dukeshifi@comcast.net> wrote:
> I myself could have been a bit more tactful as well.
>
> However, direct conversion has so many adverse artifacts that it makes me
> cringe to think of using it. The C21 is quite a lot better, IMHO than is a
> true “direct conversion” design.
>
> The new SDR direct conversion process is a different matter with different
> issues, some good, some not good. But at least they don’t suffer from
> arbitrary sideband, hum and adjacent frequency overload (unless you send
> the A to D into overflow).
>
> 73
>
> Gary
>
>
>
> > On Dec 30, 2017, at 1:24 PM, Lee <lee@wa3fiy.com> wrote:
> >
> > Yes, both Century 21 and 22 hear both sidebands all the time.....just
> LIKE a simple direct conversion receiver. Granted, the conversion details
> of both radios differ from a simple direct conversion receiver.
> >
> > I may have started this discussion when I said "...It tunes just like a
> direct conversion receiver where you hear both sidebands as you tune thru
> the signal...." in response to the original question. Emphasis maybe
> should have been put on the words "TUNES JUST LIKE". Sorry, I should have
> been more clear I guess. :-)
> >
> > HNY everyone,
> >
> > 73,
> >
> > -Lee-
> > WA3FIY
> >
> >
> > ------ Original Message ------
> > From: "w0ep" <w0ep@w0ep.us>
> > To: tentec@contesting.com
> > Sent: 12/30/2017 1:56:17 PM
> > Subject: Re: [TenTec] C22
> >
> >>
> >> I must be misunderstanding..
> >>
> >> My C21 hears both sidebands all the time.
> >>
> >>
> >> On 12/29/2017 10:47 PM, Dukes HiFi wrote:
> >>>
> >>> Its advantage over direct conversion is freedom from hum and images
> (wrong sideband).
> >>>
> >>
> >> _______________________________________________
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> >> TenTec@contesting.com
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> >
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> > TenTec@contesting.com
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>
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