[TenTec] C22

[Bwana Bob]

I bought a used C 22 some years ago and really like it.  Being direct 
conversion, it does not have single-signal reception, so you hear a 
signal on both sides of zero beat. If you hear QRM, just offset the RIT 
to the other side of zero beat.  However, it's not going to be good for 
contesting on a crowded band.  I use it mainly for traffic handling on 
80 meters

On the other hand, the PTO is very stable and the receiver is very quiet 
and with no filter ringing.  CW sounds really nice on it and the audio 
filter is quite good.  Unlike the ARGO, the C 22 has an RF gain control. 
One interesting thing:   I am plagued with neighbor noise on occasion. 
It is broadband modulated white noise with an S9+ buzz every 30 kHz. it 
is probably a plasma TV or switching power supply or battery charger.  
Amazingly, the audio filter in the C22 takes out most of this noise but 
the crystal filters and noise blankers in my Corsair and Paragon do not.

A word of caution:  Early models had problems with blowing finals and 
drivers until Ten Tec replaced them with 2SC1969s, which are still 
available fro RF Parts Co. Even with the better final, there is no high 
SWR protection and unless you have a 5 A fast circuit breaker or the 
matching Ten Tec power supply ( properly adjusted), a few dits into a 
mistuned or wrong antenna with blow the finals.

73,

Bob WB2VUF
On 12/30/2017 3:14 PM, Dukes HiFi 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 at 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 at w0ep.us>
>> To: tentec at 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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