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Re: [TenTec] almost OT (involves Omni VI)

To: <geraldj@storm.weather.net>,"Discussion of Ten-Tec Equipment" <tentec@contesting.com>
Subject: Re: [TenTec] almost OT (involves Omni VI)
From: "Bob McGraw - K4TAX" <RMcGraw@Blomand.net>
Reply-to: Discussion of Ten-Tec Equipment <tentec@contesting.com>
Date: Fri, 14 Dec 2007 21:53:16 -0600
List-post: <mailto:tentec@contesting.com>
Also in the Omni VI Plus, turn off the NB {noise blanker.

Bob, K4TAX

----- Original Message ----- 
From: "Dr. Gerald N. Johnson" <geraldj@storm.weather.net>
To: <tentec@contesting.com>
Sent: Friday, December 14, 2007 11:25 AM
Subject: Re: [TenTec] almost OT (involves Omni VI)

> On Fri, 2007-12-14 at 07:28 -0600, atrampler@att.net wrote:
>> I've noticed that with my Omni VI (opt 3) on 40 meters I will clearly 
>> hear key clicks from some stations, with what sound like true keying 
>> sidebands when they are stronger than S9+10 or so, and keying with a bug 
>> or straight key.  These clicks or keying sidebands can be 5 kHz away and 
>> still S9+, and are not nulled by using the 500Hz 9MHz filter.
> This can be generated at their transmitter with simply a too rapid rise
> and or fall of the keying envelope, or can be generated in your receiver
> because of audio generated AGC and the inherent delay of the crystal
> filters. PAs that are over driven into class C can enhance clicks too.
> To see if its your receiver, or them, back off on the RF gain so your
> AGC has little effect. If the clicks disappear, its your receiver and
> its fast attack AGC, else its them and they need to do a bit of key
> circuit shaping to narrow their signal. One of the Orion complaints last
> year was that at lower than full power the rise time was shorter than
> set in its parameter. Hence a parameter value that would have been
> clean, was not so clean at lower power where the ALC was stopping the
> rise before the DSP shaping had all taken place.
>> There are some stations where I pick this up even if they are using a 
>> keyer...
>> So...question 1: can the use of a straight key or bug produce keying 
>> sidebands or clicks if good solid contact is not being made (as sounds to 
>> be the case in this situation); and
> A bouncing contact could make clicks worse.
>> Is the Omni VI especially sensitive to the received CW wave form (perhaps 
>> due to something in its AGC structure)?
> Its been more of a problem in early TT radios.
>> I have listened with AGC fast, slow and off...and these keying sidebands 
>> and/or clicks are still there.
>> So is it me...or just that many crappy signals on 40 meters?
>> Art, K0RO
> 73, Jerry, K0CQ
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