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Re: [TenTec] Omni VI cw signals

To: dtx@verizon.net
Subject: Re: [TenTec] Omni VI cw signals
From: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Reply-to: geraldj@weather.net, Discussion of Ten-Tec Equipment <tentec@contesting.com>
Date: Mon, 17 May 2010 10:23:30 -0500
List-post: <tentec@contesting.com">mailto:tentec@contesting.com>
Dirty power supply connections can happen to every user. Perhaps a 
regular cleaning interval is indicated, something like every year or 
two. Accompanied by a drop of DeoxIT on the contact surfaces to clean 
and delay the need for future cleaning.

Chirp from the voltage change at key closure might hint at a need for 
better voltage regulation of some oscillator, perhaps with a voltage 
regulator chip needing less head room than the LM34x or 78x families. 
Though that much voltage drop probably also leads to a serious loss in 
output power.

73, Jerry, K0CQ

On 5/14/2010 1:43 PM, dtx@verizon.net wrote:
> I have occasionally had a chirp report from my 0-IV, invariably caused
> by a dirty power supply connector and cured by a proper cleaning.  The
> scope pattern of its keying has been decent from the start - did take
> the time a few years ago to measure the rise and fall times - forget the
> numbers but since were in the range of above too sharp and below too
> soft at 35 wpm didn't bother to record.   K3TX.
>
> On May 14, 2010, *Dr. Gerald N. Johnson* <geraldj@weather.net> wrote:
>
>     There are also complaints of a chirp from the Omni VI. Typically heard
>     only by other Omni VI users. It is a fact that the BFO crystal is
>     shifted at key closure from receive to transmit. So it is heard at the
>     other end of the connection and passes through the SSB filter. I
>     suspect
>     the "click" and chirp are increased by the phase response at the
>     edge of
>     the filter pass band and increased more by the edge of the filter pass
>     band in the receiver that's detecting the signal. I know I've listened
>     to a supposed clicky and chirpy transmitter (Omni VI at W1AW on 20
>     meters) and found no hints of either click or chirp using a tentec or
>     other receiver even when I tuned to a very low pitch which makes chirps
>     more pronounced.
>
>     This topic has not been on this forum for a year or two, maybe three.
>     But there should be extensive discussions in the archives.
>
>     Fact is, you need a rapid rise which leads to a hard signal when you
>     run
>     CW above 15 wpm, faster if you run 40 or 50 wpm. Else the bits of
>     characters run together and get hard to copy. That also happens with
>     narrow CW filters from other vendors, it was noticable with a 400 Hz
>     filter in a Kenwood at speeds of only 25 to 30 wpm.
>
>     There are thousands and thousands of happy Omni VI CW operators happily
>     working rag chews, traffic, and DX without click or chirp complaints. I
>     don't have one simply because I prefer USB for CW, especially on VHF
>     with a transverter where USB is the standard voice mode and mixed mode
>     contacts are common.
>
>     73, Jerry, K0CQ
>
>     On 5/14/2010 8:29 AM, Roger Rippy wrote:
>      > "As you may know, most TT rigs up to the Orion series, have
>     fairly hard keying, and we have occasionally got comments about
>     "sounds a bit clicky".
>      >
>      > What is the consensus of the Omni VI operators? Do you routinely
>     receive these comments from others? I have not received a comment
>     about hard keying or clicking from my Triton IV, but then it is
>     quite a bit older than the Omni VI.
>      >
>      > Just curious since I am considering buying an Omni. Thanks, Rip
>      > Roger Rippy W7RIP Bozeman, Montana
>      >
>      >
>      >
>      >
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