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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: <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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