Hello Ten Tekies,
The bandwidth of a CW signal is dependant on the keying Speed as well as
the rise and fall time of each cw element. If keying is too soft it is
difficult to copy a weak signal with QRN. (Not that QRN would ever be a
problem on "top band"!)
Bill - K6WLM
Omni VI+
Ron Feutz wrote:
>
> How about this, guys?
>
> I have always been under the impression that my signal was clean and the
> Yaesu guys were screwing up the bands.
>
> Ron - WA9IRV Omni 6+
>
> >To: topband@contesting.com
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> >From: k6se@juno.com
> >Subject: Topband: More About Clix
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To: <tentec@contesting.com>
> >Date: Mon, 28 Jan 2002 14:41:16 -0800
> >
> >Virtually all of today's modern rigs have a key click problem. The stock
> >FT-1000MP and Mk V CW signal rise time is 2.4 ms and the fall time is 1.0
> >ms. This is on every dit and dah. The ARRL criteria for "clean" keying
> >is a rise and fall time of 5.0 ms. After the INRAD keying improvment
> >mod, the rise time is 4 ms and the fall time is 2.2 ms. It certainly
> >improves the keying, but not enough, which is why I'm going to do the
> >W8JI key click mod on my MP.
> >
> >A friend has an IC-756 PRO which has clicks extending out at least +/- 1
> >kHz. Another has a late-model IC-775DSP which has clicks as bad or worse
> >than the FT-1000MP. Additionally, you can hear a "thump" on his first
> >dit or dah when he is operating split. Earlier model 775s have the
> >additional problem of generating a signal from the receive VFO when
> >operating split (becoming worse as the split frequency is smaller),
> >clearly an FCC violation. Icom knows about this problem because they
> >will upgrade the early version if the owner complains, but they won't
> >publicly confirm this problem.
> >
> >Many topbanders prefer the Omni VI+ because of its superior QSK and
> >excellent receiver. But even it has bad clicks. INRAD has thus far
> >unsuccessfully tried to develop a mod to correct this. George, W2UVG
> >(owner of INRAD) told me, "I have spent many hours working on the Omni
> >VI+ keying and ALC loop as it has a similar problem. The keying waveform
> >out of the first mixer is text book perfect, 5 mS up and down. Then it
> >goes through the ALC loop and the output has 1 mS rise time and 5 mS fall
> >time. This loop has a very slow decay time, and it doesn't change the
> >input shape. If I disable the ALC loop the radio puts out 100 watts and
> >the keying is perfect. But there is no power control, etc."
> >
> >Jim, N7JW has overcome the Omni VI+ click problem by using an FT-1000MP
> >with the W8JI key click mod to transmit and an Omni VI+ to receive. It
> >would be nice if all hams (especially topband contesters) were as
> >concerned about having a clean CW signal as N7JW is.
> >
> >I'm not sure how the modern Kenwood radios are as far as clicks go.
> >
> >73, de Earl, K6SE
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