Hi Earl,
For anyone interested, Kevin W9CF has an analysis (and
demonstration I believe) of clicks on his Web page at
http://fermi.la.asu.edu/w9cf/articles/click/index.html
> I'd like to improve the CW waveform on my FT-1000MP, but I don't have
> the facilities to test for the correct resistor values for the W8JI
Most people report being successful with a 270k resistor as an
average value. If you aren't going to play with values, then you can
mount the additional components right across the existing
components. If you have a scope, you need at least 4 or 5 mS or
rise and fall on the envelope to be reasonably click-free. The key
factor to watch with a scope are sharp transitions in the waveform
slope, the slightest quick change in slope produces a click,
regardless of CW speed.
Mouser, Digikey, and other such places sell SM components.
> key click mod, and the INRAD click mod apparently only improves the
> trailing edge of the waveform.
The Inrad mod improves the clicks, but could be much better. For
some they allow a much faster rise and fall time than needed. If
strong, the signal will still be about 500-800Hz or so + and minus.
But at least it is noticeably better than stock, and we can live with
it if people stay 1kHz or more apart!
RC filtering is NOT the way to go with a quick rise and fall,
because the slope of attenuation is too low. It is possible, with
filtering, to generate a virtually click-free waveform with only a few
hundred Hz total bandwidth, and virtually no clicks outside that.
All the parts are already inside the radios to do that, the engineers
just didn't make good design choices.
> It is my understanding that the MP exhibits clicks only on leading
> edge the first dit (or dah) sent.
No, that isn't correct. 775DSP's have the annoying especially loud
closure "thump" as the VCO switches (followed by regular
keyclicks).
In the FT1000 series, the leading and falling edge of EVERY dot
and dash each produces a click. Every FT1000-series radio
manufactured, MP's, D's, and MP MK V's, clicks excessively. The
bandwidth of the clicks is about 2.5kHz no matter how fast or slow
you send, because they filter the CW through the SSB filter with
virtually no shaping.
The new IC756PRO MKII appears pretty clean, as do the few old
IC781's I've heard.
> I wonder if anyone has tried playing with menu item 7-4 (break-in time
> delay) to see if this has any effect on clicks in the MP. The factory
> default is 5 ms for menu 7-4. Although I never use QSK, I have mine
> set to 30 ms, and I've never had any complaints about clicks.
The menu will not correct the problem, because it is a lack of
filtering of the CW that produces the clicks. I'm sure the reason we
don't have more compliants is because, through training, we are all
reluctant to give critical reports. It was almost two years before
someone complained to me, and I was amazed once I check the
rig how bad it was.
We are also becoming conditioned to accepting clicks. We expect
them and accept them, even though they are certainly not
necessary. With limited space on CW, we can't afford 2-3kHz wide
channels.
73, Tom W8JI
W8JI@contesting.com
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