[1000mp] Key Clicks

Thu, 2 Jan 2003 14:22:37 -0500

Speaking of measurements, I used an oscilloscope and Bird RF sampler to
inspect the CW keying waveforms produced by my unmodified FT-1000D and
FT-1000MP:

 Radio         Purchased      Rise      Fall

FT-1000D     01/24/01 (new)  3.5 ms    2.5 ms
FT-1000MP    04/01/99 (new)  2.0 ms	   1.0 ms

The waveform shapes are similar to each other and to those found on W8JI's
site. W8JI says that you can't go entirely by the keying waveform, but it
would appear that my MP's risetime is more than twice as fast as the ARRL
recommendation and the fall time is five times faster. It seems likely that
this radio produces clicks. The 1000D, on the other hand, isn't quite as far
off the ARRL recommendation.

Next step is some receiver tests. If they're bad, I'll do the mods. For
better or worse, I've never been afraid to dig into a high-dollar radio.
I've saved a lot of heartache, shipping and repair bills that way. I started
by working on cheap hamfest radios and worked my way up. I have to admit
that I've made a couple of errors that required further repairs, but have
learned to take my time, study the schematics and tech manuals thoroughly,
use the right test/repair equipment, double and triple check everything, and
go slow, slow, slow. It's very satisfying to make a mod or fix a problem in
a modern transceiver.

73, Dick

> -----Original Message-----
> From: [email protected]
> [mailto:[email protected]]On Behalf Of Garry Shapiro
> Sent: Thursday, January 02, 2003 4:28 AM
> To: [email protected]
> Subject: [1000mp] Key Clicks
>
>
> All:
>
> Uniform measurements by a group of individuals are only possible if all
> measurements conform to a standard procedure using identical
> tools. But this
> has not been the case in this thread in evaluating either the click
> performance of an unmodified radio, or the improvement due to
> modification.
>
> Those reporting are using different radios with different filters. Putting
> aside the differences in filter shape factors, we see
> measurements performed
> with single and cascaded filters of various bandwidths, mounted
> in different
> radios, evaluated by operators of widely different technical
> backgrounds. My
> suspicion is that the variations in the radios of a given model
> are probably
> less than the deviations in observation.
>
> As there appears to be no uniformity in the methods reported, the
> implication is that we each can compare our own measurements taken before
> and after any click modification, and thus obtain at least a qualitative
> evaluation of the efficacy of the mod. But it would be foolish to extend
> that reasoning to others' reports, and perhaps especially the "no clicks"
> reports.
>
> I just took a look at my own MP, using a TS930S with cascaded 400 Hz Inrad
> filters. Not having a calibrated attenuator, I had to use S meter readings
> vs. deviation from signal frequency. While this can  provide a useful
> benchmark for comparison with results after mod installation, it
> is useless
> to compare with anyone else's results, and, even for my own use, is no
> better than the accuracy of the S meter. My results show that my MP has
> observable clicks, period. They do not show whether my radio is worse than
> your radio.
>
> I plan to obtain a calibrated attenuator, which will at least provide an
> accurate measurement of relative response vs. frequency--for the filters I
> have. But, with filter bandwidth on the order of the bandwidth of the
> observed effect, this is still a low-resolution measurement.
>
> The results on W8JI's website are for the MP's he measured---more
> than one.
> They may not accurately portray every MP in use, but they are quite likely
> to be representative of most. Moreover, Tom's measurements, with
> professional equipment, are more likely to be accurate than the
> measurements
> most of us are performing.
>
> In my own case, I observe enough clicking---and have received
> enough reports
> from others--to convince me that action is required, and that any
> improvement will be welcomed by those with whom I try to coexist on the
> bands.
>
> Garry, NI6T
>
>
>
>