[1000mp] Yaesu FT1000 Key Clicks

[George, W5YR]

I plan to repeat the keying spectrum tests using a variety of rise/fall
times and receiving bandwidths and filter types in order to get some idea of
the role the receiver plays in the "other" op's perception of the click
situation. These findings will probably appear on Adam's website.

While I regret that you find the data "meaningless" I might add that your
detective powers are working - the rise and fall times were four msec,
chosen to be a typical almost-worst-case setting. That parameter should have
been stated.

The data were taken and presented as comparisons between two rigs, not as
absolutes for either. The important thing for such a comparison is that both
rigs were setup identically. The plots confirm that a small improvement has
been made with the 746PRO. Much more is needed - no disagreement there.

While the rise and fall times have an effect upon the keyed spectral width
and shape, I have found from examining the keying of various rigs that the
shape of the keyed envelope plays an important role as well.

Specifically, if the transition from OFF to leading edge is "rounded" and
smooth without the usual sharp break; and the transition from leading edge
to ON is the same; and similarly for the trailing edge, the keyed spectrum
is narrower and fewer clicks are apparent to the listener.

Considering the firmware controlled nature of the keying process in the
PROs, it may or may not be feasible or even possible to alter the keyed
waveforms to any useful extent.

The PROs do a pretty good job of managing these transitions compared to
other rigs.

73, George W5YR
w5yr@att.net


----- Original Message ----- 
From: "Earl W Cunningham" <k6se@juno.com>
To: <1000mp@mailman.qth.net>; <w5yr@att.net>
Sent: Monday, January 12, 2004 10:36 PM
Subject: Re: [1000mp] Yaesu FT1000 Key Clicks


> George, W5YR wrote:
>
> "FYI, the 746PRO has a slightly narrower keying spectrum than does the
> PRO2. See Adam's website for my spectral plots."
> ==========
> I read the writeup that went with the plots, but I couldn't see where you
> specified the rise time menu setting of either transceiver, so the plots
> were really meaningless to me.
>
> If the rise times were equal, the 746 does appear to occupy less
> bandwidth than the 756.  They are both rather broad (obviously would
> cause clicks) -- probably with the risetime set to "4 msec".
>
> It would be interesting if you ran the same test, but with the rise time
> set to "8 msec" (which is really 5 msec according to W8WWV's o'scope
> plots of the CW envelope) for both radios.
>
> 73, de Earl, K6SE