[1000mp] Re: MP Clicks

Tue, 29 Jan 2002 18:05:58 +0200

I measured FT1000MpV keying wave shapes etc. with a spectrum analyzer. The
rise time from 0->100% is about 2.7ms and decay time is about 1.3ms.
Interestingly the raising edge of the first dot (or dash) after starting to
transmit has even a faster rise time than the consecutive dots - less than
1ms. If somebody wants to see them or put them for also others to see I can
E-mail the pictures from the spectrum analyzer (4 pcs).  My MpV serial
number is 0K130039.

Jaakko -oh8nj
----- Original Message -----
From: "Tom Rauch" <[email protected]>
To: <[email protected]>
Sent: Tuesday, January 29, 2002 6:19 AM
Subject: Re: [1000mp] Re: MP Clicks

> > look equally heinous." ========== I hope that the ARRL's new equipment
> > review editor is following this thread.  It's about time that the QST
> > reviews include CW keying bandwidth (clicks) specs as well as envelope
> > photos.  Maybe that will cause the manufacturers do something about
> > the problem.
>
> Excellent suggestion!
>
> That would have the end-effect of everyone complaining with their
> wallets.
>
> Certainly everything is inside the rigs already to make them click-
> free, for the most part they just aren't using the parts correctly. The
> cost would be virtually zero to build the things correctly in the first
> place, so it has to be because either they don't understand the
> problem or they don't care.
>
> A good first step would be to let Mike Tracy know we WANT an
> actual meaningful click and thump test...not some barely important
> first dot or multiple dot waveform.
>
> He responded to the request for a meaningful narrow frequency
> blocking and IM test.....and now we can see how good (bad) most
> rigs are at spacings within roofing filter bandwidth! That was a
> positive test.
>
> For steady repeating clicks a hundred-sweep peak storage with a
> narrow spectrum analyzer or a good selective level meter with peak-
> holding capability to measure actual bandwidth would work.
>
> A spectrum analyzer would miss things like the infamous IC-
> 775DSP "thump", so they'd need a sample and hold selective level
> meter or to use zero-sweep dispersion setting on an analyzer to
> determine levels of "bumps" when VCO's switch.
>
> Let's hope we can get them to include REAL click tests.
> 73, Tom W8JI
> [email protected]
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