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TopBand: Follow-up on Topband Receiver Survey

To: <topband@contesting.com>
Subject: TopBand: Follow-up on Topband Receiver Survey
From: k6se@juno.com (Earl W Cunningham)
Date: Tue, 10 Feb 1998 01:58:15 EST
The ham that sent me this message wishes to remain anonymous.  It might
be of interest to topband owners of FT-1000MPs.  

--------- Begin forwarded message ----------

Earl,
Your question about key clicks is very relevant.  It is a serious problem

with many of the newer rigs.  I can describe my experience with the 
FT-1000MP.  My intent is not to criticize Yaesu.

Just before my one-year warranty ran out, I returned my FT-1000MP to 
Yaesu to see if they could get rid of the spikes at the leading edges of 
CW characters.  The radio has an obvious spike at the leading edge of any

CW character that follows a space long enough for the transmit ALC to 
decay to its quiesent value.  There is also an equivalent "fuzz" on the 
transmitted SSB signal that I suspect also comes from problems in the ALC

attack time constant.

The resulting operational problems are:

(1) Inflated readings on any device that reads peak output power.

(2) Premature tripping of protection circuitry in an amplifier like an
    Alpha 87A or 89.

(3) Key clicks on CW.

(4) Strange sounding spurious sidebands on SSB.  These sound a little 
     like the splatter that results from flat topping, but not really the

     same.

I sent my FT-1000MP to Yaesu around the first of December.  After not 
hearing from them for six weeks, I called to inquire.  They said that 
they could observe on the scope both problems as I described, but that 
they didn't think these problems were of any concern for normal 
operation. They also said that they had received very few complaints
about 
such problems and that mine was the most detailed complaint.  They 
intended to return the radio without doing anything -- I think, because 
they really didn't know how to fix it.  Clearly, these are design 
problems, not the result of component failure or misalignment.  I 
objected and asked them to try harder.  That was about two weeks ago. 
Since that time I have heard nothing and they haven't responded to my 
inquiries.

I still consider the FT-1000MP to be the best receiver I have used on 160

meter CW.  I just want Yaesu to address the transmitter problems, if they

can.  It remains to be seen whether they will succeed.  One point that is

very clear is that few owners have complained.  Perhaps this is the point

to make to topband operators.  If you don't like the design features of 
the radio, say something.

The TS-930S had perfect QSK in 1983.  The CW waveform was well shaped and

the timing was perfectly preserved at any keying speed. This was achieved

by using a simple shift register to delay both the "make" and "break" by 
about 6 ms to allow time for relays to close while perfectly preserving 
the CW timing. After a little study of the circuitry, one could optimize 
the delay to match any amplifier QSK system by changing the value of a 
single capacitor. Very few manufacturers since 1983 have been able to 
match the performance of this simple system.  This is baffling and 
frustrating to serious CW operators.

--------- End forwarded message ----------




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