[Yaesu] Re: Pin Diodes FT-990 and FT-990 HISS

[Stuart Rumley]

I agree John...Its really sad since this radio has such great potential.  As
I've mentioned previously, if someone is willing to donate a radio (FT-990),
I would be willing to investigate and fix this problem (returning the radio
eventually of course).  My company specializes in RF/Microwave design and
product development.  Since this radio has plug-in boards, we could make a
new board and offer it as a retrofit kit if there is enough interest.
Personally, I would find it an interesting challenge to restore these radio
to the quality that many owners expected of them

Stuart,  ki6qp

www.valontechnology.com


----- Original Message -----
From: "John Bolduc" <hydro@fx2.com>
To: <yaesu@mailman.qth.net>
Sent: Monday, February 11, 2002 9:55 PM
Subject: Re: [Yaesu] Re: Pin Diodes FT-990 and FT-990 HISS


| Stuart
|     And for me an easier way was to simply disconnect the 10 meg IF from
the
| 455...... The way to do it on this is, since the radio  does not have the
CW
| filter in the 455 is to enable the front panel bandwidth button by
flipping
| the dip switch on the control board . Now you can unhook you antenna , And
| listen to the receiver noise & turn the front panel bandwidth button from
| 2.4 to 250hz to disconnect the front end . And guess what the noise does
not
| change hardly at all......... SO the receiver front end 10 meg & forward
is
| NOT the problem.
|
|  Stuart ,  one time as a experiment tap off the product detector BEFORE
the
| active LOW pass filter......with a hi fi amp to listen ........I could not
| believe what a racket of noise that 455 IF section make!!  I can't believe
| yaesu design this !! and the 1000MP is the same circuit. I have done the
| same test with my Kenwood TS-850 and guess what it's quiet as a mouse AND
| has NO active low pass filter to muddy up the receiver audio.
|
|  Shame on Yaesu !! Thats coming from a loyal Yaesu man ..
|
| 73's john
|
|
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