I looked in my 901DM service manual and don't see any problem in the
troubleshooting guide specifically related to the noise you refer to. The
closest would be 'no reception' or 'partial reception'.
The first thing I would try is getting some Caig DeOxit and cleaning the
contacts of all the controls (*especially* the band switch)
Failing that, a couple more pieces of info would be helpful to help you get
started in the right area:
1. Did this problem just start or did you just buy the rig and this is how
you got it?
2. Does this occur on all bands & modes? Or just some?
3. Does your S-meter work 'normally' otherwise
4. Does your marker still work?
5. Does Reject/APF/Clarifier 'work' (just still in presence of the S9
Finally, the nice thing about the 901 is it employs plug-in cards. The best
way to solve this is if you could find another 'good' 901 you could always
narrow the problem down to a particular board by swapping yours (one at a
time) with another known good card.
While the 901 Service manual may not provide specific info for this
particular problem as everyone says it is a good idea to have one anyway.
Mike - K5PU
> > From: "David" <firstname.lastname@example.org>
> > To: <Yaesu@contesting.com>
> > Date: Tue, 12 Nov 2002 19:33:41 -0500
> > Subject: [Yaesu] FT901 Noise
> > Hello and thanks for reading I have a FT-901DM With some sort of
> > self =
> > generated noise.
> > To be more specific the transmit works the recieve works, So long as
> > you =
> > recieve a signal That
> > Is over S9. constant. And of course no antenna hooked up With the
> > lack =
> > of a better description I would have to say a white noise of sorts.
> > I =
> > tried bypassing the vfo for the outboard vfo but it is still there.
> > My problem I guess is were do I start on trynig to troubleshoot this
> > =
> > problem. I do not have a service manual but do have th schematic for
> > it. =
> > Also I did remove the cards and clean the edge connectors, to no
> > avail. =
> > The S Meter reads S9 with the white noise and I do not hear any kind
> > of =
> > Hum just white noise and a signal that does not exist.
> > Thanks David KR4OW