[ICOM] 756pro II odd behavior

[Ken Kinyon]

Hi Kevin,
There are a couple of things I would try before I opened anything up. Since
disconnecting your antenna makes the noise go away, and unplugging the cable
from the radio does also, the signal is being generated in the radio and
radiating from the cable.  I assume those cables that come with the CT-17
are shielded.  Perhaps the shield has become detached at one end, though
you'd never know, with those sealed connectors.  Try another cable or make
one out of shielded wire.  IF that doesn't do it you could take several
turns of the cable at the radio end around a ferrite toroid.  I've had good
luck with the snap open rectangular ones that radio shack sells.  However,
on the other hand, I've never heard of this before, so perhaps something in
the radio is not grounding as well as it should, for instance a loose crew
holding a circuit board in place.
In any case good luck with it.
Regards,
Ken W7TS

-------------------
Kenneth E.  Kinyon
34 Princeton Circle
Longmont, CO 80503-2106
-----------------------
E-mail: W7TS at comcast.net
------------------

> -----Original Message-----
> From: wa6fwf [mailto:wa6fwf at pacbell.net]
> Sent: Tuesday, March 01, 2005 12:01
> To: icom at mailman.qth.net
> Cc: Ken Kinyon
> Subject: Re: [ICOM] 756pro II odd behavior
>
>
> On Monday 28 February 2005 21:32, Ken Kinyon wrote:
> > Hi Kevin,
> > Do you have your radio interfaced to a computer? If so
> disconnect the
> > interface cable form the radio and see if it goes away.
> > Just a not very educated guess.
> > 73,
> > Ken W7TS
> > -------------------
> > Kenneth E.  Kinyon
> > 34 Princeton Circle
> > Longmont, CO 80503-2106
> > -----------------------
> > E-mail: W7TS at comcast.net
> > ------------------
>
> Ken,
>   for a uneducated guess you do really good...
>
> turns out its my CI-V  thats doing it,  unplugging it
> the noise is gone, changing the baud rate changes the
> width of the noise, 300 baud not heard but as you step up
> through  the speeds the width of the pulse changes with 19200
> being the
> most narrow which makes sense.
>
> The noise is there  with the computer on or off also doesn't
> matter if the
> serial cable is connected to the CI-V either.
>
>  Unplugging my ic-910 from the CI-V doesn't change anything either
>
> I'm using the cables that came with the CI-V, so it seems
> that what I am hearing
> is the 756 reporting the frequency  changes to the CI-V,
> changing the settings
> on the 756 to turn off "transceive" for CI-V also stops the noise.
>
> I have had this setup for months with no noise but I do spend
> most of my time on
> 20m and up, I will tear into the CI-V tomorrow and try and
> figure out what has changed.
>
>
> Thanks to All for the help and suggestions
>
> 73
> Kevin WA6FWF
>
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