Alan,
I recently installed a new Garmin 200 into my panel and I ran my coax across my
FP-5 fuel flow and on certain frequencies 134 and up the FP-5 was a light show
and finally went blank. If your trim indicator is in the panel, rerouting
the com may help, shielding the trim indicator, if nearby the radio may be an
area to look at if the coil doesn't work.
Finally, if you run your com coax on the same side as the 5 wire trim bundle,
that
has caused problems before.
As Jim said, ferrites can work but there may still be certain frequencies that
interfere. A Faraday box does work. You don't need Mu metal as there isn't a
lot of magnetic flux in the coax. That said, I have one of the old style needle
type Mac trim indicators and it can be fluctuated by high current ops or the
nearby new Garmin Com radio to my surprise.
Keep plugging away.
Bud Yerly
-----Original Message-----
From: owner-europa-list-server@matronics.com
<owner-europa-list-server@matronics.com>
On Behalf Of Alan Twigg
Sent: Saturday, June 12, 2021 11:01 AM
Subject: Re: Europa-List: Re: G-GIWT air tests
Thanks Jim, I put an antenna behind the cockpit in the roof, the ferrite sleeve
seems to have fixed the problem, tommorrow I will fly to prove it.
Alan
Sent from my iPhone
> On 12 Jun 2021, at 15:29, h&jeuropa <butcher43@att.net> wrote:
>
>
> Alan,
> The trim motor is located very close to the comm antenna if your antenna is
> located
in the rudder flange per the manual. If the comm antenna is not well tuned,
there may be excessive radiation from it that interferes with the trim motor.
I'd suggest you check the standing wave ratio (SWR) of the comm antenna
at different frequencies.
>
> You might try wrapping the trim motor in conductive foil (aluminum foil) to
> see
if shielding it solves the problem.
>
> Ferrite sleeves often do not solve the problem as they are not universal and
the ones that are readily available are not correct for our VHF frequencies.
I tried a lot of ferrite sleeves when I had my Blue Mountain EFIS trying to
solve
problems with very little success.
>
> Jim
>
>
>
>
> Read this topic online here:
>
> https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fforums.matronics.com%2Fviewtopic.php%3Fp%3D502344%23502344&data=04%7C01%7C%7Cf81d5bfdcc07466d0eff08d92db3a3f3%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C637591071834005806%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=HtKN5tPSut76HRtU7shin%2Fd8xkoVsuIPfk0o8Xqx8Cg%3D&reserved=0
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