StrikeFinder Problem

[Jonathan Goodish]

I had an Insight StrikeFinder installed several years ago, and it always
worked well, detecting nearly zero electrical interference from the
aircraft in flight. The StrikeFinder is on a push-pull breaker, and
over the winter I normally kept it unpowered, primarily because I didn't
need it, but also because of concerns with the life of the gas plasma
display (Insight has since told me that not powering the unit could be
worse for the display than having it lit continuously.)

In any case, I've now started to power the unit in flight again, and it
is painting a solid line directly off the nose of the aircraft almost
immediately. Clear the display, and the line comes back within a minute
or two.

About 6 months ago, I had my alternator replaced with an overhauled unit
to cure alternator whine through the audio system, and that plan mostly
worked. This is the only change to the electrical system that I've
made, and given the location of the noise the StrikeFinder is painting,
I'm guessing that's the problem. During the alternator replacement,
there was a new grounding strap fabricated and applied between the
alternator and the engine. The alternator has a new filter cap on the
output, shunted to ground on the alternator case. As a mentioned, this
alternator basically cleaned up the audible whine that I had with my
previous unit, which did not cause electrical interference with the
StrikeFinder (but did produce an annoying whine in the audio system).

Insight is telling me that the only solution to my problem, if it is the
alternator, is to replace the alternator. Needless to say, I don't want
to keep swapping alternators endlessly. Does anyone have any experience
or suggestions?


Thanks,
JKG

[Dave[_16_]]

Jonathan Goodish wrote:
> I had an Insight StrikeFinder installed several years ago, and it always
> worked well, detecting nearly zero electrical interference from the
> aircraft in flight. The StrikeFinder is on a push-pull breaker, and
> over the winter I normally kept it unpowered, primarily because I didn't
> need it, but also because of concerns with the life of the gas plasma
> display (Insight has since told me that not powering the unit could be
> worse for the display than having it lit continuously.)
>
> In any case, I've now started to power the unit in flight again, and it
> is painting a solid line directly off the nose of the aircraft almost
> immediately. Clear the display, and the line comes back within a minute
> or two.
>
> About 6 months ago, I had my alternator replaced with an overhauled unit
> to cure alternator whine through the audio system, and that plan mostly
> worked. This is the only change to the electrical system that I've
> made, and given the location of the noise the StrikeFinder is painting,
> I'm guessing that's the problem. During the alternator replacement,
> there was a new grounding strap fabricated and applied between the
> alternator and the engine. The alternator has a new filter cap on the
> output, shunted to ground on the alternator case. As a mentioned, this
> alternator basically cleaned up the audible whine that I had with my
> previous unit, which did not cause electrical interference with the
> StrikeFinder (but did produce an annoying whine in the audio system).
>
> Insight is telling me that the only solution to my problem, if it is the
> alternator, is to replace the alternator. Needless to say, I don't want
> to keep swapping alternators endlessly. Does anyone have any experience
> or suggestions?
>
>
> Thanks,
> JKG

Why not disable your alternator and see what the strikefinder shows?

Does it do it on the ground with the engine off?

It could be other pieces of equipment that may be causing this problem.
Have you tried to shut everything else off and leave only the
Strikefinder on?

[Montblack]

("Dave" wrote)
> Have you tried to shut everything else off and leave only the Strikefinder
> on?


http://www.youtube.com/watch?v=aJFBuJu97kw
Maybe.... The Final Countdown (1980) storm is following him around.

It's either that or a ground somewhere. Why an iffy ground as culprit?

It's all I know how to do when diagnosing electrical problems. Plus, on
these groups, that solution has recorded a 63% success rate.


Paul-Mont

[RST Engineering]

Have you ever seen an arc welder when the ground lead isn't making good
contact? There is as much arcing at the ground clip as at the work rod.
Think of it as one continuous little tiny lightning bolt at close proximity
to the antenna. Since signals drop off as the square of the distance, and
figuring that the ground arc is about five or six feet (let's say six) from
the antenna and the Strikefinder has a range of somewhere around 200 miles,
we can say that the ratio of six feet to 200 miles is about 176,000:1.
176,000^2 is somewhere around 31 BILLION:1, so to produce a readable signal,
that arc only has to be one 31 billionth as strong as a lightning bolt which
ain't a difficult thing to do.

k?

Jim

>
> It's either that or a ground somewhere. Why an iffy ground as culprit?
>

[Montblack]

("RST Engineering" wrote)
> ....so to produce a readable signal, that arc only has to be one 31
> billionth as strong as a lightning bolt which ain't a difficult thing to
> do.


http://www.answers.com/topic/ernststavroblofeld-jpg
So no more silk suits and cats in the cockpit. Problem solved.

(NAC) Necessary Aviation Content ....movie poster
http://www.answers.com/topic/007yoltposter-jpg

http://www.bbc.co.uk/norfolk/your/extra/science_week/you_only.shtml
More fun from the movie

http://www.rotaryaction.com/y.html
And one more :-)


Paul-Mont