Re: Going on an Antenna Hunt (was: RF interference issue again (esp. for E Drucker and Jim Weir and other RF wizards)

Mark Mallory <[EMAIL PROTECTED]> wrote in message news:<[EMAIL PROTECTED]>...

> >>->If I drive to the antenna farm and get the interference,
> >>->does it prove the problem is outside my plane, or just that
> >>->the handheld is also more susceptible to it?

> It could mean: 
> The antenna farm is clean; the handheld and your plane *both* have a problem.

Or, the handheld *is* the problem, since it's normally in the plane?
(but normally disconnected from its antenna)

> The antenna farm has a problem; the handheld *may* be clean and 
> your plane *may* be clean.

> Since you don't have enough information to distinguish between the above >cases, 
> you can't rule your plane IN or OUT.  On the other hand, if you HADN'T gotten 
> the interference on the ground with the handheld, you could probably rule the 
> plane IN (but still not conclusively if the problem is intermittent.)

> Isn't troubleshooting fun?  ;^)

Just Ducky (pun intended).  

So what do you suggest to distinguish?

My ideas are:
1) return to antenna farm w/ handheld and try to stay long enough
   to get a station ID, also confirm lat long coordinates
   if interference received:
2) fly w/out handheld in the plane
   if interference received:
3) remove #2 nav com and ELT from plane
   fly again
   if no interference:
4) put one back

I called the FSDO last week and got the name of their frequency
guy, talked to him.  If the problem reproduces today and I have
the street address and lat-long of the antenna, I'll call him back
with an update since "go right here and see what you find" is
an easier proposition than "there's a problem somewhere in this
vicinity"

I'm also thinking it might be worth a call to the TV station,
to see if they have someone who cares because maybe they have
better equipment and could check this out.  (or maybe I can get
the FAA guy to call...)

> You mentioned the problem was considerably worse on *one* com than the > other... 
> if the problem IS in the plane, that's my guess as to the source (see my other 
> post).  Can you disconnect the antenna from *that* com, and fly with just the 
> other one?

No problem, but it would be easier (as well as owner-allowed maintenance)
to just remove the radio -- if that would suffice?  Or are you thinking
it's the antenna/cable?

IF it's the radio -- unfortunately it's a TKM.  Are there bench
checks our local avionics guy should be able to run to see if it's
up to spec, before we ship it out to them?

Thanks!
Sydney