[RFI] New RFI source for me...

Dave Cole dave at nk7z.net
Sun Jul 24 12:18:26 EDT 2016

On Sun, 2016-07-24 at 11:36 -0400, Frank N. Haas KB4T wrote:
> I will not speculate as to what the source might be. As I have said in
> this
> forum many times, I consider such attempts to be a complete waste of
> time.
> However, I will say that the periodic character of the source should
> make
> it easier to find. If the highest frequency at which this source can
> be
> detected at your location is 4.0 MHz, options are limited. The first
> tool I
> would use is a battery operated receiver and the National RF HFDF
> Vector
> Gun active loop antenna kit.
> You don't describe the antenna or radio equipment being used to hear
> the
> source. You also don't describe the  relative signal strength though
> from
> the audio recording it would seem that the source is fairly strong. It
> may
> be difficult to hear the source on any portable receiving system. If
> so,
> you may have to perform an expanding circle or square search to find a
> location where you can hear the source well enough to begin
> pinpointing it.
> I have been faced with this kind of source many times over my RFI
> investigation career. Patience, good record keeping, more patience and
> an
> open mind are essential.
> Don't waste time trying to guess what this source might be. Find it.
> Then
> report your findings.
> Each time one is involved in a search of this sort, the experience is
> valuable, educational and, when successful, very satisfying.
> Good luck and good hunting.
> Frank N. Haas KB4T
> Utility RFI Investigator
> Florida

Hi Frank,
I will be doing exactly as you described as soon as my part arrives from
Tarheel, the low band antenna for the truck is dead at the moment...I am
just trying to get a feel for it is all and hoping someone had heard
this sort of signal at some point. 

To your point about equipment-- K3, and a Gap Vertical.  I already tried
with a portable SW reciever, and you are correct, not strong enough. 

The signal is about S7, or -90db at the antenna here.

You mentioned the National RF HFDF Vector Gun active loop antenna kit,
is it much better or worse than an Alex loop?  I have been looking at
that for a while now, and considering building one, but with summer
coming to an end soon here, I might get it if it really works.  Could
you comment on it please?  

73's, and thanks,
Dave (NK7Z)
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