doc wrote:
>What about using one of the parabolic mic gadgets that one
>sees in the catalogs now and then.
>
>Should only require limited mods.
>
>doc
>
Hi, Doc--
Looked at those and most looked like toys -- dish way too small for
what I want to do. I would like to find a clear-plastic dish about
18-24 inches in diameter, and most of the toy directional mics
(bird calls, etc) use what looks like a 6 inch dish.
And I THINK I want to listen to the actual noise, rather than just
read it out on a meter, so instead of just needing an amplifier I
would need some sort of downconverter to move the ultrasonic
noise into the audible range.
Granted, I am just doing this as a preliminary mental exercise at
this point, so that is why I would love to see some details. Our
local REA office is a small branch of the main company and even the
main company does not have much in the way of tools. So I thought
I could help them out. When I bought this place it was VERY quiet.
In fact I could take my Sony SW radio and put the antenna within
1/2 inch of the ground wire coming down the pole before I could
hear ANY power line noise. But we do get a lot of lighting and
there is now a pretty strong noise on the AM band when I drive under
the power lines on the road. We are in a VERY rural area with
power lines few and far between and the next set of power lines
is about 1 mile up the road and it also seems to have the same, new
noise. Listening on my little 20M vertical shows that the bands are still
fairly quiet but not as quiet before. And once I get up some serious
antennas for both HF and VHF/UHF I figure I may need to do a
little RFI detection. Presently I have a 6L 450 Yagi mounted on a
gun stock that was used to test scopes. It looks pretty slick and
professional, so I figure I need to make an ultrasonic device that
works really well AND looks nice! But then I love to make good
looking home brew projects. My next generation 450 locator
will have the Yagi mounted above a .30-.30 so I can detect AND
ELIMINATE noise sources myself! ;-)
73 John W0UN
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