[RFI] Ultra Sonics

[N1BUG]

Disclaimer: I was on the beta test team for the RX3.

The RX3 is a huge improvement over the RX2. I have not tested the 
RX1 but looking at the schematic I suspect the RX3 would beat it by 
a wide margin. In tests with a controlled spark source, the stock 
RX2 (predecessor to the RX3) with 12 inch dish could detect the 
spark to a distance of 35 feet. The RX3 with the same dish could 
detect it at 100+ feet.

I would definitely go with the larger dish. Actually I would prefer 
18 inch were it available. I will add that I am very disappointed in 
the quality of the dish, which I have communicated to the proprietor 
on several occasions. The detector used requires a very flat dish. 
Upgrading/modifying using one of the other dishes available on the 
market has not proven practical because they are all too deep and/or 
just just as poor in conforming to parabolic shape as the supplied 
dish. At some point when my budget allows, I plan to try a 
deeper/better/larger dish with a different detector (one having a 
wider acceptance angle or "beamwidth").

Outside the scope of your question: I would NOT use ultrasonics to 
FIND noisy poles. You want radio receivers for that. Use the 
ultrasonic to verify and find specific hardware that is sparking 
once you have located the pole.

73

-- 
Paul Kelley, N1BUG
RFI Committee chair,
Piscataquis Amateur Radio Club
http://www.k1pq.org