[RFI] Ultrasonic Dish

[N1BUG]

On 01/02/2013 06:08 PM, Hisashi T Fujinaka wrote:
>
> Thanks for all the info. That makes great sense. I've been using an MFJ
> RFI detector which gets me in the neighborhood and I need something that
> gets me closer. I was considering a hokey ultrasonic detector (I was
> going to repurpose a kid's "Spy Ear") or a ~400MHz AM receiver and a
> directional antenna at the same frequency.

I use an MFJ-856 (the one with the 3 element beam) as my primary 
location tool. To make it more useful, I added a 3 step attenuator 
and modified the unit to get the receiver out of the center of the 
yagi and clean up the yagi pattern a little. That unit alone gets me 
to 80% of the poles. In some cases there is still too much 
ambiguity. I use 445 MHz to resolve most of those down to a single 
pole. So far I've only found one case where the two units have not 
led me to a precise pole identification (135 MHz leaves too much 
ambiguity about which pole it is and 445 MHz hears nothing).

Good luck!

73,
Paul N1BUG