[CQ-Contest] Ultrasonic detector

[Steve London]

I'm sure every contester has been plagued by power line noise at one 
time or another (or all the time !).

Using a combination of HF, VHF and UHF radios, I can usually isolate the 
noise to 2 or 3 poles, but it's often hard to say which is the right 
pole, and what on the pole is causing QRN.

At my old QTH, the power company QRN technician had an ultrasonic 
detector that he could put on a hot stick (a telescoping, very insulated 
pole) to pinpoint the source of the noise.  With this device, he could 
actually pinpoint the exact offending component. I was impressed, and 
have always wanted one of my own.

I was quite excited to see the ultrasonic detector construction article 
in April QST. It looks simple enough - I should have built one years ago !

If you decide to build one, here's a money-saving tip - Using the 
promotion code FNDGFT, the shipping cost of the parabolic dish from 
Edmund Scientific is reduced from $8.50 to $0.97.

73,
Steve, N2IC