Topband: Another take on power line noise hunting

[Paul Christensen]

> In the vehicle I often like to use an old (i.e. analogue and inexpensive)
> spectrum analyser like some of the portable Texscan CATV ones.

As CATV companies have transitioned from NTSC to QAM channel line-ups, high 
quality field analysis meters have been showing up on the used market in big 
numbers.  I recently acquired a used Wavetek SAM III Digital for about USD 
$100.  Another great unit is the SAM I Analog.

http://www.ham-radio.com/k6sti/sam.htm

These units are excellent for localizing power line noise, especially when 
used with a scope to replicate the noise finding method recommended  by 
Loftness and Radar Engineers.  Dual AM and FM detectors, 480 MHz standard, 
800 MHz optional, and tunes down to DC with lesser accuracy but fully 
useable for noise search.  It also has a rechargeable battery, super-rugged 
field construction and a very high quality multi-step attenuator.  A 
significant feature over other FSMs is that with a scope, it functions as a 
basic spectrum analyzer with reasonably good resolution bandwidth.  Although 
the S/A function won't help to localize power line noise, it's a handy 
feature for secondary purposes.  Not sure what these Wavetek units sold for 
new, but I would not be surprised if they were in the $2K+ area.

Paul, W9AC