I've been pricing scanners and the last post seems to point out the rub:

The source of transmission must be within 300 feet, making the scanner good only for the pits area and frequency control to help prevent two radios from being turned on at the same time. It does not look like it's designed to scan for interfereance from other sources, such as pager towers, etc. that are not within your "300 foot area".

Not bad for the price for the pits area - put it up by the transmitter impound or have one for a last check - it's very cheap. But the Icom wide band receivers (at about $250+) are really the only thing I've found to date that will give you a better picture of the active frequency spectrum and signal strengths of sources at your position around your 72mHz channels.

There was another guy selling a device more suited that showed strength of the signal source only on 72 mHz channels, but he was out of production at the time (Wolf something?).

Anybody got any other product's capability/suggestions?