On 10 Sep 2011 18:27:58 GMT, dave wrote:

Cell sites are a different animal . We were talking about 2-way,
point-to-point, VHF/UHF broadcast type sites.

Perhaps you didn't notice but several of the examples of PIM and
rotten coax induced intermod were for non-cellular systems. The
problems are much the same with any service type. If you have
moderate TX power, magnetic materials in the connectors, and sensitive
receivers, PIM might be a concern.

Also, it may not be obvious unless you've worked on a cell site, but
the state-o-de-art in radio is currently defined by cellular. The
current generation of cellular radios, pre-distorting power amps,
tower mounted amps, cryogenic front ends, steerable antennas, channel
loading, codecs, and environmental protections, are far superior to
what I've seen in commercial radio, and light years ahead of the 3rd
hand garbage commonly found in ham repeaters. Yes, cellular is
different, but it's also quite superior. If the cellular people think
they have a PIM problem, it's probably quite real.

Unfortunately, cellular can't always get everything right:
http://802.11junk.com/jeffl/SCCARC-talk-2010-06-18/Burning-Towers.htm
http://www.cellsiteanalysis.net/cell_site_analysis_images/Cell_Site_Mast_Loaded.jpg

YouTube is pretty intense.

Duz that mean that you still haven't watched the video clip?

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558