Jeff Liebermann wrote:

On Sun, 06 Dec 2009 22:51:17 -0500, "Michael A. Terrell"
wrote:

Part of the extra .5 dB loss is in the cast aluminum 'F' connectors.
I ran Q. A. I ran tests on hundreds of samples to qualify them for our
MSO to purchase the best quality we could find. We bought splitters by
the thousands, and coax by the pallet

Also, eight way splitters are listed at -10 dB, not 10.5.

Agreed. However, I never had much trouble with the aluminium F
connectors. It was the chrome plated zinc castings that drove me
nuts. The RF skin depth at 1GHz was terrible making the connectors
rather lossy. Combined with an aluminum F connector, I had a few
millivolts of electrolysis and noise.


the tap plates were cast aluminum if they were Jerrold, or plated
brass threads bolted to an aluminum plate in Lindsay taps. Both cause
problems in areas where road salt was used. Just as bad were the
unplated brass cable connectors someone tried to sell us.

For entertainment, I like to string all the adapters in my collection
in series, and measure the loss. According to numerous luminaries,
the attenuation would be attrocious, sky high, dismal, or anything
except nominal. I don't have photos of my last song and dance in
front of the local radio clubs, but one person agreed to reproduce the
experiment with decent test equipment:
http://802.11junk.com/jeffl/antennas/connector-loss/


Run the tests again after a 48 hour salt spray test.


The display photos are rather difficult to read. The loss through
about 20 adapters is about -0.3dB at 450MHz and -2.0dB at 2.4GHz.
That's approximately the loss of an equivalent length of LMR-240. I've
done similar tests with assorted F adapters with similar results. The
chain a created for the local radio clubs was about 6ft long. I got
lazy and just used a wattmeter at each end of the coax, and a handheld
radio. Hardly any loss at 446MHz.


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