Watch out for the UHF elbow adapters as well. Some are so poorly made
they may arc internally to the shell.
It depends on the quality of the UHF series connectors as to how much
loss. A number of years ago, I had a client who decided to set up
his own two-way radio test bench. For some reason, he used PL-259
and PL-258 connectors from Radio Shack. He also, for some unknown
reason, had a total of 7-connectors in less than 10-feet of RG8/U
plus a dummy load and a Bird 43 wattmeter.
The first units he checked had a specified output of 35-watts in the
450 MHz to 470 MHz range. He was reading well under 10-watts on his
Bird 43. The client telephoned me wanting to know why such a low
reading. I took my Bird 6154 dummy load / wattmeter with my coax
jumper over to the client's office. With the Bird 6154, the
transmitters registered over 35-watts output. Then, I used his
cable, including all the Radio Shack connectors, to feed the 6154.
The power registered the same as with the client's wattmeter.
I started removing sections of jumper cable from the client's setup
and the reading on the 6154 kept increasing. Next, the jumper cable
from the 6154 was used with the client's wattmeter. A full 35-watts
was read on his wattmeter.
Further examination showed right at a 1 dB loss in each of the Radio
Shack connectors! I did not check the connectors at lower
frequencies. The client replaced his jumper cables with a single
piece of RG8/U with Amphenol PL-259 connectors at each end and his
wattmeter read over 35-watts.
After that experience, I definitely avoid using Radio Shack
connectors. I don't know if the particular "batch" had problems or
what. But, the price of Radio Shack connectors usually is right at,
and sometimes even more, than quality connectors. As such, I don't
take a chance and stay clear of Radio Shack where r.f. connectors are
concerned.
Glen, K9STH
--
Thanks! & 73, KD4E.com
David Colburn - Nevils, Georgia USA
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