>I learned this the hard way -- when I got back on the air in 2003 after many
>years off, I stocked up on a lot of this stuff, and spent the next 8 years
>chasing down the problems they caused me.
Same here. I'll add that it seems like a lot of hams think Teflon
dielectric represents a gold standard for UHF connectors. Amphenol
uses Teflon in a limited number of their UHF jacks and maybe some
plugs, but when I see a dielectric that _looks_ like Teflon, I become
suspicious. 1. How do hams know it is genuine Teflon and not some
white insulator? 2. A Teflon looking dielectric is often a sign of
an off-shore knockoff plug or jack. These usually have imprecise
threading and worse, jack pin cups that do not grip the male pin. A
genuine panel mount UHF jack that really has Teflon dielectric made by
Amphenol costs $10.83 from Mouser. It's nickel plated zinc with a
brass pin cup. Does this sound like a hamfest supposedly Teflon
jack? Are they $11 each at the fairgrounds? The connectors that
have a light brown dielectric use PBT polyester and cost half as much.
They are perfectly okay and can easily handle the ham power limit.
How to spot imperfect connectors before buying: Bring an Amphenol
plug and jack with you that are obviously used and not new. If you
need jacks, try plugging your PL259 into whatever you are considering
for purchase. Plug in the pin without threading on the collar. If
the pin cup fingers can grip the plug so it doesn't fall out when
hanging down it's okay. Then see if the collar can thread on easily.
Similarly use your Amphenol jack to test any plugs that are for sale.
I also learned to not trust nice looking hamfest connectors thinking
the pretty teflon/silver looking jacks had to be the ne plus ultra and
have since then had to go through my whole station dismantling various
homebrew feedline fixtures to replace them with Amphenol PBT polyester
jacks.
73
Rob
K5UJ
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|