Ken,
Your experience adds credence to the oft-mentioned admonition to always use
the appropriate connector on every cable, so that no adaptors or barrels are
needed. However, that is not always possible, and in your particular case
it was unavoidable. I make this statement as an observation and not as a
criticism.
Nevertheless, we must all be vigilant of the presence in the marketplace of
marginal-quality connectors and adaptors. I think we all have local
"experts" who are the first to tout "silver-plated Mil-Spec PL-259
connectors for $1 each" or "Genuine Mil-Spec RG-213 coaxial cable for just
40 cents per foot!" The fact that neither the connectors nor the cable are
produced by a supplier listed on the Qualified Product List published by
Uncle Sam never seems to be questioned by a single buyer, is troubling. I
guess too many people are eager to believe the hype, and never check the
credentials...
73, Eric Lemmon WB6FLY
----- Original Message -----
From: Ken Arck <mailto:[EMAIL PROTECTED]>
To: [email protected]
<mailto:[email protected]>
Sent: Saturday, April 19, 2008 7:51 PM
Subject: [Repeater-Builder] Bad adapter
Just thought I'd share this with everyone in case you face the same
thing.
My 2 meter machine started experiencing noticeable desense about a
week ago. No real serious weather had occurred during this time,
just
the usual Oregon rain. As I had replaced the antenna and hardline
about 2 months ago, my first thought was water infiltration.
I went to the site this afternoon (can you believe it was snowing in
April? - Damn that global warming!) and the first thing I did was
check VSWR between the duplexer and hardline feed to the antenna. 60
watts forward, zero reflected. Whew, it's probably not the antenna
or
hardline (no fun when you're dealing with an almost 200 foot tower).
The next step was to check the VSWR between the duplexer and PA.
Cool, 90 watts forward, < 1 reflected. Hmmmm, the desense is still
there. Ok, back to the duplexer output "just in case". Still the
same
- no reflected power but wait! The desense is gone! So what was
different between no Bird and the Bird in line?
As it turned out, it was an SO239 to N adapter that I had used
because I didn't have the proper stinger with me when we replaced
the
hardline. The adapter is used between the stinger (which has a PL239
on one end) and the duplexer, which is an N. And while the adapter
was a genuine Amphenol (silver plated and everything), I found out
when I got home that the center conductor connection was only
crimped
and that center conductor was cracked. Placing the Bird in line
required not using the adapter so voila!
I used another adapter I had with me and the repeater is working
great again. You better believe I'm headed back up to tomorrow with
a
proper stinger with N connectors!
Even quality can fail!
Ken
