[Elecraft] K3 Intermittently loses gain

[Mike Harris]

G'day,

Not having any local suppliers here forces mail order shopping for
such items as coax fittings.  Whilst there is certainly junk
aplenty, I have not been let down by the items I've bought from "The
RF Connection".  I have paid 2-3 times as much for Amphenol barrels
but not found them any better than good quality imports.  My guide
is Teflon dielectric, silver plating and mid price.  N-type, BNC and
PL259.  Crimp, clamp and solder types.  No disappointments, no
failures.

I use Ecoflex coax for my main runs and the fittings are special
size and pricy, upwards of $8 for a PL259 or N-type.

Andrew stuff can be pretty eye watering.

Regards,

Mike VP8NO

----- Original Message ----- 
From: "Jim Brown" <jim at audiosystemsgroup.com>
To: <elecraft at mailman.qth.net>
Sent: Monday, November 01, 2010 1:48 AM
Subject: Re: [Elecraft] K3 Intermittently loses gain


> On 10/30/2010 2:13 PM, Ron W3ZV wrote:
>> That leaves a couple of
>> coax connectors, a balun and the ladder line feed. Sounds like
>> the next
>> step is a quick and dirty antenna to the RX antenna input.
>
> Step #1 -- VERY IMPORTANT.  Look at every coax adapter anywhere in
> your
> station. If it does not say Amphenol on it, or if it does not have
> a UG
> number on it, THROW IT AWAY.  I'm talking barrels, Tees, Elbows,
> UHF to
> BNC, UHF to N, etc.  The unbranded connectors you buy at hamfests
> and
> from ham dealers are almost always made very cheaply, often fall
> apart,
> often go intermittent, and often overheat and fail.
>
> When I got back on the air in 2003 after a long period of
> inactivity, I
> restocked with these junk connectors, not knowing any better.
> Over the
> next several years, I experienced at nearly a dozen intermittents
> and
> failures that I eventually tracked down to one of them. REAL
> Amphenol
> connectors and adapters are one of the things I always look for at
> hamfests flea markets, but I couldn't find enough of them for my
> station, so a few years ago, I bit the bullet and bought a bunch
> of the
> real thing new from Allied.
>
> Some examples of the failures. 1) intermittent connections at the
> coax
> barrel spacing two lengths of coax feeding an antenna; 2) a Tee
> connector that came with a stacking harness for 6M antennas fell
> apart;
> 3) an elbow connecting coax to my antenna tuner overheated after
> about
> one hour of contest operation -- SWR went very high and the
> connector
> was VERY hot when I touched it because the wire inside was a tiny
> spring; 4) I've had at least four BNC to UHF or UHF to N
> connectors fall
> apart.
>
> In the world of pro audio where I made my living, we see MANY
> problems
> with junk audio connectors. The good stuff costs more to make, so
> they
> costs more to buy.  When they fail, they can cost a lot of time
> and
> trouble.  Sometimes they only cause an inconvenience, but
> sometimes they
> can cause something to break, or cause you to have to climb a
> tower to
> replace a bad one.  Bottom line -- connectors are a terrible place
> to
> play cheap.
>
> 73, Jim K9YC