[Elecraft] K3 Intermittently loses gain

[Jim Brown]

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