[Elecraft] Connectors

[Don Wilhelm]

Al,

Great information!  Yes, I can agree that properly tightened UHF 
connectors do not inflict much loss.  I think the main problem has been 
with inadequate tightening - as you pointed out the shield connection 
requires that that UHF connectors be tight.  How many hams wiggle the 
PL-259 connector a bit to be certain it is seated in the notch of the 
SO-239 - this is not a casual connector for making quick connections and 
disconnections.

Where am I going with this - well, with the KPA100, we have long 
recommended "disconnect the antenna when not in use" to protect the 
wattmeter diodes from static damage.  While this is a good concept, the 
literal interpretation of that statement may actually inflict damage 
because of the way the UHF connector "connects".  With a PL-259, the 
center conductor is what makes contact first - if there is a static 
charge on that feedline, that charge will be transferred to your 
equipment without a chance to bleed it off - the only way to prevent 
that is to either short across the feedline (if there is a ground 
connection for the shield) or some other means should be used to bleed 
off the charge before attaching a feedline with a PL-259 connector to 
any equipment.  Type N and BNC do not have this problem - the shell 
makes contact first.


On 4/25/2012 7:09 PM, Alan Bloom wrote:
> (Changing to a more descriptive Subject line)
>
>
> 4.  Regarding RF loss in UHF connectors, it isn't as bad as many people
> think.  I did an Internet search and found the Usenet posting I made on
> the subject about 20 (!) years ago:
>
>