[Elecraft] AC Pole Interference

[Milt -- N5IA]

Poor connection in hot line clamps used for taps off a main line or for 
equipment connections, etc. are notorious for causing RF noise as well as 
creating fires and shock hazards in situations like Tom mentions.

Hot line clamps are used where it is not cost effective to install 
disconnect switches.

The older hot line clamps did not have spring loading, and in time, with 
wind vibration, the clamps had a tendency to loosen.

Three things have been done to mitigate this problem of burning a tensioned 
conductor in two.

1.  Hot line clamps now have spring loading.

2.  Hot line clamps typically have a dab of oxide inhibitor in the mouth of 
the clamp as it comes from the factory.

3.  Most utilities crimp install a "Saddle" loop on the conductor, and then 
connect the hot line clamp to the saddle.  Then, if the hot line clamp 
connection fails it only burns the saddle loop, and not the tensioned 
conductor.

Mis dos centavos, de Milt, N5IA

-----Original Message----- 
From: Tom W8JI
Sent: Tuesday, November 22, 2011 11:22 AM
To: Rick Dettinger ; jim at audiosystemsgroup.com
Cc: elecraft at mailman.qth.net
Subject: Re: [Elecraft] AC Pole Interference


I think the real concern is small junk falling, but after that experience
with the loose hot clamp I realized molten copper could be a problem. That
thing eventually would have burned right through the primary, and the
primary would have dropped.

73 Tom