Towertalk
[Top] [All Lists]

Re: [TowerTalk] Crimped Electrical Connections

To: TowerTalk <towertalk@contesting.com>
Subject: Re: [TowerTalk] Crimped Electrical Connections
From: Robert Harmon <k6uj@pacbell.net>
Date: Wed, 17 Nov 2021 17:15:19 -0800
List-post: <mailto:towertalk@contesting.com>
Not much to contribute as far as crimped rotator connectors and also hope we 
don't launch into the 
crimp vs solder debate.   I am old school and only solder all electrical 
connectors and all coax connectors.  
The only failures I have had are from the space between the headphones hihi.  
Like forgetting to solder the 
center conductor on PL-259's   

73
Bob
K6UJ




> On Nov 17, 2021, at 4:43 PM, <john@kk9a.com> <john@kk9a.com> wrote:
> 
> I hate to bring up the crimp and solder debate but I crimp and solder my
> rotator terminal lugs with regular tin/lead solder. Your rotator probably
> has crimped and soldered terminals already on it. If you're connecting
> directly to a K7NV prop pitch it would be difficult to enclose the terminals
> however you could coat them with liquid tape, Scotchkote, etc.
> 
> John KK9A
> 
> 
> 
> Paul Christensen w9ac wrote:
> 
> I'm looking for input from others concerning best practices for crimping
> lugs onto solid copper wire that's exposed to the outside elements.   Here's
> why:
> 
> 
> 
> A few months ago, N4CC and I lost rotational control on one of our prop
> pitch rotators.  Our rotators are wired with #10 AWG copper Romex.  At the
> rotator, high-quality T&B copper ring lugs are crimped on the ends of the
> Romex.  A high-compression crimper is used on all connections.  Those
> connections are absolutely solid.  
> 
> 
> 
> Last week, we systematically tested the Romex at various points between our
> comm shelter and the rotator.   Each Romex wire between the tower base and
> the rotator measured an infinite open at the base on a Fluke DMM when
> shorted at the top.  It seemed impossible that #10 Romex could just fail
> open on its own.  Our first guess was that a hunter used the tower for
> target practice and severed the Romex.  
> 
> 
> 
> After installing a new section of Romex, we removed the old section, took it
> back to the shop and started looking for breaks.  None found.  Finally, I
> measured resistance between the lug's ring and the dug the other probe into
> the wire.  It still measured an infinite open.  That means all conductivity
> was lost between the lug barrel and the #10 wire.  All three lugs measure
> this way.   The lugs were crimped about six years ago and have been exposed
> to the weather.  Still, I didn't expect a well-crimped copper lug to lose
> all conduction properties.  The copper wire shows signs of black copper
> oxide which I believe is non-conductive.  And apart from creating a
> weather-proof box for the rotator connections, I'm looking for a long-term
> solution.  Frankly, I'm not keen about installing a small enclosure at the
> tower's top to protect the crimp, although it would certainly slow the rate
> of oxidation.  So that brings me to best practices.  Some possibilities:
> 
> 
> 
> 1.    Apply copper grease into the lug barrel before the crimp occurs; or
> 2.    Solder the lug after crimping, using 2% silver bearing solder
> 
> 
> 
> Comments?
> 
> 
> 
> Paul, W9AC
> 
> _______________________________________________
> 
> 
> 
> _______________________________________________
> TowerTalk mailing list
> TowerTalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk

_______________________________________________



_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk

<Prev in Thread] Current Thread [Next in Thread>