[Elecraft] normal K3 voltage drop on TX

[Edward R Cole]

I agree with Bob, but as 45-years experience has taught me.

Properly crimped bright new copper wire is fine.  Take a look several 
years later (also compare contact resistance; probably best measured 
as voltage drop under load).  If you live in the desert where 
humidity never rises above 25% you may not see any change.  Put the 
same crimped connector 100-foot from salt water and less than three 
years it will turn green and start to fail.  Put on a boat with no 
sealant and the connector will fall apart.

Solder the connector after crimping to that bright new copper wire 
and those problems will be lessened.  ON a boat only airtight sealant 
will ensure long life.  I find where I want to ensure lowest contact 
resistance soldering after crimping works.

But if the wire is subject to repeated movement or vibrational forces 
the soldered connection will break whereas crimp-only seems more 
resilient.  Spacecraft use crimped-only connectors (subject to high 
g-force vibration in launch and extreme temperature variations).  But 
then there is no air in space and thus no moisture to corrode.

For ordinary shack wiring of a ham station crimp+ solder causes no 
harm.  I use it where ever I want to ensure the lowest voltage drop under load.

Most of those NAPA wire crimpers are a poor excuse for a real tool - 
but probably what most of us use. My coax crimpers are properly 
racheting crimpers and produce a good contact.  Still I do not like 
them in situations where the cable sees a lot of movement.  Good old 
compression back nut construction is best.  I'm talking about N, BNC, 
TNC, sma, 7/16, etc.  PL-259's are used only if I have to.

73, Ed - KL7UW

----------
From: Bob McGraw - K4TAX <rmcgraw at blomand.net>
To: Jerry Moore <jermo at carolinaheli.com>, elecraft at mailman.qth.net
Subject: Re: [Elecraft] normal K3 voltage drop on TX
Message-ID: <55D7D678.80608 at blomand.net>
Content-Type: text/plain; charset=utf-8; format=flowed

Properly it must be crimped   A N  D   soldered.  Both are required.
Are you saying a crimped and soldered connection is worse than a crimped
only connection?

My military experience says there first must be a mechanical connection
made {crimp or wrap} and then follow with an electrical connection
{solder}.   And RCA stipulated this practice in all of their broadcast
equipment.

73
Bob, K4TAX
K3S s/n 10,163



73, Ed - KL7UW
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