[Elecraft] normal K3 voltage drop on TX

[Jerry Moore]

Nice NASA geek type reading on connections and such. I'm sure the
information is largely out of date but still has a ton of really good info. 

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19750010203.pdf



-----Original Message-----
From: Elecraft [mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Edward
R Cole
Sent: Saturday, August 22, 2015 2:03 AM
To: Elecraft at mailman.qth.net
Subject: Re: [Elecraft] normal K3 voltage drop on TX

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
http://www.kl7uw.com
     "Kits made by KL7UW"
Dubus Mag business:
     dubususa at gmail.com

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