[Elecraft] Voltage drop in DC Power to K3

[Pete Lascell]

Consider using larger stranded wire. When making connections unravel a few outside strands and cut off so the remaining strands will fit the terminals being used correctly.  The smaller (higher resistance) section of cable will be only part of an inch.  Heatshrink tubing will cover the unsightly chop job.

Depending on the exact stranding configuration of the cable, going from #10 stranded, #8 stranded is 56-64%, and #6 stranded is 37-43% the resistance of the larger #10 cable.  If going from #10 with individual strands of #26 wire to #6 cable with individual strands of #36 wire, the resistance can be as little as 35% of the larger #10 cable.  

Pete W4WWQ  


----- Original Message -----
From: Leroy Buller <lee.buller at gmail.com>
To: N4ZR <n4zr at comcast.net>
Cc: Elecraft List <elecraft at mailman.qth.net>
Sent: 4/26/2020 11:53:28 AM
Subject: Re: [Elecraft] Voltage drop in DX Power to K3
________________________________________________________________________________

40 inches of power cable.  In my experiences,  that could be an issue
depending on the gauge of the wire.  I used a long cable 12 gauge and had
issues.  Went to 24 inches number 10 gauge and voltage drop significantly
improved.  The resustace does not have to be large to cause a voltage  drop

Lee

On Sun, Apr 26, 2020, 9:47 AM N4ZR <n4zr at comcast.net> wrote:

> I've had an e-mail exchange with West Mountain Radio.  Measured the
> voltage drop inside the 4005i at only .08 volts at 100 watts key down.
> My power cable from the 4500i to the K3 measures 0.3 ohms on each
> conductor, which at 20 amps should only yield a 1.2 volt drop, right?  I
> don't know where the other volt plus of drop is coming from.  The cable
> is 40 inches long, and only minor shortening is possible.  It is about
> the largest wire that will fit in the Powerpoles on both the K3 and the
> 4005i.
>
> Suggestions welcome
>
> --
> 73, Pete N4ZR
> Check out the Reverse Beacon Network
> at <http://reversebeacon.net>, now
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> For spots, please use your favorite
> "retail" DX cluster.
>
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