[Elecraft] Voltage drop in DX Power to K3

[Bob McGraw K4TAX]

The power cable at 0.03 ohms on each side,  a total of 0.06 ohms 
resistance.  The 4005i, per his measurements, has 0.08 ohms 
resistance.   The power distribution strip contributes more than 50% of 
the voltage drop.   Actually more than the power cables.

The power cable contributes  1.2 volts of drop.   The 4005i contributes 
an added 1.6 volts of drop for a total of 2.8 volts.

The calculation is simple:    E = I x R      current multiplied by amps 
equal voltage.

73

Bob, K4TAX



On 4/26/2020 10:53 AM, Leroy Buller wrote:
> 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
>> spotting RTTY activity worldwide.
>> For spots, please use your favorite
>> "retail" DX cluster.
>>
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:Elecraft at mailman.qth.net
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>> Message delivered to lee.buller at gmail.com
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Elecraft at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to rmcgraw at blomand.net
>