[Elecraft] K3 Voltage on TX

[Bob McGraw - K4TAX]

Well my take.....ANYTHING between the power source and radio has 
resistance, regardless of how small.  Resistance with any amount of 
current equals voltage drop.  Thus E = IR   Where E is the voltage drop, 
I is the current and R is the resistance.

I'm not sure what some of those thing are nor why they are needed but I 
do know least is best.  As to operating from batteries, floating AGM 
batteries at 13.8 should not produce any voltage drop other than the 
resistance of the power cable.    Of course a fuse or switch in line 
does have R so there goes the regulation as current changes.  Nothing is 
better than a good regulated supply and hopefully one with remote 
voltage sensing.   Of course those are more expensive and more of a 
challenge to install and then have operate correctly in the presence of 
a RF field.

73
Bob, K4TAX
K3S s.n. 10163
  

On 10/26/2015 3:55 PM, Bill Frantz wrote:
> I gave up running my K3 through a RigRunner for just that reason. I 
> put in a short lead directly to the battery bank APP junction strip 
> and things got a lot better. They got even better with a N8XJK Boost 
> Regulator between the K3 and the junction. (Tested with 100W into a 
> dummy load.)
>
> 73 Bill AE6JV
>
> On 10/26/15 at 12:50 PM, jim at audiosystemsgroup.com (Jim Brown) wrote:
>
>> On Mon,10/26/2015 12:37 PM, Bob McGraw - K4TAX wrote:
>>> In fact, anything in line between the power supply and radio can 
>>> contribute to this.  Even fuses, switches, power connectors and 
>>> such.  Any connection that is loose or terminal that is loose will 
>>> be a voltage drop point.  They just add up.
>>
>> Yes. I've been told that the DC bus in popular DC distribution strips 
>> is quite small considering the rated current. They're fine for 
>> accessories that don't draw much current, but don't run your rig 
>> through them (unless it's QRP)!