[Elecraft] K3 - Power cable voltage drop

[K9MA]

Typically, there are small resistors at the power supply between the output and sense terminals to prevent the voltage from rising if a sense wire opens up. 

73,
Scott K9MA 

----------

Scott Ellington

 --- via iPad

> On Dec 24, 2019, at 5:39 PM, Bob McGraw K4TAX <rmcgraw at blomand.net> wrote:
> 
> Yes, but one screw-up on the remote sensing system and it will take advantage of the voltage overhead on the pass transistors and likely wipe out every piece of equipment.       I strongly do not advise it.   And you make a valid point for NOT using remote sensing.
> 
> 73
> 
> Bob, K4TAX
> 
>> On 12/24/2019 3:22 PM, Jim Rhodes wrote:
>> I have thought about doing that. Just requires a 2 wire hookup with small
>> gauge wire. But I run all of my small items like the remoterig box, LP-pan
>> box, VHF/UHF rig and so forth off of the main supply and if I have a larger
>> than anticipated voltage drop on rig power cable the voltage on the other
>> tings could go fairly high. The power supply is a HB thing with at least a
>> 50 amp capacity and plenty of voltage overhead before pass transistors.
>> (Used to run 2 HF rigs before downsizing.)
>> 
>> 
>>> On Tue, Dec 24, 2019 at 2:25 PM Rose <elecraftcovers at gmail.com> wrote:
>>> 
>>> First, it would require some basic technical skill ... (;-)
>>> 
>>> 73
>>> 
>>> K0PP
>>> 
>>> On Tue, Dec 24, 2019, 13:20 Karin Johnson <karinann at tampabay.rr.com>
>>> wrote:
>>> 
>>>> Why hasn't anyone used remote sensing at the radio voltage input?
>>>> As far as I know all of the Astron supplies don't have external sense
>>>> wiring.  Many so called professional grade high current supplies provide
>>>> For external connection of the voltage sense back to the regulator chip.
>>>> I've toyed with this idea a bit but haven't had the time dig in to the
>>>> Astron supply I have.  If this were implemented then one could maintain
>>>> 13.8 volts or whatever you desired at the radio power supply inputs,
>>>> Regardless of the current draw.
>>>> 
>>>> Karin Anne Johnson K3UU
>>>> 
>>>> 
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> 
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