[Elecraft] K3 - Power cable voltage drop

[Don Wilhelm]

That would be a neat thing to do, but DO NOT do that on a power supply 
that is connected to anything other than the rig you are sensing from.

The voltage on other devices connected to the power supply will increase 
when you transmit on the rig to which the sense wires are connected.

Use a separate power supply for accessories.

If you need to use the same supply, you can adjust the voltage upward - 
the SS30 sold by Elecraft already has an output voltage of 14.1 volts.
Still use a separate power cable to the transceiver and another cable to 
any distribution box that you use for accessories for best results 
(lowest voltage drop when transmitting).

73,
Don W3FPR

On 12/24/2019 4:23 PM, K4HYJ via Elecraft wrote:
> I do use voltage sensing at the rear of the radio.  Astron supplies can be
> modified easily to do this - they already have sense wires tied to the
> voltage output terminals.  Basically you disconnect them there and run leads
> (keep em short) to the radio.  On transmit, my K3s drops less than 1/10 a
> volt.
> 
> There are a few write ups floating around on how to do this.  I installed a
> switch (make before break type) on my RS-50M so I can return to "normal"
> sensing.  ***WARNING*** If the external sense wires are not connected to
> anything the crowbar circuit will fire!!!