[Elecraft] Pin 1 and Grounding Post on the K3s

[David Gilbert]

This is all very true ... especially the higher in frequency you go but 
even at HF.

One of the early jobs in my career was as the tuning diode Product 
Engineer for Motorola Semiconductor, and one of my first business trips 
was to the biggest maker of mechanical TV tuners in the U.S. I was 
trying to persuade them to convert to electronic tuning so we could sell 
them tuning diodes.  I got in a meeting with their two design engineers, 
who were almost three times older than me and at least three times 
smarter.  They pulled out some of their mechanical tuners and explained 
how they worked and what some of the advantages were versus electronic 
tuning (and there are some).

The thing that really got my attention was when they explained how they 
managed the coupling between the RF, Mixer, and Oscillator stages.  They 
would literally adjust some of the coupling by directing the flow of the 
eddy currents in the walls of the stage shielding ... which of course 
was all "grounded".  One of the guys pointed to a couple of punched out 
slots in one of the side walls and told me he did that to make more of 
the eddy current go where he wanted it to go.

These guys were artists as much as they were engineers, but it certainly 
taught me that, as you say, "where there is metal there is resistance, 
and where there is current there is voltage" ... and I will add that 
where there is current there are fields.  Fields that can couple to 
other bits of metal.

73,
Dave   AB7E



On 6/24/2021 12:49 PM, Hal Massey wrote:
> Fixing a common misconception about grounding…
>
>
> Grounding does not get all the devices at the same potential. It just minimizes the potential difference among them. “Where there is metal there is resistance and if there is any current there will be a voltage (period).
>
> This is one of the biggest urban myths around and the source of many difficulties for lay folks trying to understand grounding. -BSEE and MSEE here.
>
> A practical application of this for hams is to keep the runs short and low inductance too!
>
> 73
>