[Elecraft] K1 RF Board Trimmer Caps

[Bruce Beford]

> My K1 RF board ceramic trimmer capacitors C13 and C20 have an outline 
> shape that differs from either that described in the K1 assembly 
> instructions or on the silkscreen outline on the RF board PCB. This is
> the same question that Dean asked back on 10/27/12. Don's answer
> described trimmer capacitors with an angular shape. This description
> perfectly describes the trimmer capacitors on the KFL1-4 filter board
> (e.g., figure 1 in KFL1-4 assembly instructions) but does not appear
> to describe the current crop of RF board trimmer caps. I didn't see
> any additional clarification associated with that thread.

Scott (and others who may be interested or wondering)

First, I no longer have my K1, so I don't have the benefit of the board in
front of me. However, some thinking, observation and measurement will lead
you to the answer you seek.

The entire goal of orienting the trimmers in a particular direction is to
insure the "rotor" of the capacitor (the part you turn) is grounded. This
way, you will not have hand (or tool) capacitance effects when adjusting
them. 

Take your ohmmeter and measure from the center, where the adjustment tool
contacts the capacitor. Measure to each of the two contacts, and find the
one that is shorted to the adjustment slot. That is the side you want to be
grounded after install. Next, look at the board, and see which hole for
either C1, C2, C5, C6, CA, CB, CE, or CH are connected to the ground plane
of the board. That is hole that you want the lead that you just identified
to end up in. The trimmers are all oriented the same way.

This will work for -any- style of trimmer if they change vendors or type.
You just need to look physically at the ones you have, and determine how the
rotor lead is identified for that particular part.

Simple, once you understand the goal.

Good luck,
Bruce, N1RX