[Elecraft] PC boards for the K2 RIT-SPLIT LED Mod

[Tom Hammond]

Bill Flynn, AI0C wrote:

>- I placed a piece of good quality black electrical tape on the
>   back side of my PCB for added protection.

OHHH DARN... ONE THING I FORGOT TO MENTION...

I forgot to note that I used a thin standoff, actually a single 4-40 split 
washer, as a spacer between my PC board the the FP board.

However, if you pre-trim all component leads as suggested in the article, 
you should not experience any problems if you choose to not use an added 
spacer.

Thanks Bill for reminding my of that omission.

>- There's a slight flicker in the LED. It is very slight, but
>   some may find it annoying so you might want to check it out
>   before drilling a hole in your front panel.

I found that the flickering helped to draw my attention to the LED.

>- I used a 910 ohm resistor instead of the 870 ohm listed in the
>   mod. The best thing to do is to divide your LED's forward
>   voltage by its rated current. For me that was 1.8V divided by
>   .002A which came out to 900 ohms.

810 Ohms yields 2.2mA

>- I used a dial caliper with a depth pin to determine the length
>   to trim the LED leads to. For my K2 it was 19/32 inch. Yours
>   may be slight different, but 19/32 or a bit more is probably a
>   good starting point.

Cut them 'long'... you can always cut them shorter.

>- Since the maximum voltage into the circuit is 4V, you can
>   safely use a 6.3VDC capacitor which is a pretty small cap
>   physically. My cap was 4mm diameter by 6 mm long and it fit
>   with plenty of room to spare.

It's the diameter of the cap, that's most important.

>- I applied some masking tape to the front panel and located my
>   lines by finding the centers of the adjacent switch holes. I
>   drilled my hold at the intersection of the two lines. Use a
>   drill press if you have one.

The bottom line drawing, if printed from the PDF, SHOULD be a 1:1 overlay. 
But of course, CHECK this BEFORE you proceed.

>- TAKE YOUR TIME. I spent most of an afternoon doing this mod
>   working slowly but surely to get it right a not mess up my K2's
>   front panel.

A word of Bill's caution is forth several pounds (Sterling) of cure!

Cheers,

Tom  N0SS