[Elecraft] KPA/100 RF cable

[Tom Hammond NØSS]

Hi Benjy:

>I'm getting ready to make the RF cable that connects to J1 of
>the KPA/100 and connects to the Aux RF connector on the K2.
>
>The instructions say to remove 3/4" of the coax jacket from both
>ends.  Crimp connectors are soldered to one end of the coax and
>the other end goes to the board.  But, surely, the end that gets
>soldered to the board should be trimmed down from the 3/4".
>Otherwise, you'd have about 1/2" of exposed braid above the
>board.  So, can I assume that the folks who wrote the manual
>thought that it was obvious to trim the board end of the coax
>down a bit?

The very LAST thing you want to risk is having one (or more) of the fine 
shield wire strands short out against something else... as a result, it's 
safest to keep the point where the shield separates from the coax a bit 
removed from the board.

The way I handled my cable was to separate the wires as instructed. Then, I 
cut the shield to about 1/4" long, twisted it, and (quickly) tinned it. I 
then folded it back against the outer insulation of the RG-174 and (again, 
quickly) soldered a 1" length of flexible length of #20 insulated hookup 
wire to the shield. I then covered this connection (around both the 
connection AND the RG-174 itself) with a short length of heatshrink, 
allowing the hookup wire ground lead and the center of the RG-174 to extend 
well past the heatshrink. Then I cut the ground lead to length, stripped 
and tinned both leads and installed.

>Also, is there any advantage to making the cable a little longer for when 
>you have the top open for testing?

NOT recommended.

Tom  N0SS