[Elecraft] Foot Switch wiring question...

[GRANT YOUNGMAN]

I’ve never had any problem with RFI on my footswitch, running legal limit from not all that far away.  Any old shielded cable ought to do just fine — think Radio Shack quality junk.

Certainly no need for Canare in this application.


Grant NQ5T
K3 #2091, KX3 #8342




> On Mar 12, 2016, at 3:46 PM, Clay Autery <cautery at montac.com> wrote:
> 
> Hooking up a Linemaster Clipper Model No. 632-S to my K3s rear PTT RCA jack.
> 
> Obviously, the RCA is 2-conductor unbalanced and there is no issue about
> which terminals to use on the foot switch for normally open switching.
> 
> BUT, I want to make sure the foot switch cable is never an issue for RFI
> in or out.
> 
> Options:
> 
> 1) Use one-third of the Component cable assembly I built a long time ago
> with nice Canare RCA connectors and L5-CFB coax. (simply cut of one
> connector and connect the center conductor to the NO terminal and the
> braid to the C terminal) for a quick and free solution.  Kind of stiff
> with solid center conductor.
> 
> 2) Use unshielded twisted-pair 2-conductor (or shielded leaving shield
> disconnected) cable. (Have to buy a an RCA connector.)
> 
> 3) Use shielded 2-4 conductor mic cable (nice and flexible).  I think I
> have some Canare Star Quad around somewhere (Still have to buy the RCA
> connector).
> 
> My question is:
> 
> *Do I need to worry about shielding this cable?*  I've got a ground to
> pick up the shield in the foot switch, but no place to pick up a chassis
> ground cleanly in the back of the K3s...  I could terminate the shield
> to the RCA housing at the radio end, but that's going to the connector
> board...
> 
> Alternatively, I could pull the shield out of the cable near the RCA
> cable plug at sufficient length to pick up the chassis ground screw on
> the back of the chassis with a ring terminal (not clean, have to buy RCA
> connector and MAYBE the cable if I can't find my spare Canare Star Quad
> mic cable).
> 
> I'm going to use the re-purposed component cable described above for
> now, but I don't really want to EVER have to worry about this control
> cable giving me issues.  I know it's a small thing, but if I cover all
> the small things as I go along, it'll be less work to isolate problems
> if/when they crop up down the line.
> 
> Jim?
> 
> Thanks a bunch!
> 
> -- 
> ______________________
> Clay Autery, KG5LKV
> (318) 518-1389
> 
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