[Elecraft] Cable length for KPA/KAT100 remote; importance of KPA100 upgrade

[Jim Brown]

On 3/23/2012 12:21 PM, Don Wilhelm wrote:
> I don't think you will get any smoke, but if you get "strange
> happenings" - like the KPA100 is not recognized, or doesn't give a
> response back to the K2 in sufficient time (command flow over the
> AUXBUS) and things get "mixed up" or you get ERR 080, the cure will be
> to shorten the cable.

I would not expect timing problems, but parallel wire cables are recipe 
for noise and RFI problems, and making them longer makes that worse. I 
don't understand why, but Elecraft seems still not to have gotten the 
message that TWISTING is FAR more important than shielding in providing 
immunity from RFI and noise.

There are simple instructions on my website for using CAT5 cable for 
this sort of application.  
http://audiosystemsgroup.com/HamInterfacing.pdf   The specific wiring 
instructions are given for RS232 connections, and your cable is NOT, but 
if you will be in good shape if you follow the conceptual instructions 
of using one twisted pair for each signal circuit with the "colored" 
conductor used as the numbered pin and all four "white/color striped" 
conductors twisted together and tied to the connector shell.  If you 
have shielded CAT5, tie those four striped whites to the designated 
return pin and tie the shield to the connector shells.

73, Jim Brown K9YC