[Elecraft] Grounding Strap for KPA 100

Mon May 26 01:12:04 2003

The grounding strap is connected between one of the SO-239 connector screws
and the nearest screw on the removable shield.  Gary has some fairly
elaborate straps that connects between these two points.  I just used two
ring lug connectors, one on each screw, and connected them with a #14 copper
wire.  You want to use a larger wire to minimize the inductance.  However,
something like solder braid should also work well.

The oscillation seems to occur most often on 40 meters and is due to RF
feedback between the amp and the K2 when the KPA100 is attached directly to
the K2.  If removing the KPA100 from the K2 eliminates this oscillation,
then the grounding strap will help.  It certainly won't hurt to add it on
other KPA100's that don't show this problem.

I have a picture I can directly mail to anyone who is interested in this
change.

-John
 KI6WX

----- Original Message -----
From: "Lee Buller" <[email protected]>
To: "Elecraft Reflector" <[email protected]>
Sent: Sunday, May 25, 2003 5:23 AM
Subject: [Elecraft] Grounding Strap for KPA 100

> The thread on the KPA 100 going into oscillation is an interesting one.
The cure is a grounding strap, but I have not seen any information on this
modification.  Has it been published?  Does this happen will al KPA 100s?
Can the modification be posted? Lee - K0WA
>