[Elecraft] KPA500 Z Bracket

[Andy Durbin]

I found the thermal clicking to be annoying and I tried to understand what caused it.  I instrumented my KPA500 with thermistors on the heat sink and on the Z bracket.  I recorded these temperatures together with the standard finals temperature over many hours of KPA500 use.

I could see that the thermal flow between the heat sink and the Z bracket changed direction and I speculated that this changing thermal gradient was causing differential expansion and contraction.  I planned to put thin mylar isolation strips between the Z bracket and heat sink and between the heat sink and the side panel.  I thought these would allow the surfaces to slip without making any noise.

However, my natural procrastination paid off and my KPA500 stopped clicking before I got round to implementing any fixes.

Andy, k3wyc