[Elecraft] KPA500 Clicking Noise

[Dana Roode K6NR]

I hadn't used my KPA500 for awhile, but I put it on the air recently.  It's
working fine with my K3, but after it warms up - 40 degrees C or so - I
start to hear a faint clicking noise.  It is coming from the vicinity of
the fan and heat sinks.  There is a click every 10 seconds or so, I think
whether I am transmitting or not.  Fan control is working fine, and I
bumped up the lowest speed to help keep the amp cooler.

Let me know if anyone has seen this before.  Meanwhile, I will keep using
it and see how it goes.

  Dana, K6NR