John Wiener wrote:
I just worked KJ5XF who suggested that running 50W PSK would fry the
finals. I thought 50 was about max for safe PSK.
What's the latest on this?
My KPA100 top got too hot to leave your hand on at 50W in a RTTY
contest. I put a square of sticky backed velcro on it, the mating
square on the center of a 12V muffin fan, and now the heatsink stays
cool at 90W on RTTY. I still run the K2/100 at 50W since I'm driving an
amp to 500W and need to protect it too, and at 50W, the heat sink is cold.
The heat transfer rate issue is still there ... the PA transistors will
be hotter than the HS ... but with the HS cold, the transfer rate is
increased a lot.
73,
Fred K6DGW
- Northern California Contest Club
- CU in the 2007 CQP Oct 6-7
- www.cqp.org
PS: The fan blows down onto the HS, but you all probably knew that.
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