On Wed, 23 Jan 2008 16:20:28 -0800, Jim Lux
wrote:

Actually, those Caddock MP9 and MP8 non-inductive resistors are good to
HF (allowing for the physical size). The inductance of the big ones
(MP9100, 100W units) is about 20nH, about 3 ohms at 28 MHz. Half that
for the smaller ones. The challenge is in getting the heat away from
them. the thermal resistance of the MP9100 is 1.5 degrees/W, so at
100W, the resistor is 150 degrees hotter than the heatsink, and with a
max temp of 175C, you'd better keep that heatsink at 25C.

This was covered yesterday.

73's
Richard Clark, KB7QHC