Phil, Thanks for that information. Mine are mounted to a heat-sink culled from a CPU cooler, and the connector is mounted to a piece of aluminum angle also affixed to the heat sink. This assembly is standalone and does not connect to any other ground plane. Although the heat sink may constitute a small ground plane, the fact that it is isolated may account for the difference in the measurement results.
BTW, I have found Caddock to be more consistent than Ohmite. Caddock advertizes their 50 ohm thick film 1% resistors as non-reactive, and the last time I looked, Ohmite did not make that statement. 73, Don W3FPR Phil & Debbie Salas wrote: > If they are mounted against a ground-plane (which is often the case for > heat-sinking), I've found that the 100-watt resistors are not too good above > 50 MHz. The 30 watt resistors are better, but the 15 watt resistors are > best thru 2-meters. I built a series of 50 ohm terminations where the > resistors were bolted to a brass plate, and the brass plate was attached to > a N-connector. The resistor leads were about 0.2" long (one pin attached to > the connector center pin, the other soldered to ground). Measured with an > AIM4170 up to 180 MHz. > > Phil - AD5X > > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
