Hi, I highly recommend the 75W dummy load from Ridge Equipment. I have one permanently connected in my system. I believe it is a military surplus piece of equipment with absolutely superior characteristics like an SWR at 500MHz of 1.05 or less. It has no problem with 100W for a minute or less for sure.
AB2TC - Knut Phil, All dummy loads are not created equal. Connect yours directly (no coax) to the LP-100 or an antenna analyzer to determine its characteristics with frequency (I assume Larry calibrated your LP-100 to NIST standards). A common ham dummy load is something to tune your amplifier into and use for general purposes. If you are going to do measurements, you will need something more like lab quality dummy loads. Both your dummy load and the 6 feet of RG8X will show a frequency dependency since you do not have a precision 50 ohm dummy load. A transmission line that is not terminated in its characteristic impedance acts like an impedance transformer, and that transformation ratio is frequency dependent. If you want a dummy load that is flat WRT frequency and suitable for instrumentation use, take a look at the Caddock 50 ohm Thick Film Resistors - they are available up to 100 watt rating. You must use them on a heat sink, and keep the leads as short as possible, and you will have a precision dummy load. Caution - even with the heat sink, do not exceed their power ratings, they will go open circuit in an instant. I use several of those as instrumentation precision loads. Other sources of precision dummy loads is Ridge Equipment - https://www.ridgeequipment.com/store/dummyloads.html. They have one rated at 75 watts for $12 and one rated at 15 watts for $7.50 - those are quite good for instrumentation purposes. 73, Don W3FPR <snip </quote> -- View this message in context: http://elecraft.365791.n2.nabble.com/K3-LP100A-Dummy-Load-tp7119170p7120191.html Sent from the Elecraft mailing list archive at Nabble.com. ______________________________________________________________ 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
