On 7/10/2013 7:42 PM, Don Wilhelm wrote:
There is one possibility that your 51 ohm load (measured at DC) is not a good 51 ohm pure resistance at the frequency you were measuring. Borrow an antenna analyzer and test your load at the frequency of operation.
There's also the simple issue of tolerance on both the resistor and the calibration of the analyzer. A 1 ohm error in a 50 ohm resistor is only 2%, and many dummy loads have a much wider tolerance. I recently went searching for calibration loads for my VNA. One rated for a watt or so with a 4% tolerance goes for hundreds of dollars.
73, Jim K9YC ______________________________________________________________ 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
