The meter itself can be off too. Using more slugs does help things, but to be really sure, test equipment needs to be periodically calibrated, which Hams never do. Dummy loads should be measured with a VNA. So, what you did is a big help, but still can't provide 100% assurance that it is accurate. I understand that is the best most Hams can do and probably better than most.
An LP-100A does come with a NIST traceable calibration from the factory and it can be recalibrated, again something Hams never do. I have one fancy scope / spectrum analyzer that I do get calibrated yearly and I use that for a reference. I have a VNA with a set of calibration standards and use that to measure attenuators / taps that I put between my transmitter and the analyzer. I admit I do not calibrate anything else, but I use the calibrated stuff as transfer standards. I also have a couple GPSDOs as frequency standards to compare to. 73, Mark W7MLG On Sat, Feb 6, 2021 at 4:55 PM Jim McCook <[email protected]> wrote: > > Good points, Ray and Jim, I should have been more detailed with what I > posted. I checked The Bird 43 with two other Bird 2500w slugs from > friends and they were all reading the same with a dummy load at 1500w. > I did the KPA1500 calibration using the Bird with a high power dummy > load, then checked again with my antennas in band segments where they > present no significant reflected power and near 1:1 SWR. At those > points they were in sync. Most of my antennas are flat on CW segments > at specific spots without using the tuner in the KPA1500. I operate 99% > CW and realize that when the load changes from 50 ohms the Bird reads > wildly high and cannot be trusted. - Jim W6YA > ______________________________________________________________ > 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 > Message delivered to [email protected] ______________________________________________________________ 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 Message delivered to [email protected]
