Mark, You did not say what part of the K1 you are trying to calibrate. If it the forward power reading of the KAT1, then it should be useful within the range of its accuracy.
There are other ways to measure power and achieve good accuracy -- At the 7 watt or less power level of the K1, you can use an RF Probe connected across the dummy load, or use a 'scope with a 10X probe. That will provide you with the RF voltage level being fed to the dummy load. To calibrate the RF probe or 'scope reading - remove the KAT1 from the K1 and set the OUT menu parameter to 4 or 5 watts and do a TUNE. Note the reading on your DMM from the RF Probe or the vertical deflection on the 'scope - that is the RF voltage produced at the level indicated on the K1 display (5 watts should indicate about 14 volts with the RF Probe, or 44.7 volts peak to peak on the 'scope). The internal K1 RF detector is quite accurate as long as the load is 50 ohms pure resistive. Now you know how the RF Probe of 'scope react to that particular power level - record the voltage reading and the power indicated on the K1. Now put the KAT1 back in. (I assume you have already balanced the KAT1 wattmeter and achieved a very good null - if not, you must do that first.) With the ATU menu set for CLP, do a TUNE and tap the WPM+ or WPM- buttons to achieve the same RF voltage you had without the tuner installed. Then adjust the FWD trimmer on the KAT1 so the K1 display is the same as you had before. That method will actually be more accurate than using an external wattmeter. You are using a comparison of the indication on your RF Probe (or 'scope), so those devices do not have to be well calibrated - the only assumption you have to make is that the base K2 power indication is accurate, and I have always found that to be true after working with many K1s. 73, Don W3FPR 73, Don W3FPR On 11/9/2011 3:49 PM, Mark Flavin wrote: > Im trying to calibrate my k 1 and bought a radio shack swr bridge. With a > 50 ohm load I can tune without it but with it I get a dry high swr. I > measured the coax connectors and get a short between the two coax centers > and the grounds. It recieves ok but I can't get a decent tx reading. > Anyone know fit is just too cheap to work for this? Thanks. > > Mark. N5MF > > T-Mobile. America's First Nationwide 4G Network. > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
