A good one that you know is 50 ohms over the range of frequencies and power you want to use it at. Unfortunately, any particular model may be good or bad, depending on how it has been used or abused. Is there any way you can get access to an analyzer to determine if the dummy load is good? I have a Vector Network Analyzer, but few hams will have one of those.
Also, if you really want to do a real calibration, you should have a calibrated reference to check against. Lots of devices can be 5-10% off if not calibrated, worse if abused or damaged. A Bird meter is only specified to I think 5% of the full scale. So if it is a 200W full scale, it could be 10W off. So 100W might read 110W or 90W. I've got a calibrated Spectrum Analyzer and Signal Generator that I use to calibrate all my other stuff against, but again, few Hams will have similar or spend to keep them in calibration. In general, oil filled dummy loads with fins like the Birds shown lower on this page are going to be good, but expensive: https://www.birdrf.com/Products/Test%20and%20Measurement/Loads/Coaxial-Terminations.aspx You can find similar ones used, hopefully not abused and not filled with PCBs. I've got a similar one that must be decades old and it works well and is pretty close to 50 ohms over the HF range. I have not opened it to see what it is filled with! 73, Mark W7MLG On Sat, Aug 25, 2018 at 4:09 PM, Steve Lawrence via Elecraft < [email protected]> wrote: > What are recommended dummy loads to consider for use when running the K3 > TX Calibration? > > Thanks - Steve WB6RSE > ______________________________________________________________ > 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]
