I decided to measure the impedances in a typical #hamradio #antenna setup with an unmatched antenna, here simulated by a 270R resistor.

At 3.5MHz, the feeder (25m H155) transforms this to 30+j51 ohms. Using the #nanovna_v2, I adjusted the tuner to a 50 ohm match at the tuner input.
Terminating the tuner input with 50 ohm, I removed the feeder and measured into the tuner output. I got (almost) the exact conjugate: 33-j53 ohm 👍🏼🙂
So the tuner presents a capacitive conjugate to match the inductive part of the impedance presented by the feeder.

That’s all there is to it: the antenna tuner doesn’t ’tune the antenna’, it creates a decent match to the transceiver while presenting a complex-conjugate to whichever impedance is presented by the end of the feeder, thereby securing maximum power transfer 🙂

#testandmeasurement #antennatuner #antennabuilding #hamr #mfjenterprises #rohdeschwarz

By now you've probably seen the news that #MFJEnterprises, a staple in the #hamradio community, is shuttering its US manufacturing operations. This is indeed sad news. Like most #amateurradio operators, I have many MFJ products in my shack--including a 50-year old audio CW filter I bought when I first got started. They will be missed, but there is a larger point to be made.

https://mailchi.mp/62e24f2ccc99/a-heavy-sad-heart

MFJ ceases on-site production in Starkville, Mississippi

https://swling.com/blog/2024/04/mfj-ceases-on-site-production-in-starkville-mississippi/

#MartinJue #MFJ #MFJEnterprises