Palstar AT5K HF Antenna Tuner. Close up inspection 

Hey Art, thanks for the advice and thank you sir for stopping by.

Hey bud. I'm guessing you mean an auto tuner. So far this unit is working great. I was on 80 meters last night running about 500 watts and it was rock solid.

Hello Samuel, glad to hear from you. I hope all is well with you and the family. Well, no and yes to your question. The term "antenna tuner" is quite misleading as it does not tune the antenna but converts a mismatch of a non resonant antenna at specific frequency to 50 ohms. Ideally one would have a resonant antenna for a specific frequency span or single band operation, but for multi band operations this could become quite unfeasible as you would need a multitude of antennas to cover the entire HF spectrum. If all you are going to operate on is 1 band or a narrow band like 11m,12m, 15m, 17m, etc.. 1 antenna cut or tuned for that particular frequency is all you need. In my case I use a coaxial fed 80 meter wire loop and even if I only wanted to transmit on 80 meters, which covers huge frequency span, with the antenna length to be resonant at 3.800, venturing not to far up or down from 3.800 the SWR rises rapidly. The tuner is a very convenient way to tune out the mismatch so my transceiver will always see close to 50 ohms and I can cover the entire 80 meter band with 1 antenna. In a nut shell, you can operate on multiple bands and frequencies with 1 antenna but at the cost of loss which the tuner must dissipate. So do they trick your radio? Kind of, sort of, lol. Do they work? You bet they do! Thank you Samuel for stopping by sir!