Many hams use various Auto-Tuners to couple their transceiver to their antenna system. The amateur radio marketed Auto-Tuners use microprocessors to supervise the matching process, maintain remember settings in their memories, and in trying to minimize damages from errors.
The basics behind the electronics is the same – things are changed to provide the correct values to make the mismatched electrically appear as matched – or “coupled” in the historic sense – to the transceiver.
The Auto-Tuner may “sample” the transceiver’s signal to get an idea of where in the amateur bands the operations are, or the Auto-Tuner may track the band changes through any number of methods.
Works great and at the K9ZW shacks I usually use either the Palstar or Kessler versions of the AT-AUTO. Through a legal process Kessler is the source for things AT-AUTO and their website can be found at https://kesslerengineeringllc.com/tuners.html
I had a Palstar AT-AUTO long before the legal battle that resulted in the AT-AUTO becoming a Kessler and I’ve bought more since. Palstart has a redesigned HF-AUTO unit who friends report is excellent – http://www.palstar.com/en/hf-auto/ – though I’ve not updated to the new unit. I was distracted by the aborted Alpha-4040 tuner shown at Dayton but which never made it to production.
Having been blessed with natural matches on all but 80 m and 160 m at my recently dismantled home QTH station, an antenna tuner was hardly a priority.
Will also tell that I am looking forward to the upcoming 4o3a Tuner Genius antenna tuner, which should integrate nicely with my other 4o3a gear.
But what happens if things don’t tune well and your Auto-Tuner doesn’t auto-tune anymore?
Here at the K9ZW shacks I have manual tuners with jumpers on the ready. The K9ZW Island QTH has a manual Palstar and a further old-style Dentron ready to patch in.
At the K9ZW Work QTH I have a Murch manual tuner, but as the Flex-6600M has an internal tuner and I’m running that station barefoot I doubt it will be needed.
For the K9ZW Main QTH at my home I have a small collection of Dentron RT-3000 and Murch manual tuners on the ready.
What the Dentron RT-3000 and Murch share is they are solidly constructed robust basic tuners with solid performance figures. They have repeat-ability to return to the same match by simply dialing them in. They are NOT calibrated against each other of course. So you can’t swap one out and plug in another using the same dial settings.
Have enough back-up units to jumper in one per feedline as they come into the shack if need be, as unlike the Auto-Tuners they back up, these manual tuners are not agile in following band switching.
Some reasons to have an auto-tuner backup beyond the day where the auto-tuner doesn’t turn on, is that in certain instances the sensing system in an auto-tuner may end up confused by otherwise acceptable conditions. I’ve seen this in icing weather where the automatic kept searching and changing as the conditions changed. When I switched to manual that tuner settled down and after a few minutes of operations whatever was reflecting a detectable amount of power back to introduce sensor confusion disappeared.
While you might not want to do a comprehensive backup like my example, you might think if you should have a decent manual backup if your auto-tuner doesn’t tune.