Excerpt from Palstar BT1500A balanced antenna coupler.
I did a few Google searches for “LC Antenna Tuner” and found the best presentation on the topic yet:
It is just packed with so much useful information – and it covers the topic at a level that reminds me that I still have a lot to learn. In fact, it pulls everything that I have been thinking about into one presentation and offers the reader a way to go back to the books and study each area one at a time (which I will do).
The ARRL publications and the W8JI web site does cover some of this but not all in one place, and not in the same scope and scale as this presentation.
In just the first pass, I have learned that just having one variable capacitor and one roller inductor is fine if you are coupling / matching a limited frequency range, but that you will usually need at least three components if you want a wider range tuner. It also confirmed that there are high pass and low pass designs and that the Palstar BT1500A is a very unique coupler, and that me having it at the base is a very good decision and that for all of the low bands it does in fact seem like the right decision.
So, when someone asks “What is the best antenna tuner?” the answer is “It depends”. I also like how Larry describes what most hams call an antenna Tuner a Coupler instead.
One very important thing that I learned is that the SPE Expert 1.3K FA amplifier will be fine if I use its internal ATU in conjunction with the Palstar BT1500A at the antenna. The SPE manual says to never use the ATU with another antenna tuner – but what they don’t say is that they mean another ATU. What you don’t want at high power are two ATU’s trying to find a match and getting confused. Since I go out back and set the BT1500A manually right now – if I needed to cover more of a band using the SPE ATU I can. On 80 and 75M this would be very useful, but its a moot point on 160 and 30M since I never go more than say 20 khz across either of those bands. And since 80 and 75M are my least favorite bands, all of this is pretty much moot. Of course, if 3Y0Z miraculously bangs in on 80M, well, I will learn to love that band.
I will be reading and re-reading this presentation for some time. Its awesome. He also has a series of videos: