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Quite an interesting discussion... At work a couple of years ago, I built an autotuner to match a PA to a coil/antenna in an NQR (nuclear quadrature resonance) "substance" detection system, which

A very valid point but with the computing capability inherent in these suggestions, perhaps a calibration map of the actual Ls and Cs would resolve the difficulty? 73 DE G4SDW

Interesting… those models I’m not familiar with. Everything I know about was fiberglass with wires buried inside them. Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ

Won't this violate copyright laws? Jack, W8TEE

Interesting indeed! As a humble librarian I can only chip in with what I know and can. If someone wants a copy of the " HF radio systems & circuits" (1998) book as a pdf, send an email to

Actually the antennas were aluminum, 3 or 4 sections. Worked great until someone painted with metallic base paint, took us awhile to figure out why wasn’t loading correctly.

Yes I think so too. Maybe next year we can walk the entire group through a build of a nice tuner… Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ VP2EHZ Owner - Operator

Yep and it probably also had a Shakespeare 222 antenna on the deck to that it was connected to. I’ve traveled the USA looking for these… I have 4 of them and they make an incredible 40M

The ship I was on had these. Worked ok, only problem we had was the inductor would come off of its stops, otherwise was good. Tuned a 32' whip. John Myers II WB9EWM

Well that is the caveat isn’t it? You can make one measurement (plot the antenna on a smith chart at the frequency of interest) and then, with that information, calculate the transform needed

All this discussion has me wondering how the tuner algorithm would compensate for component and measurement tolerances, and stray reactances. The calculations to convert magnitude and phase to L and C

Extremely interesting Bill, this could be of benefit in so many applications. 73 Garry. M0MGP

You can just upload the contents of the disk to a directory in the files section here if you want… Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ VP2EHZ Owner - Operator

Great… yeah it’s a technically challenging book loaded with really good stuff. Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ VP2EHZ Owner - Operator Big Signal Ranch

I have the disk but I’m not sure what’s on it… it’s a 3.5” floppy and I’d have to dig to find a computer with that kind of drive on it… Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ

I have the disk, I will try to get loaded and send out. John Myers II, WB9EWM

Bill, I also picked one up from Amazon. I am really enjoying it. Thank you for the recommendation. -- Colin - K6JTH http://tangokeys.com

Do you or anyone have a digital copy of the disk with the software detailed in Chapter 17 ["Software for SSB"]? in either of the books ? Dick K9IVB

I have a revised edition of the book it is called HF Radio Systems and Circuits, is is supposed to be a revised 2nd edition. I purchased it in 1998 from ARRL book store. John Myers II, WB9EWM

Oh great! Now I’m responsible for inflation too! Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ VP2EHZ Owner - Operator Big Signal Ranch – K9ZC Staunton, Illinois Owner