I have 2 Premax products still in use.  A 5 section vertical with a home brew matcher at the bottom that covers 160-30 meters utilizing a remote control 50 turn Miniductor tapped in 10 places, 4 taps for 160 alone.  30 meters required an inline capacitor as the ant was too long and the inductor  too big.  I have it set to about  34 feet and guyed at the bottom section but not in the middle.  The poison ivy does not enhance radiation. The other is a Premax antenna custom mounted to a cast aluminum box that was originally used for receiving WWV on 5, 10, or 15 MC optimizing with a small L tuner coil and variable capacitor in the box, but now I just use it as a dedicated SWL antenna.  It is 3 sections and set to 20 feet. The ad is from the 1940 Handbook, Premax made several antennas.

Charlie in NC