Total posts : 45366
I know there are alot of opinions, both pro and con, about the EH design. However, there is a ham club about 80 miles from me, north of Houston, that swears by them. Ted has several different designs, and mine is based on his “small” commercial broadcast *star* prototype. The EH uses no ground system, it’s design is supposed to pulse between the uppper and lower rings thus radiating. Tuning the EH is a tedious, pain in the arse, but after numerous calls to others that are using them on 160m and other amateur bands, I do think the design will work.
Two copper “rings” that are each 48″ tall, and the phasing coil of about 2″ tall, all wrapped on an 8″ diameter pipe still falls below the 3m limit of the rules. Not needing a ground system is another big plus, even after I buried a system for my base loaded vertical (built it about a year ago), I was not impressed with the range of about 2 miles in each direction. The EH has nearly matched that range, and it is not even tuned yet..
Without getting an analyzer though, I am at a standstill, and I do not think the el-cheapo Autek analyzer will work for this. AEA is out of my price range, I may be able to get a Palstar ZM30 or one of the Micro908 kits, but money is tight right now and I have been offered a job in Dallas. I’ll snap some pictures of my EH and post a link later today if I can, the thing is too huge for one person to handle, and my friends AEA showed we kept missing the mark too high or too low with only tiny changes in the taps, but it is functional.
Radiation efficiency is all that matters with the P15 rules, if you really want your station to have a footprint, you have to tune and tweak and tune…. Unfortunately, this requires more than just a 100mw transmitter and a legal antenna. 🙁