YES Jeff The feed line is part of the ant and does a lot of radiating. The Windom is not a good ant for your residential area. It generally works against an earth ground but it might be possible to feed it with a balanced and tuned 1/4 or 1/2 wave balance line and just attach it to one side leaving the other side open. Don, K4KYV has some experience with a end fed unbalanced Zepp and may be able to enlighten you more on the characteristics of such as this. Of course the End fed Zepp is something of a all band antenna in it's self.
John, WA5BXO -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Geoff/W5OMR Sent: Monday, December 27, 2004 11:29 AM To: Discussion of AM Radio Subject: Re: [AMRadio] Windom Antenna > In QST magazine for September 1929 the original Windom Antenna article > starts on page 19. It clearly shows that it is exactly resonant on all of > it's design bands, so long as there is an harmonic relationship. 80-40-20-10 > etc. There are diagrams included which show how this is determined with an > RF ammeter and a rolling trolley after which very precise and repeatable > formulas were derived. Of course this is the single wire fed version. The > later 300 Ohm job is merely wishful thinking.The length in feet is always > 468, divided by desired frequency in Kc. For the lowest desired band. The > tap is always feet times 25 divided by 180. I might add that antennas put up > as temporary during this nasty winter weather last 20 to 30 times longer > than summer installed permanent antennas. happy antenna experimenting. 73, > K4XM, Mike. So, in order for this to work, you have to decide what frequency you're going to operate on, on the HIGHEST frequency the antenna will cover. ie: 29MC /2 = 14.5, 7.25, 3.625, 18.125Mc. that being the case, then L = 468/f(L) L = 468/18.125 L = 258.20689655172413793103448275862 Now, you said that the 'tap is always feet times 25 divided by 180' T = 258.207ft * 25 / 180 T = 6455.17 / 180 T = 35.862068965517241379310344827586 Single wire feeding it? Fed against Ground? Doesn't the single feed-line then become part of the radiating antenna? Even if someone were to take, say the output of a link and feed it directly to the open wire feed-line, the open wire line would have to go all the way to the feed point of the antenna, wouldn't it? I'm sorry if I'm seeming a little dense, but I can't get unwrapped from the 'single wire fed version' of this antenna. Open wire output from the link has *2* wires. I can see attaching them to some open wire line, and feeding this Wyndom antenna at 1.8125, and having the antenna resonant on 3.6250, 7.250, 14.5 (oops - can't operate there) and 29Mc, but I simply fail to understand how one wire is going to feed an antenna thas has two posts to connect to. Certainly has me thinking, though. Now, if I could just come up with land that had 300' (for guy supports on both sides) I'll have to work CW on 3.6250, forget about 20m and enjoy a multi-wavelength antenna on 10m (when the band is open). Pardon the sarcasm ;-) Seriously, here. Surely, there must be something I'm missing, to be able to use this antenna on all bands, with acceptable VSWR. 'Splain it to me, please. Happy New Year 73 = Best Regards, -Geoff/W5OMR ______________________________________________________________ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:[email protected]
