Hi Mike,
You should enjoy much improved DX performance with an inverted-L and ground
radials than you're having with your off center fed dipole (OFCD). I recommend
you simply use an inverted L rather than a T vertical. The T vertical offers
little advantage if the T top isn't nearly symmetrical.
An inverted L will work just fine, many of us use them with excellent success.
Try to make the vertical wire as tall as possible.
Good luck!
73
Frank
W3LPL
---- Original message ----
>Date: Fri, 4 Jan 2013 06:56:07 -0700
>From: Mike Armstrong <armstrmj@aol.com>
>Subject: Topband: A little assistance needed with an attempt at a T antenna
>To: "topband@contesting.com" <topband@contesting.com>
>
>
>Hey guys and gals,
>I have a question: I have an OCFD that is about 130 feet long, end to end. It
>is Off Center Fed at a current node for 15 meters, which is the band it was
>designed for. Ends up that it tunes easy on just about any band, albeit with
>open wire feeders and a tuner. It works very well for 10, 15, 17 and 20,
>since the major lobes are directed where I want them. Although anecdotal,
>what I can say is that I rarely have to make a second call to any station I
>want to work on those bands..... which was a very real surprise considering
>its simplicity. it is 40 feet high, which is not great, but it is as good as
>I can do. I have actually tuned it to 160 during a contest last year and
>ended up working (and thank you guys, CONFIRMING) a total of 9
>countries....... Japan, Australia and Chile included..... Which REALLY blew my
>mind. But I digress...... Suffice it to say that for the higher bands, I am
>very happy with it.
>
>I want to try to use it as a T antenna and lay out some radials. I do have a
>limited space situation, from a 160 point of view, with the typical postage
>stamp lot. I got the OCFD as long as it is by placing a good portion of the
>antenna in my Mother-in-Law's property and terminating the far end in one of
>her palm trees. I needed to say that because some folks might wonder how I
>put a long antenna on a postage stamp lot..... I didn't..... It is 2 postage
>stamps side by side. However I can't go crazy and lay antennas everywhere on
>her land. So...... After all the preliminaries, I want to try the T, but it
>definitely struck me that the antenna, being OCFD as much as it is, is
>definitely NOT balanced side to side. Would this have a negative impact on a
>T? Would it be better to call it an inverted L and just forget the short
>side, including that side of the transmission line? I am thinking that the
>latter is probably the way to go, but if a T would work in such a strange!
!
>c onfiguration, I would prefer to use the extra wire rather than having it sit
>idle.... LOL.
>
>Anyway, thanks for taking the time to read this tome..... Any response would
>be welcome, especially if anyone has actually done something similar with an
>OCFD that is so "unbalanced." Ay anecdotal data concerning performance is
>welcome, as well...... If you are still using it, because it is a decent
>performer on 160, that matters because you guys are so willing to alter
>antennas if they aren't doing EXACTLY what you want them to...... He he he.
>
>Mike AB7ZU
>
>Kuhi no ka lima, hele no ka maka
>_______________________________________________
>Stew Perry Topband Distance Challenge coming on December 29th.
_______________________________________________
Stew Perry Topband Distance Challenge coming on December 29th.
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