This year will probably be a Vee beam for 40m, fed with ladder line and a tuner. Interesting factoid: Vee beams that are odd multiples of 1/4 wave seem to have impedances similar to loops, and can be fed with the standard quarter wave matching section, although that will limit their utility to a single band.
80m will probably be a dipole, 20m is uncertain. The Vee may be pressed into 20m service, and will be used if there are decent 15m or 10m openings.
Throw down a comment if you have a favorite.
Amended 6/4/08: Ok, maybe a loop on 20m. Probably diamond shaped and fed at the bottom.
My club has put up a Vee beam for 40M for the past few years with good success during field day. In ’03 or ’04 with another club, we put up a 3L quad for 40. The antenna was actually triangular but radio waves don’t seem to know the difference. The top of the antenna was 90 plus feet off the ground with the top support rope strung between two very tall trees. We worked about 450 stations on 40 CW that year.
Yeah, having a gain antenna on 40m from here near the coast is always productive. I don’t think our site this year will be conducive to a quad. A 2 element 40m inverted vee yagi would be easier. It may be we have a single loop for 20m, perpendicular to the vee beam.
The vee beam is high on the list because of the size of the field and tree location. ‘YDU started talking “rhombic”! That might be overkill. After modeling, it sure is an attractive idea. At a very low height, a rhombic has gain at higher angles that should be useful for FD.
We have a small group, so we are also thinking “simple”.
In the past two years, we got a local crane company (different one each year) to set up their crane on our FD site in town…They extended the crane to 102 feet! We built a 40 meter Bi-square. The bottom was only 8 feet off the ground and what a super performer the first year on 40! WOW! The next year we moved accross the street, set up a crane with a 120 foot height to get the same exact Bi-square off the ground by about 25 feet. We also pulled it further apart so it wasn’t quite square but more like a diamond shape on it’s side…it performed very poorly! 🙁
This year, I rented a fire lookout tower in NW Montana about 8 miles from the Canadian border…it’s a VERY remote area and incredible views all around! We’re going to put up a Tribander on a 30 foot tower, another tower to support wires and the like…hope to put up some sort of loops for both 40 and 80 meters! Be looking for N7LT “November 7 Loony Toons” “2A-MT”!
73
Lyndel, N7LT
Kalispell, MT
Hi Lyndal,
We had access to a 200′ firetower in 2007, and used it to hang an 80m sloped dipole. That really worked well, as the antenna sloped from about 120′ down to about 70′. 80m Q’s just kept rolling in all night long. The stairs have since been removed from the tower, so that was a one time set-up.
Never tried a bisquare…..Maybe one day.
I’ll be sure to keep my eyes and ears ready for “N 7 Looney Toons”. Maybe we’ll get lucky and have a good year for 15m and 10m too.
tnx es gl for FD in 2011!
73 de w4kaz