I am not a mechanical engineer so I take a DIY-style approach to aerial construction.
Most components that I use are from electronics suppliers, DIY shops and local hardware outlets.
Most of my cables and coaxial connectors come from Moonraker.
1. 100' (30m) long wire at about 5' above ground (80m and 40m)
2. Indoor inverted vee dipole in the attic (20m to 10m)
3. Three element beam (2m band)
4. Four element beam (2m band)
5. Seven element beam (70cm band)
6. Short five element beam (2m band)
1. The longwire ran up one side of my garden (north east to south west) next to a wooden fence. Its height above ground was on average 5' (under 2m). At the house end of the wire there was a metal tube which I knocked into the ground to form some kind of earth. This was where I connected my ATU and ran co-ax through the conservatory window to my radio. I have successfully contacted stations in Wales, England, Scotland and Holland with this aerial on the 80m and 40m bands. This aerial was a real compromise but was invisible to neighbours! This aerial is really invisible now because I have taken it down so it isn't damaged during hedge cutting. Now dismantled.
2. My inverted vee was my first amateur antenna and is the most used. It is situated in my attic and by using my ATU I can make contacts on any band between 40m and 10m. Performance is best on 17m and 15m and it really becomes poor at the lower end of 20m and on bands above 12m. Good contacts have been made at these extremes into Europe and during sporadic E openings on 10m. DX has been worked with just 5 or 10W PEP on 15m when conditions have been favourable. Now dismantled.
3. For some 2m FM work I made a 3 element 2m band beam. I designed it using MMANA software and it has a theoretical front to back ratio of over 18dB. It is a real Heath Robinson affair at the moment - I used the ribs from an old golf umbrella, which were 2mm diameter for the elements and screwed these onto a piece of 1/2" timber from B&Q. I later replaced the director and reflector ribs with 2mm fence wire which I fixed onto the boom using hot-melt glue. The whole thing is fed using not-so-ideal RG58 coax with a BNC which is then adapted to an SMA connection for use with my VX5-R. This highly lossy method of feeding still gives me strong West Midlands stations at S9+ and also GB3DX (S4), GB3HH (S2), GB3VT (S3), GB3IN (S9) and of course GB3CF (S9).
The directivity of this aerial is quite impressive. At the moment I use it in my shack, balanced on top of a wardrobe. I have made contacts with a maximum of 5W PEP into North Nottinghamshire, West Midlands, Shropshire and under lift conditions Essex and I have even opened a French repeater! One summer I joined some clothes props together to form a 19' mast and put my Yagi on top. I could actually hear quite a few stations from the north including Barnsley and NW Manchester. Sadly this "mast" was too difficult to put up due to it tangling up in a couple of trees and a washing line, so now I am experimenting with an 8m long telescopic roach pole.
4. I wanted to increase signal strength on 2m so I designed (using MMANA) a four element beam antenna with a greater F/B ratio than the 3-element aerial shown above. Initial tests showed that the directivity of the aerial was better than the 3-element but overall received signal strength was only marginally better than before.
This aerial was much larger than the 3-element which made it very
difficult to handle especially indoors. The small improvement in
performance over the 3-element beam didn't justify keeping the
4-element, so within hours of constructing the 4-element aerial, I
dismantled it and then constructed a 70cm aerial (details below).
This 4-element aerial was constructed using 1/2" timber as the boom and the elements were made out of 2mm diameter steel fence wire. I didn't have any more umbrella ribs but I had acquired some of this wire which was much easier to cut than the umbrella. The elements were attached to the timber using hot-melt glue.
I have tried this aerial mounted on a
camera tripod indoors mainly on SSB in the RSGB UK Activity Contests
and have worked as far as northern France without any difficulty using
Since moving to a new QTH this aerial is now mounted in the loft on a Daiwa rotator fed with Moonraker's Formula Zero coax. Within the first two months of trying this new set-up I have worked into the Isle fo Man, Wales, northern England and have heard a station in Scotland - all on SSB.