Introduction: Gray-Hoverman Foil Antenna.
Taking the existing format (sort of) and converted it to a complete foil antenna. This project is based on units made on this site and elsewhere. We will add 2 extra reflectors in a bit different setup. This is for indoor use only. This was just a prototype so it is anything but perfect...Update: This antenna is extremely iite weight. If it had had some kind of yagi, it probably would have worked a bit better, only missed one station but found others.Existing stations were much sharper. Wish my camera was better though.
The Gray-Hoverman Antenna For UHF Television ReceptionMarch 11, 2008
Updated March 22, 2008 (corrected SBGH performance plots)
This project is dedicated to Doyt R. Hoverman (b.1913), the man who created and did the early work on the Hoverman antenna at a time when antenna modeling programs did not exist. His work would have been entirely created and improved by field testing, trial and error, and with a great amount of calculation without the benefit of electronic devices. Without his efforts, our work would not have been. Doyt Hoverman passed away in December, 1989 at Van Wert, Ohio, USA.
First, A Bit About The Original Hoverman AntennaDoyt R. Hoverman's original design for a television antenna was granted US patents #2918672 on 22 Dec 1959 and #3148371 on 8 Sept 1964, which expired in 1979 and 1984 respectively. To view them, click on this link and then simply enter the patent number mentioned above to retrieve each.
In his patent applications, Hoverman describes two designs with 4 rod reflectors, full wavelength and co-linear half-wavelength reflectors, with the second design using the following specifications:
The above dimensions are for reception of UHF channels ranging from 14 to 35, as claimed in the patent. He gives design equations for shifting the range, and suggests 35-58 and 58-83, although the range 58-83 is not applicable now as UHF TV channels in North America only go to 69, and after 2009 will only go to 51.
- Driven array = 56" dual segments with 8 subsections of 7" (same as the first design)
- Reflector spacing = 3.5"
- Full Wavelength Reflectors:
- Top and bottom = 29"
- The two middle = 24"
- Half Wavelength Co-Linear Reflectors
- Top and bottom = 14"
- The two middle = 10"
The original Hoverman antenna design did not have a reflector and used a driven array of 56" segments with eight zig-zag 7" sub-elements. The original patent # 2918672 claimed UHF and VHF reception. The modeling results did not find any positive net gain for VHF Low channels 2-6 nor for VHF High channels 7-0DH.
More info at:
Step 1: What's Needed.
2 - rolls of foil.
1 - mounting (a thick one) poster board
1 - regular poster board
lots of tape.
1 - transformer.
Step 2: Making the Foil Lengths.
You will need a total of twelve sections of the following lengths/
2 - 54 inch lengths for the directors
4 - 11 inch lengths for the center reflectors
8 - 12 inch lengths for the top and bottom reflectors.
Take each section length-ways and then repeat folding in half till each section gets down to at most 1/4 inch wide.
Step 3: Preparing the Directors.
This is the tricky part. The two directors should look like the picture when done.
Measure 5.5 inches.
Bend the foil to about 135 degrees
measure seven inches/
Bend the foli back at 90 degrees.
Keep going in a zig zag till all three points are done.
Bend the las of the foil back parallel to the original section..
Measure 5.5 inches.
Cut off any excess.
Repeat the process for the second director.
Note: The reflectors should not need modification.
Step 4: Preparation of the Antenna Frame.
The four short reflectors go in the middle and the rest go to the outer ends,. Measured from the bottom to 7.5 inches and put the second set of 12 inch reflectors. then measured 5 more inches for a total of 12.5 inches to install the 11 inch reflectors. The reflectors except for the ones on the edge are centered on the lines.
Step 5: Putting It All Together.
Now we just have to make the standoffs for the directors. You will need probably eight to fourteen of them depending on the size you make them. The only critical measurement is the height of four inches. Once you have all the stand offs attached to the board, tape on the directors. Add the transformer and you should be done. If I had made more time for it, it would have looked a lot better. Considering the price five dollars in materials, one can not complain.