This is my 5 band vertical antenna in my summer cottage. It is for 14MHz, 18MHz, 21MHz, 24MHz and 28MHz.
Each element is electrically 1/4 wave long and they can be easily adjusted with the telescopic construction. The tuning clamps are at 2 meter height.
Click the pictures to enlarge.
GP5 antenna in working position in summer cottage. The tube supports are made of PC plastic, spacing 20cm. |
Guy ropes binding in progress. Yrjo OH3YP is helping. |
GP5 is very light. See the clamps for each band individulal tuning at 2 meter height. Tube tops are capped with plastic plugs. |
The antenna base is laser cut stainless steel. Stainless steel nut rivets for radial wires. The base insulator is machined of POM plastic. Water tight type N bulkhead connector. |
Common mode balun in the feeding point. Four radials for 20m and two for each higher bands. |
Tuning in progess with miniVNA Pro. Tuning was very easy because there is very little mutual effect. |
SWR graph
Aluminum tubes
Material natural aluminium (not anodized)
Upper tube inside lower tube. Lower tubes cross split abt 7cm for clamping
14MHz (center tube)
Lower tube 32x1.5mm L=2.1m, upper tube 28x1.5mm L=3.3m
Higher 4 bands
Lower tubes 12x1.5mm L=2.2m, folded 45 degrees at 28cm
Upper tubes 8x1mm
18MHz L=2.1m
21MHz L=1.6m
24MHz L=1.0m
28MHz L=0.7m
Antenna base drawings
Base drawing 1
Base drawing 2
Base insulator
Update 2017-01-29 OH7SV
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