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Horizontal Antenna for the 43 Meter Band
On 43 metres I used the 40M1L by M2, a commercial dipole, although the antenna lacked the necessary height (it should be at least ¼ lambda) it worked reasonably. The design was ingenious in that the lengths of the elements could be adjusted easily by the setting of linear loading rods. It is suitable for a frequency range between 6.9 to 10 MHz. I often find out that complicated problems are rectified with hard work!
Vertical Antenna for Lower Bands
On lower bands I am using a typical Marconi vertical antenna, it works excellently! The design of the antenna is almost a century old..... in case you are wondering... yes I like proven technology! For this band the antenna has to be energized "with respect to earth" as Marconi once showed. The solution is to connect as much radials (and other conductive material!) as possible so the vertical tube will give approximately 48 Ohms at the 76 metre resonance point. With little radials the efficiency (the ratio of power radiated by the antenna to the total power fed to it and expressed as a percentage) would be approximately 8%. If you put six radials and observe that the SWR at resonance has dropped to 1.5 we can assume that the total feed point impedance has dropped to only 75 Ohms and that our efficiency has gone up to 16%. That may not sound like much compared to a full-size dipole operating at 90% efficiency or more, but don't be misled, for it still amounts to a signal gain of 3 dB! Most low-band dipoles can't be put high enough above the earth to produce much low-angle radiation for DX operation, and even an "inefficient" vertical will often out-perform a low dipole on 80 or 40 meters when the path length exceeds a few thousand miles! I copied the design of a Fritzel GPA50 and made it suitable for the 76 metre band without compromising on its characteristics. I spoke to Kurt Fritzel a few times about my modifications. Years later, when I tried to contact him again, his son said he passed away. Now a day the Fritzel Company is no longer a family business but sold to another company, never the less they still make high quality antennas
Inverted-V Antenna for Higher Bands
On higher bands I am using the most simple, proven and cheap antenna there is; the Inverted-V. All that is needed are three end insulators, a length of rope, antenna wire and in my case a fishing pole. An Inverted-V is a variation of a normal dipole that features slanting wires for easier mounting on small properties, or where you wish to mount the centre of the antenna high without having to build two high endpoints. Antenna critics agree that there is a little difference in performance between the two antennas. However you will find that for the same resonant frequency, the Inverted-V antenna needs to be about 5% shorter in its element lengths compared to a "flat-top" dipole.
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