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Thought i might put all the antenna's i have tried in one post. I know some are attached to other threads, but i thought i would put them all in one place.
The first is the Hentenna - A Japanese invention that works extremely well on the UHF CB band, aswell as the 6m , 2m and 70 cm Amateur bands. The picture shows measurements for 120 Mhz Airband, and it works fine for receive in that band aswell
The second is the J-Pole, made from copper tubing, this design is sturdier than any fibreglass vertical i have had, and can be made from almost anything conductive, such as copper tube, wire, aluminium, even plastic conduit with multi strand wire inside.
The third is the Slim Jim, another all copper tube antenna that can be made with wire or alloy tube just aswell. You can even convert a J-Pole into a Slim Jim with a few bits and pieces.....another GREAT UHF base antenna.
The fourth is the Quagi, an 18 element beam antenna that uses hardwood for the boom and push through elements. The beauty of this is that it needs no matching, if the elements and spacing are within 1-2mm of those shown, it can be directly fed from an SO-239 connector and 50 Ohm co-ax straight to your radio.
It can also be cut down to 8 elements without losing a lot of gain, but considerably shortening its boom length.
The fifth is a queer one that works great as a scanner antenna for anything from 110 Mhz to Microwave, any lower it gets slightly BIG. Works great for Air scanning and is excellent on the UHF CB band. The VE3SQB Cir Pol OMNI.
The sixth one is a Vertical, the 9 Db Co-Linear Co-ax antenna. This is self explanatory.
The seventh one is another WEIRD one, if not for the design, the feedpoint is peculiar. It works quite well on UHF both right way up, and upside down...it's very easy to mess the lengths up and make it poorly, so it does require some close care when building. The lengths are 1/4 inch tolerant, but the feedpoint gap is not. I got away with 1/2 inch vertical and 1/2 inch horizontal seperations, but the second time i built one, the gaps needed adjustment to less. The first one was copper tube, the second was steel "bundy" tubing, and the velocity factor was unknown. The composition of the metal made the antenna slightly shorter all round.
But do try " The SKYHOPPER " .
The eighth one is another odd design , and requires some careful assembly. For 477 Mhz, the gap in the elements is only 3.5mm and the array is 2 pieces. Holding them together at the right separation and keeping them there is a bit of a fiddle, but once it's up and running, its a great antenna that covers an incredible range of frequencies at under 2:1 SWR. It can be made as a 4 element too, and this can cover approximately 30 - 50 Mhz from its centre frequency without going above 2:1 SWR. Gain is around 7.6 Db on 3mm elements at 477 Mhz.
The ninth is the simple discone, a stalwart and trusty beast. A cosmetically challenged old girl, not a fancy pants wired up , spunglass shafted nicety, no WHIZZBANGS or FUPLEDRUPLES or such...but an honest ol' girl that can hear your granny chatting about her apple pie recipe last century...or the ISS and NASA aswell....20-2096 Mhz and above RECEIVE on one antenna, and transmit on almost any band with correct sizing.
The tenth is perhaps the SIMPLEST antenna in the world to make for UHF but can be made for anything down to 10 metres. The MONOPOLE, also known as the Groundplane , the Half Dipole and the Image Antenna. Its simple to make, and requires no real knowledge of antenna design. I have made HUNDRED'S of these for everything from 10 metres to 3 centimetres. They work great in HIGH coverage area's and are OK for regional or country area's on VHF/UHF if there is a repeater in the immediate area. I have made several contacts to the USA and Europe on an 11 metre version with under 25 watt output power, and have DX-ed New Zealand on 27 Mhz AM many times on the same antenna with 3- 5 watt output power. Simple to make and mount, its a favourite of mine and many HAMS swear by them too.
477 Mhz UHF CB Antenna's
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Azoic
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477 Mhz UHF CB Antenna's
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Mrmagic
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Re: 477 Mhz UHF CB Antenna's
Hi everyone ive just moved back to the gold coast live in the southport area my name is shane I would like to put a 9 element beam up my place say will.b sitting about 15 off the ground fo my uhf I have a boom and all the aluminium to build it I used to have all specs on this but have lost them if anyone is able to help with the size of rwflector element and all the other lenghths of elements and spaces between them it would be much a
ppreciated
ppreciated