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Post Info TOPIC: T Antenna


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T Antenna


T Ant.JPGT Ant2.JPGT Ant3.JPGT Ant4.JPGT Ant5.JPGT Ant6.JPGT Ant7.JPGEasy to make antenna I made years ago, It works fine with Digital as well. Parts are 2x Aluminum tubing 500mm long & 16mm OD. 2x Plastic tubing 500mm long & 20mm OD. Tee piece & 2x Blanking caps. 2x S/S screws. Antenna Balun. Cable & plug. On my antenna the round black object is the Balun. The white cylindrical object is Mast Head amp.



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D.L.Bishop


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How do you get on with vert pol signals? especially if the sig strength is marginal?

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Hj Jim, Vert sig are just as good just use a 90deg elbow to tip antenna on its side forgot to show that. Other option is remove 1 end blanking cap & use a joiner on to end of pole.



-- Edited by DeBe on Tuesday 10th of May 2011 09:08:03 AM

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D.L.Bishop


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Hi Daryl, I figured you had it covered, just couldn't figure how.

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HI  ..

 

An excellent post DeBe.

 

For my part I have one of those terribly expensive but convenient & efficient Winegard antenas.

I recently fitted an Aussie model Wingman attachment to it that are designed to improve reception, particularly the digital signals.  They say that it increases UHF gain by up to 100% ie. DTV channels in the 470-860MHz range.  It does seem to work well ... but then so did the bare Winegard.

 

But despite having a fairly good technical background, even having taught CMF army signallers about radio transmission in years past, I must admit that Antenna theory is largely black art to me  .. except for the basics that is.  As a trainee 55yrs ago I must have slept through the lectures on antennas.

 

For example  ..  how can we improve the Winegard reception by attaching the wingman array  with plastic  plugs into the holes where the rubber bumpers previously were.  No metal/electrical connections what so ever.

I understand the function of the precise length arms of the array .. but how the signal is passed to the Winegard & then to the mast head amplifier gets me.

 

For vertical polarised signals, I remove one of the arms of the Winegard allowing he head to be swung into the vertical.  A bit of a pain .. but it works & only takes a few minutes with practice.

 



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See Ya ... Cupie




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Hi Cupie, Even though i spent some years installing TV antenas, its still a black art. The T type or dipole antenna has a gain of 1 or unity. Most antennas have a reflector which will be the longest bar & is the back of the antenna, next will be the pickup with wires atached different lengths diferent freq. Shorter bars are to the front of the antena some how give gain to the signal (black art bit).   Daryl



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D.L.Bishop


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Couldn't agree more! Antenna design/theory is a highly specialised field involvolving some very complicated maths, in other words "a black art".

I've been involved in a couple of VHF antenna installations and after the boffins did all the computerised modelling it was off to a test range for a week of "suck it and see" testing!

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Cupie wrote:
For example  ..  how can we improve the Winegard reception by attaching the wingman array  with plastic  plugs into the holes where the rubber bumpers previously were.  No metal/electrical connections what so ever.

 Everything is simple when you know how. For starters you will notice that the NZ-wing has 3 director elements from a yagi antenna. The directors and director do not have to be electrically connected to anything else. If they are (like in a TV antenna) they must be conected electrically in the centre.

 

Now look at the Winegard antenna. The plastic bit in the middle (radome) of the wing contains an amplifier but also it has a Yagi antenna. I believe that the yagi is etched onto a printed circuit board (so if you open that radome you probably will not notice the yagi.)

When you add the NZ-wing (or even the RV-wing) you are adding enough elements to double the gain of the combination (3 dB, 100%increase, call it what you like.)



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PeterD
Nissan Navara D23 diesel auto, Spaceland pop-top
Retired radio and electronics technician.
NSW Central Coast.

 



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Darlings there is no black art to antenna theory. Darlings it is straight forward mathematics. Jacko studied antenna theory for an interest and found it terrible exciting. Darlings you can have a party antenna design is so exciting. Small incremental alterations can make interesting changes and calculating the effects on shape of elements is orgasmic. Jacko designed a gorgeous wide Yagi 20 degree aerial for Mr Telstra's NextG and had it made. Saves having to aim the aerial accurately at the tower. For TV my darlings Jacko uses a log periodic aerial imported by Digimatch. Jacko had the aerial modified to be easily flipped from horizontal to vertical to suit the transmittter polarisation. Darlings now Jacko has VAST Jacko is inclined to use that more. Jacko bought a VAST box as soon as they were available and is in love with VAST where Aurora was only a casual fling.



-- Edited by Jacko on Wednesday 18th of May 2011 02:01:01 PM

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