tv antenna mast position

[millsy]

Have a question on the position of a tv antenna mast, most seem to mount on the back of the antenna, may be a stupid question but is there any reason not to mount the mast in the middle of the antenna? I have a tv antenna ready to mount on an extendable post on my camper and it would be more stable if I moved the u bolt mount to the middle of the antenna, I am aware that you need all the help you can get to get reception in these types of installations.
Thanks all.

[gordon_s1942]

Rear mounting is intended to partially use the mast as a back reflector and to stop it interfering with the incoming signal. particularly in areas where they use vertical polarity.
I use a 97 element yagi vertically polarised with the mast centre mounted but the bracket stands the antenna 100 mm off the mast to stop it becoming part of the receiving elements.
You will find in most cases the boom of the antenna is generally strong enough to be supported by mounting it on the rear end.

If you considering traveling any where in OZ, be aware some areas outside the metropolitan areas are still VHF, some UHF horizontal, some UHF Vertical and some mixed polarity and in odd cases, some use BOTH UHF and VHF, how bloody weird is that !!!

There is also another option if your a 'Traveler' and that is to go for the V.A.S.T fta satellite TV service which by using a dish gives you the ABC, SBS and commercial TV channels almost ANYWHERE in Australia.
The ABC and SBS are time zoned as well.

[mtv]

Thread moved to the correct section.

It depends on the design of the antenna.

Changing the mounting point where it's not part of the antenna design can change the way the antenna performs.

VHF antennas are less susceptible to having a mast in the centre that what UHF antennas are, because a mast has a greater surface area at UHF frequencies which can impact on the signal pattern.

This applies to horizontally polarised antennas.

For vertical polarisation, the antenna needs to be 'stood off' away from the mast, as it will interfere a lot more, being parallel with the elements.

[millsy]

Well there you go, im glad I asked you guys,, cause the "experts" who I bought the aerial off said just drill some more holes and mount wherever you like, I knew there would be more to it, thanks all.
While we are on a roll would it be detrimental to the performance of the antenna if I substituted the square tube the elements are attached to with a thicker wall tube, keeping the elements in the same place as the original.

[mtv]

... would it be detrimental to the performance of the antenna if I substituted the square tube the elements are attached to with a thicker wall tube, keeping the elements in the same place as the original.

Any change to the antenna design will affect its performance.

If the antenna boom isn't strong enough, buy one that is.

As Gordon mentioned, why not go satellite? The dish stays on the ground and no retuning every time you move to a different town.

Guaranteed reception (unlike terrestrial) providing you have a clear view of the sky in the direction of the satellite of course.

[millsy]

Would love to go satellite, just don't have the money at the moment

Just one more question then i can let the contributors get onto a more interesting subject, im sure.
How much effect would I expect by movement in the antenna mast, just trying to determine if a more solid pole would be beneficial.

[mtv]

The antenna in the pics is only suitable for very good to excellent signal areas.

The antenna is lightweight, so I don't think it will move around too much on that mast, so probably negligible effect.

It's one of those things you have to try out to find many of the answers... theory can only help so much.