Improving TV and radio reception (1 Viewer)

R

Robert Clark

Deleted User
Hi Guys

Our MH has a 'stick' roof aerial which feeds the radio and TV.
It had a small steel plate on its base, which rusted and was replaced with an aluminium one.
The radio reception is rubbish and I'm wondering if it would help if I fitted a piece of stainless steel sheet over the top of the aluminium one.

Or is there a better solution?

Would appreciate any suggestions

Thanks
 
Oct 30, 2010
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Our reception seems pretty good on both FM radio and DTV.
I still have the steel plate, which also went rusty, but have painted mine with white Hammerite.
Not sure if a aluminium plate would make a difference but I have emailed my neighbour, who is a radio 'ham' and knows all about such things.
Can't nip next door to ask him as we are 1000 miles apart at the moment. :xgrin:

Richard.
 
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R

Robert Clark

Deleted User
Thanks Richard would appreciate the opinion of an expert

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Jan 22, 2013
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if it's conducive metal / steel/ copper/ aluminium will work fine as long as you are getting a good contact with the base of the aerial,
if it's corroded wether it's steel or aluminium then it likely that the ground plane will not work, remove aerial and clean contact surfaces,
i got great results on my fibreglass roof by using copper adhesive tape below the aerial radiating out inside the wardrobe,
the difference in reception was truly astounding,
the size of the ground plane is directly linked to the frequency you are trying to receive, lots of info on line,
 

Jaws

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Sep 26, 2008
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Ally has the same properties as steel as far as its use as a ground plane.
However, the size IS important..
If the piece of metal is small it is probably doing very little
If the are the aerial is mounted in is out of sight then the answer is simple, cheap and very light !
Get your self a roll of tin foil. Make sure it IS tin foil ( check it using a multimeter. Put the two meter probes on the sheet ( makes no odds how far apart but a few inches is fine ) and with the meter sent on resistance make sure you get a reading the same as you get if you touch the probes together

Remove the existing ground plane
Using any paste ( copydex for instance ) glue as much tin foil as you can all over the area the antenna is mounted to ( on the inside not the outside ! ).
Refit the antenna and old ground plane plate so the ground plane plate is squished up agin the tin foil

It is a trick we used to use when mounting antennas on Reliants and the like

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Oct 30, 2010
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If it helps, this is a photo of our antenna and the 'ground plane' which doesn't seem to be connected to the antenna itself.
I think that @Robert Clark has the same set up.
IMG_1568.jpg
 
Oct 30, 2010
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Mines exactly the same Richard

Can you see the wiring inside?
Can't see the wiring but I can just feel where it comes through the roof by sticking my fingers between the ceiling and wood trim above the side lockers. Not much chance of getting to anything as it is all covered by the microfibre cloth covering the ceiling.

Richard.

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Oct 30, 2010
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OK, had a reply back from my neighbour plus a further question from me and his reply. Copied below:-

Obviously something is wrong somewhere.

Assuming there is no fault in his rcvr I suggest your friend checks the feeder between rcvr and antenna and make sure it is properly connected at both ends. First of all it should be a continuous feed, not open circuit, and there should be no leakage or short circuit to earth. I cant see why a change in the composition of the ground plane plate should make any difference, provided it has been connected correctly. One very simple way to check things is to connect, using a different feeder cable, a portable or home made antenna to the tcvr and note the difference, if any. If no difference then suspect could be the rcvr. A good way of doing this would be first of all to use ones own body as an antenna. To do this just use a small screwdriver and take hold of the metal of this and then touch the ant socket of the rcvr with the screwdriver itself.


My reply:-

Thanks for that John.

I’m not sure that there is any actual connection between the antenna and the steel plate. It would appear that the plate is just glued to the roof under the antenna with the antenna itself fitted into the GRP roof covering. From what you say the antenna should be attached and earthed?? to the steel plate.

I will pass your information on.

John's second reply:-

Depends on the ant whether or not it is attached to earth. For example a tcvr on a ship and transmitting will use the surrounding sea/water as a ground plane. You cant attach a wire to water other than by immersion, which is not really necessary. Conversely my ant in my garden which is vertical for some 25ft presently has ground planes attached. This consist of about a dozen copper wires of equal length going off in all direction, some of which are under the surface of the ground. The ground planes are all attached to the braided outer sheath of the coax, all the way back to the tcvr. However, for reception only, a ground plane is not really necessary other than to improve signal reception strength or to help attenuate unwanted sig interference.

Checking an ant as I indicated in my earlier email is simple but there are even simpler and more efficient ways of doing this with an ant analyser. You may have seen me in my garden from time to time doing something that looked daft, but wasn't. That would be me using my ant analyser which tells me if all is OK and if not where the problem is. That can be critical when using a tcvr, but not when only using a rcvr.

Personally for reception only I am not convinced a ground plane is absolutely necessary. For example, some time ago when I did not have ground planes attached I had a chat with a radio ham in China and reception in each direction was suitable for that contact. On another occasion, again without ground planes, I had a 2 way contact into Australia.

So I suggest your friend doesnt get too technical but check things in a basic manner as I indicated in my earlier email.

Not sure if the above will be much help Robert but the message seems to be, don't worry too much about the ground plane but ensure the antenna connections are good.

Richard.
 

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