Magnetic TV roof aerials
We have been trying out a Portable TV roof aerial with a magnetic mount. The reception is very good but, unfortunately, the roof of our motorhome (2010 Elddis Autoquest) is not magnetic. We can sit it on the roof unanchored, which is not ideal. The cab is metal and it will stick there but this does, potentially, restrict the signal. Wondered if we could put something on the inside of the van roof, would the magnet be strong enough to pass through? Any suggestions?
Comments
-
I would think the thickness of the roof would reduce the magnetic force to an inside plate to a point where it would be ineffective. However, the only way to find out is to try, although presumably it would mean sticking any plate to the inside of the roof. Surely the metal cab is the best place, you have the option of putting your MH face in or rear in to optimise the signal. Direction can be established using an app, or by observing the direction of the site, or local roof aerials.
0 -
Is it an Omnimax aerial? If so, you can get suction mounts instead of magnetic. Link
0 -
I very much doubt a magnet would work through the layers of material used to construct your roof. Perhaps attaching a metal plate to the outside of the roof would do the job or, alternatively, try an aerial which attaches by means of a suction cup.
0 -
Maybe you should cut your losses and save your sanity and buy one of these https://www.avtex.co.uk/antenna/sth3000 It has a sucker attachment which is pretty strong and pulls in a good system. If you have an Avtex TV it takes its power feed direct from the TV. If a none Avtex TV is used it has a separate power cable. We used one for several years on our previous motorhome.
David
0 -
Another vote for the Avtex. It has yet to let us down and just suckers to a [clean] window or your choice.
Colin
0 -
Been on the look out for a good replacement aerial. Can you tell me if this is a proper directional aerial? Also, can it be switched to vertical and horizontal polarity according to the local transmitted signal? Or is it just a simple amplified omni, David?
0 -
You do not alter the rotation for vertical or horizontal, to pick up on main transmitters or boosters. All I have done is looked at https://ukfree.tv/maps/freeview and made a note in which direction the best transmitter is. I sucker the aerial to the window but you must clean the window first or it will fall off. Plug aerial into tv and press tune. It really is as simple as that.
When teamed with an Avtex TV it sends power to a built in amp in the unit. If you have an Avtex TV then a secondary in line lead is provided for the power feed
Colin
0 -
The rod the aerial is on is flexible so you can twist it into any configuration. We mainly stuck it on the side of the van, see picture below.
David
0 -
Thanks David, I see that’s in a vertical polarity can it be switched when stuck in exactly the same position on your van to horizontal polarity? Just concerned before I buy that essentially it’s just an omni aerial! Not meaning to fuss but I bought a different make and model which promised much but performed pretty poorly where the broadcasted signal was a less than strong.
0 -
We used it with our first motorhome which didn't have a built in aerial but we did have a satellite dish but that wasn't always usable if there were trees in the way. I would say that generally the Avtex worked pretty well if you have a decent signal. Mainly I stuck it on the side of the van as illustrated by the photo but have been known to put it through a hatch onto the roof. In poorer signal areas we would find the BBC channels fine but ITV not so good as they sometimes come from different transmitters. We often had to play around with it depending on what programmes we wanted to watch. Having said that for about £35 its a reasonable bit of kit to have around.
David
1 -
We use the Apple antenna Aligner app (£2.49) this lists the available TV transmitters in order of signal strength plus shows polarisation and when you select a transmitter a compass comes up with an arrow pointing to the direction of that chosen transmitter. The Avtex aerial looks like a dipole to me so just swivel vertical and horizontal and course place it on the transmitter side of your outfit
0 -
The two basic factors for getting a good signal from a terrestrial transmitter is that it depends on how much metal one can get into the air, and how far above the surroundings it can be raised.
One then has to consider what signals are being received as well as the wanted one. This has led to all sorts of shapes of bent wire and fantastic assemblies being designed. Whatever recieving aerial one uses needs to have a good response in the polarity of the transmitted signal - in UK at least either vertical or horizontal. It also helps greatly if the aerial has an ability to receive in a particular direction as that will reduce unwanted signals and noise from other directions.
In order to avoid the user who is uninterested in this having to do much, many aerials have been produced that are "omni-directional" and/or "omni-polarity". They will work as such in an area with strong signals but they are far from ideal with weak signals. A very efficient aerial design is the Yaggi which in plan view looks like an arrowhead which one points at the desired transmitter, either lying flat or on its side. Some makers, such as Status, enclose the metal bits in a shaped plastic housing to protect them.
When the signal is strong, a straightened out wire coathanger stuck in the socket on the back of the television can be as good a some of the cheap "does everything" commercial aerials.
0 -
Trouble is we tend to go to far flung remote areas which often have ‘poor’ signal strength delivered to them. I have an expensive omni fitted on my van which is more or less useless in these situations or even in medium strength areas and have searched high and low for an alternative. Presently I carry a Log Periodic which is on a short pole, it does work slightly better but is a faff to erect and align.
Just looking at what the locals have on their roofs can be helpful mind. Large complex aerials on display usually means a challenge but these do help with determining direction and polarity. Many products promise the world but in reality don’t provide and I just thought Avtex is a good make of TV but wanted to know how it really performs in those challenging areas before parting with even more money.0 -
The reason we no longer take the Avtex with us when we go away as on our current motorhome we have a directional aerial which has been pretty good and I doubt the Avtex would perform better. When we can, we always use the site bollard if it has a connection point. I have toyed with the idea of another satellite dish but they are a lot of money and thus far the built in aerial has prove reasonably reliable.
David
1 -
The free(ish) application "Freepoint2" gives all the information one may need about direction to transmitters, distance and polarity. It has lists of Caravan Club sites and CLs - as well as the other club and commercials - so one can look at the possibilities before one arrives.
The polarity can be very important when there is more than one transmitter on a similar heading. Also note that many of the handout site maps are inaccurate in showing the direction of north so a proper map or a compass can be required.
What is not given is the path profile to the transmitter from a selected location. There could be a whopping great hill in the way so again a proper map is your friend. In these situations all is not lost since there can often be a usable reflection of the signal one wants from something like another hill that is in line of sight to the desired transmitter.
One still has to consult the Internet to find out what stations are in the mix being transmitted from any selected site though.
0
