vhf aeriel - will it work with a tv?

[Burnham_Bob]

The mail order chandlers sell splitters that will run an FM radio as well as the vhf. Anyone tried it with a tv? I have a small portable which has a built in aeriel, but needs an extetrnal one where I live. Hoisting a small self contained tv aerial up the mast is a pain. I know vhf and uhf are different, but the set's built in aerial is just an extendable one like a portable radio and I know it works in areas of good reception. Obviously if it does work, I can get a splitter at Maplins for a fractiob of the cost of the Mail order. Just wanted to kinow if anyone had tried it.

 

[Talbot]

why dont you just plug the normal vhf aerial into the tv it probably has a standard co-ax connector (mine does), then you can tell us all if it works! - unlikely unless you also add a tv signal amp into the circuit.

 

[alan]

As UHF and VHF are separated by quite a 'large' frequency, the VHF antenna will not provide as much as gain at UHF. However, as the tuning is likely done by the length of the antenna and the addition of a coil, and probably does not contain any filters or tuned amplifiers then it will possible give you some gain. Why not give it a go, I suspect it will work somewhat.
However, be careful about fitting a splitter and transmitting on the VHF, half the power (or so) will come into the TV receiver and possibly blow it. The correct way would be to use a diplexer (with sufficient Tx VHF to Rx UHF isolation) that will survive the power of the VHF and separate the signals in frequency.

Good luck,
Alan.

 

[Bergman]

In a word - no

These splitters are really not a good idea.

It seems to me a completely unecessary risk to compromise VHF performance which is an essential safety tool only to save the trouble of hanging a temporary TV aerial in the rigging.

If good TV reception is important (and I have sailed with children so I understand its value) then its worth fitting a proper TV aerial with an amplifier built into aerial base.

Don't go for an amp that is on the TV end of the coax - that just amplifies the noise.

 

[simonfraser]

is it biological ?

 

[dmayes]

You will notice that most fixed TV aerials are horizontal whereas the VHF is vertical. VHF is just over one meter in length for a quarter wave aerial while the TV ones are only about 20 cm long. The TV ones that look like a ladder are actually very positional and have to be pointed at the transmitter as they are like radio telescopes and get a stronger signal from a very defined angle. So the answer is "no", don't use a splitter, use one of the indoor amplified TV aerials from Tandy as you can position it where you want. Remember that it is also difficult keeping the aerial still in a beat to wndward, you need a really competent crewmember to keep it pointing at the station, good practise for "MOB" pointing though.

 

[pappaecho]

I paid a quid for a "caravan TV aerial" at a local boot sale. It has two enormous rubber skickers which stick to the side of the cabin, and a reasonable array of dipoles to give a good TV picture. It folds away, into a small space, and works in both UK (PAl) and France (Secam) and we have had very interesting communications from outer space, specially late on a Saturday night