Powered/Unpowered TV aerials?

[VVC-Geeza]

I wondered whether people are using unpowered or powered/amplified TV aerials?

The ones supplied with my MPEG4 DVB-T box are unpowered and i'm having some issues.When stationary the autotune finds 50+ channels but as soon as i begin to move the picture freezes or breaks up.Furthermore when i have travelled less than a mile i'm having to retune.

Is this down to the aerials?

[MARKUK]

Mick,

IMHO yes !!!

[VVC-Geeza]

Having contacted a number of different people i have found that some received powered aerials others received unpowered and one person got one of each :shrug:

Sean,

can you clarrify why we did not ALL receive powered aerials if that is what is required to make the TV perform correctly? I was told that the picture would be good for 80kph on the move with no mention of having to purchase other aerials to achieve this.As i said previously,i'm also having to retune after travelling just a short distance.When i bought my MPEG4 box i assumed the supplied aerials would be up to the job.

[HarryM1BYT]

I wondered whether people are using unpowered or powered/amplified TV aerials?

The ones supplied with my MPEG4 DVB-T box are unpowered and i'm having some issues.When stationary the autotune finds 50+ channels but as soon as i begin to move the picture freezes or breaks up.Furthermore when i have travelled less than a mile i'm having to retune.

Is this down to the aerials?

How have you determined whether they were powered (fitted with an amp) or not. The best way to be sure is to go into the DVB-T menu system and turn the power feeding the antenna amps to on and off. If you signal disappears or gets worse with it off, they are obviously have a built in amp. The pair supplied with mine were definatately the amp type - a long thin flat plastic strip type.

I do think expecting reception on the move is expecting far too much, except under perfect conditions and with a strong local signal.

[VVC-Geeza]

How have you determined whether they were powered (fitted with an amp) or not. The best way to be sure is to go into the DVB-T menu system and turn the power feeding the antenna amps to on and off. If you signal disappears or gets worse with it off, they are obviously have a built in amp. The pair supplied with mine were definatately the amp type - a long thin flat plastic strip type.

I do think expecting reception on the move is expecting far too much, except under perfect conditions and with a strong local signal.

Harry

there is no 12v supply to my aerials,unlike this one
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=310240813114&ssPageName=ADME:X:RTQ:GB:1123

[Parker]

I've used both and currently have powered but in all honesty with digital it's all down to transmitter signal strength and where you are. Directly outside my house if I do an install I will load a total of 0 channels, move the car 6 metres forward and I pick up around 25, tune outside work just 1.5 miles away I get 70+ channels. Use whilst driving will be very difficult to maintain a decent signal.

[HarryM1BYT]

Harry

there is no 12v supply to my aerials,unlike this one
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=310240813114&ssPageName=ADME:X:RTQ:GB:1123

That type is designed to require a separate 12v feed down separate wires - it has a coax for the TV signal, a red and a black for the 12v.

The DVB-T box is able to feed the 12v to amp amp via the coax, the same coax which brings the TV signal into the box.

The original Hi-line antennas are the same, with the supplies to the two amps fed from the coax.

Feeding 12v up the coax along with the signal might seem impossible, but doing so is very common. Your satellite receiver do it too, except it feeds 18v via the coax up to the LNB at the dish. The DC supply is fed onto the coax via a filter, then filtered back off at the far end where it is needed.

Could this misunderstanding be the reason why this thread has been started?

[MARKUK]

Mick,

Have a look at the menu and double check that the feed is on for the aerial from what I remember when we put it in, this was on....

[VVC-Geeza]

Mick,

Have a look at the menu and double check that the feed is on for the aerial from what I remember when we put it in, this was on....

Just checked and power is on Mark,will do what Harry suggests and try turning it off tomorrow to see if i loose the pic.Car is at the back of garage at the mo so can't do it now.

Why am i having to retune 1 mile down the road in similar terrain?

[HarryM1BYT]

Just checked and power is on Mark,will do what Harry suggests and try turning it off tomorrow to see if i loose the pic.Car is at the back of garage at the mo so can't do it now.

Why am i having to retune 1 mile down the road in similar terrain?

TV (UHF) is very much line of sight. The antenna pretty much needs to be able to 'see' the transmitter to pickup the signal from it, which is why TV antennas are mounted high. A TV in the car has to be very much a compromise.

My car parked at the front of my house I can get Yorkshire, move around the back and I get Tyneside transmitter - the surprise is that it can pick any TV up at all.

[VVC-Geeza]

Maybe my expectations are a little high,however it was certainly mentioned in the marketing that it would be possible to receive pictures on the move at up to 80kmh with the supplied aerials.
Ultimately,as you say Harry, it is a bonus that we can receive TV in our cars at all, and if necessary the short time it takes to retune is a minor issue.My gut feeling is though that if i fitted a pair of aerials like the 96db gain ones in my ebay link, reception both on the move and in different locations would vastly improve.

[HarryM1BYT]

Maybe my expectations are a little high,however it was certainly mentioned in the marketing that it would be possible to receive pictures on the move at up to 80kmh with the supplied aerials.
Ultimately,as you say Harry, it is a bonus that we can receive TV in our cars at all, and if necessary the short time it takes to retune is a minor issue.My gut feeling is though that if i fitted a pair of aerials like the 96db gain ones in my ebay link, reception both on the move and in different locations would vastly improve.

A lot of the advertised gain (db) figures really are not to be believed. A standard roof top TV Yagi antenna has a theroretical gain of maybe 20dB and those are very directional - the more directional, the higher the gain. Your car TV antenna is deliberately designed to not be too directional and also has to be relatively tiny, both major compromises where gain is concerned.

Some of the overall quoted gain will be that of the amp, but it is not a bit of use amplifying a basicaly poorly received signal from the antenna, you just end up with stronger signal which is still poor.

The plastic strip antenna with built-in amp, which is powered via its coax (as supplied by Sean with the more expensive DVB-T box) is about as good as it gets.

I really don't understand where the speed rating comes in to play in the spec of the receivers. It is a contrived specification, without any technical background. Signals don't drop out because you exceed a certain speed, they drop out because the signal is simply not adequate no matter how fast or slow you are travelling.

[tony_fry]

I beg to differ, I have a DVB-T unit that I use (Twin powered antenna's), that will work 95% of the time during my journey to work each day which is 22 miles (Crystal Palace to Dartford Bridge).

I use "A "roads and a motorway (speeds of upto 80mph) with no great lose of signal.

As it has been said before I think a lot of the problems is the reception strengths in YOUR area.

[HarryM1BYT]

As it has been said before I think a lot of the problems is the reception strengths in YOUR area.

I agree entirely. If your route is covered by an half way good signal, then it will recieve. Go along a route which is hilly where it is screened from the transmitter, then it is bound to drop out.

[VVC-Geeza]

I've tried turning the antenna power off and i do loose the picture so my aerials must be powered.I have them located on the rear screen and have now placed one in the vertical and the other horizontal orientation and this has seen an improvement.I can now travel along certain sections of road without the picture breaking up but it's certainly not consistant throughout my journey.I'm wondering if better quaility/gain aerials would improve things further?

I beg to differ, I have a DVB-T unit that I use (Twin powered antenna's), that will work 95% of the time during my journey to work each day which is 22 miles (Crystal Palace to Dartford Bridge).

I use "A "roads and a motorway (speeds of upto 80mph) with no great lose of signal.

As it has been said before I think a lot of the problems is the reception strengths in YOUR area.

Tony

are you using the standard aerials as supplied with the MPEG4 box?

Do you ever need to retune?

[HarryM1BYT]

I've tried turning the antenna power off and i do loose the picture so my aerials must be powered.I have them located on the rear screen and have now placed one in the vertical and the other horizontal orientation and this has seen an improvement.I can now travel along certain sections of road without the picture breaking up but it's certainly not consistant throughout my journey.I'm wondering if better quaility/gain aerials would improve things further?



Tony

are you using the standard aerials as supplied with the MPEG4 box?

Do you ever need to retune?

I doubt you would see any improvement by sourcing other antennas.

Whether front or rear mounted works best, will depend on whether the signal is from in front or behind the car, obviously that would mean best signal travelling there or travelling back home - unless you fitted one at the front, one at the rear.

Whether vertical or horizontal work best, will depend up whether you are tuned to a local fill in transmitter (vertical) or one serving a large area (horizontal). I would suggest horizontal, simply because if you tune to one serving a large area the same tuning will obviously last for a much greater coverage area. If you nearly always remain in one area served by a local verticallly polarised transmitter, you may find it better to use vertical polarised antennas in the car.

[baconbuttyman]

ok i have a neighbour who has a caravan, was talking to him about reception and he handed me a little gizmo (http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=300517672604) and said to try it, he got it from ebay and wow, what a difference, have just bought one from ebay my self, it's the answer to all our reception probs, you could even run your fm antennai thru it i suppose.

will try it when it arrives

[VVC-Geeza]

ok i have a neighbour who has a caravan, was talking to him about reception and he handed me a little gizmo (http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=300517672604) and said to try it, he got it from ebay and wow, what a difference, have just bought one from ebay my self, it's the answer to all our reception probs, you could even run your fm antennai thru it i suppose.

will try it when it arrives

Mick

have you tried this on the move? If so what was the picture like?

[HarryM1BYT]

ok i have a neighbour who has a caravan, was talking to him about reception and he handed me a little gizmo (http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=300517672604) and said to try it, he got it from ebay and wow, what a difference, have just bought one from ebay my self, it's the answer to all our reception probs, you could even run your fm antennai thru it i suppose.

will try it when it arrives

I too have one of those in my caravan, which is parked in my drive just yards from the car. Despite the caravans TV antenna being much higher than the car, I get very poor reception on the caravans digi-receiver. The car's TV reception is almost perfect parked close to it.

Away in the caravan we use a satellite TV receiver - now there is a thought for the car :-))

[VVC-Geeza]

I suppose the only way to know for sure if the ebay ones which claim to be 96db would improve things is to try a couple.Not cheap though at £40 each,although the feedback testimonials appear to be good.
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=310240813114&ssPageName=ADME:X:RTQ:GB:1123

I wonder what gain my supplied aerials have? :shrug:

[HarryM1BYT]

I suppose the only way to know for sure if the ebay ones which claim to be 96db would improve things is to try a couple.Not cheap though at £40 each,although the feedback testimonials appear to be good.
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=310240813114&ssPageName=ADME:X:RTQ:GB:1123

I wonder what gain my supplied aerials have? :shrug:

Someone on this forum bought one of those and fitted it behind the stop light in the rear window. This was in the early days of Sean's DD, but it might be worth asking them if they are any good before splashing out.

As already said, don't believe the dB gain figures - it is easy to just quote numbers bigger than a another sellers numbers, but how have they calculated those gain figures?

Part of that figure is the gain of the actual antenna and part the gain of the amplifier.

[baconbuttyman]

Mick

have you tried this on the move? If so what was the picture like?

No but tbh i wouldnt watch it whilst driving, but will test it when it arrives

I suppose the only way to know for sure if the ebay ones which claim to be 96db would improve things is to try a couple.Not cheap though at £40 each,although the feedback testimonials appear to be good.
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=310240813114&ssPageName=ADME:X:RTQ:GB:1123

I wonder what gain my supplied aerials have? :shrug:

Sean sells these
this is whent i have now, in my drive i cant get a signal, but when i placed the booster on i got a perfect signal

[VVC-Geeza]

Sean sells these
this is whent i have now, in my drive i cant get a signal, but when i placed the booster on i got a perfect signal

Sean does sell powered aerials Mick,as per the two supplied with my MPEG4 box but they are not the same as the one in the link.Whether the ebay ones meet their claimed gain figures or would constitute an improvement is the big question.Who's going to be the first to pod out £80 to find out? :)

I get an excellent picture with my existing aerials when stationary and can pic up 60+channels,although it is a little frustrating to have to retune just a couple of miles down the road.To be fair as my car is not a daily driver i haven't really tested the reception out of my area.It may just be that in my particular location the signal is not the strongest.I will probably see how it performs when on my travels.

Don't wan't to sound like i'm disappointed,i'm not.I think the DD is superb,and as Harry points out,it's a bonus that we can have any form of TV in our cars :bowdown:

[Mr Edd]

After spending many hours and much money on Sean's DD and DVB-T box last year and still don't get any reception. I am thinking yet again of trying to get it working.

I see that it is suggested that two aerials be used. How do you connect two aerials to the DVB-T units. I finished up buying two of these boxes and neither of them have an option to plug two aerials in.

I have the older unit that came out just before the ones with all the extra stuff that requires a separate arial for the SatNav extras. As you can probably guess I know nuffin about these things. I never got the TV box supplied by Sean to work, nor the additional one I bought off eBay. Yet they both work fine if I plug them into my house Ariel. I have also bought a raft of other aerials that still don't work in the car. Bottomless pit comes to mind.

As said £80 quid for aerials is an expensive experiment. But I already have over £120 quids worth of DVDB-T stuff collecting dust on a shelf in the garage.

My problem is if it hasn't got a keyboard and mouse I'm lost. :getmecoat:

Edd

[VVC-Geeza]

Edd

the latest MPEG4 DVB-T box supplied by Sean has twin (powered) aerial inputs.I have mine on the rear screen,one in the horizontal and one in the vertical.Gives an excellent picture when stationary in my location,i'm yet to test reception further when i travel out of the area and in different terrain.

[Mr Edd]

Yeah but that is another over £100 quids worth yet again and it probably wont work with my current DD unit. I was unfortunate enough to buy one of the last of the older units that came with the bundled DVB-T box and useless aerials that came with it. At a cost of over £500 plus additional DVB-T boxes and numerous other aerials, that is too much to throw away and start again. My car isn't worth that much more anyway. :shrug:

I am convinced it is only an aerial issue as the boxes work fine on my house aerial, so there has to be a solution somewhere.

Edd

[VVC-Geeza]

You can't pick up any channels whatsoever? In any location?

I know chrisboy has the box from Sean with the single aerial input,he told me he had to buy an aerial off ebay to get it to work sattisfactorily.Maybe worth a punt on the ebay one,you only need one.

[Mr Edd]

Nope not a single channel on either boxes. If I run a cable from my house aerial I get heaps of channels.

As mentioned above I bought all sorts of aerials off eBay and tried them in the car but never even got a glimmer of a channel. And yes I tried it a variety of areas sometimes hundreds of mile apart.

Terry at TS Autos had go for nearly a day and he couldn't get a signal either. I have asked the guys at the Nano meets but usually they are busy doing other cars so I am hoping one day I can get someone who understands these things to have a look.

But I think it still needs the correct aerials and I can't get anyone to say which is the definitive one to get. I looked at the Shark fin type but get mixed point of views about them too. So I lost interest last year but now thinking I might try again if I can get some answers.

Edd

[HarryM1BYT]

After spending many hours and much money on Sean's DD and DVB-T box last year and still don't get any reception. I am thinking yet again of trying to get it working.

I see that it is suggested that two aerials be used. How do you connect two aerials to the DVB-T units. I finished up buying two of these boxes and neither of them have an option to plug two aerials in.

I have the older unit that came out just before the ones with all the extra stuff that requires a separate arial for the SatNav extras. As you can probably guess I know nuffin about these things. I never got the TV box supplied by Sean to work, nor the additional one I bought off eBay. Yet they both work fine if I plug them into my house Ariel. I have also bought a raft of other aerials that still don't work in the car. Bottomless pit comes to mind.

As said £80 quid for aerials is an expensive experiment. But I already have over £120 quids worth of DVDB-T stuff collecting dust on a shelf in the garage.

My problem is if it hasn't got a keyboard and mouse I'm lost. :getmecoat:

Edd

Unless the unit is designed for two antennas you cannot fit two. What the unit does is choose one of the the two antennas which is providing the best signal at that particular instant. Even better would be a DVB-T unit with four antenna sockets. Really, the more choice it has for antennas on the move, the better its chances of picking up a useable signal whilst on the move.

[HarryM1BYT]

Yeah but that is another over £100 quids worth yet again and it probably wont work with my current DD unit. I was unfortunate enough to buy one of the last of the older units that came with the bundled DVB-T box and useless aerials that came with it. At a cost of over £500 plus additional DVB-T boxes and numerous other aerials, that is too much to throw away and start again. My car isn't worth that much more anyway. :shrug:

I am convinced it is only an aerial issue as the boxes work fine on my house aerial, so there has to be a solution somewhere.

Edd

No guarantee, as it all depends how good your local signal is and the terrain - but I would suggest your best solution would have been one of the slightly more expensive DVB-T units with the twin amplified antenna input.

Just to recap - I have one, it is connected to the two original Rover TV antennas in the rear window and it works pretty well. I would not expect a TV in moving car to work particularly well, but it does work reasonably. It works perfectly in my drive, whereas my caravans digital receiver pick up nothing at all - despite its antenna system being much higher than the car. The receiver works maybe slightly better on the Rover TV amplified antennas, than the pair of amplified antennas supplied with the DVB-T, but really not that much in it. Obviously the Rover antennas win on being completely invisible, unless you know they are there.

[Mr Edd]

No guarantee, as it all depends how good your local signal is and the terrain - but I would suggest your best solution would have been one of the slightly more expensive DVB-T units with the twin amplified antenna input.




Unless the unit is designed for two antennas you cannot fit two.


So what you are saying is, I was sold a pup. I knew nothing about these things then and bought it in the good faith that I would have a working unit. I understand that the signal strength is a factor but as you travel around it should pick pick up a signal in some place or other, it hasn't and I have tried believe me.

Edd

[VVC-Geeza]

Harry

i followed your suggestion and placed my aerials on the rear screen behind the darkened glass at the edge,they are completely invisible from the outside which i find much more acceptable ;) I can pick up 60+ TV channels and 30+ radio stations,and as mentioned reception improved when i placed one of them in the vertical.Next up is to locate the remote sensor in the courtesy light fitting behind the black plastic to hide that too.

http://i155.photobucket.com/albums/s303/mick_064/Aerials001.jpg

http://i155.photobucket.com/albums/s303/mick_064/Aerials019.jpg

[baconbuttyman]

Are you running the two antenna's from a splitter

[VVC-Geeza]

Are you running the two antenna's from a splitter

No,the MPEG4 box has twin aerial imputs.

[HarryM1BYT]

QUOTE=Mr Edd

So what you are saying is, I was sold a pup.

No, absolutely not. You bought what was available at the time and a similar system to what many others are selling. As with everything, you commit to buy what is available when you buy it - always there will be something better along next week.

I knew nothing about these things then and bought it in the good faith that I would have a working unit. I understand that the signal strength is a factor but as you travel around it should pick pick up a signal in some place or other, it hasn't and I have tried believe me.

I have really no idea why you NEVER pick any signals up. Any local high spot should see it picking up a signal. It sounds as if something is very wrong. I do wish you lived nearer so I could take a look at it.

[HarryM1BYT]

Are you running the two antenna's from a splitter

No, you cannot use a 'splitter' or 'combiner'.

There were two DVB-T units for sale, the cheaper unit worked with one single antenna. The more expensive/ more capable unit will work with two antennas, simply choosing which of the two picks up the better signal and making use of it - as did/does the original Hi-line TV receiver.

Another difference (I think) was that the cheaper receiver did not provide a supply via the coax for an amplified antenna - any amp had to have a sepearately wired 12v feed to it.

The more expensive unit can be configured to turn the supplies via the coax on or off.