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How do I pipe Freeview around my house


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Old 02-12-2007, 12:30
Robert Lander
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Hi, I am a new comer to digital tv and have some questions on the subject which I hope you experts can help me with.
I have a Sony Bravia TV with Freeview built in and a Panasonic DMR-EX75EB DVD recorder. Is it possible to pipe the digital signal around the house via normal RF wire? or does it have to be modulated first? I used to be able to do this with my old analogue TV and VCR, but can't understand why a digital signal (which comes down a conventional aerial and Wire, can't be piped to another tv? Sorry if I sound a bit thick.
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Old 02-12-2007, 12:39
David (2)
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Its down to this one question.....does the external device with freeview built in, also have an "RF Modulator". This is required if you want to take the output and distribute the selected channel around the building.

Many (or most) freeview decoders, and various combi's such as DVD's with inbuilt Freeview dont contain an RF Modulator. You can add on an external RF Modulator box, but this would be an extra cost.

Dave
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Old 02-12-2007, 12:53
chrisjr
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The question that needs to be answered is...

Are you expecting to be able to view every digital channel on any TV in any room of the house?

If the answer is YES then you need a digital TV in every room of the house. If you already have a system distributing the aerial signal to several rooms then you are also distributing the digital signals everywhere.

However if your only digital TV is the Sony then none of the other TVs in the house will receive digital TV. The presence or otherwise of the Sony is irrelevant to that. So you either need to swapo every other TV for a digital one or buy a set top box for every other TV.

The only thing you may be able to do is feed the RF output of the recorder round the house. Assuming that is that it has both a digital tuner and an RF modulator built in.

Obviously this means you can only watch whatever channel the recorder is currently tuned to every where else. It won't turn an analogue only TV into a digital TV for example. or allow one room to watch BBC3 and another to watch ITV4 at the same time.
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Old 02-12-2007, 12:54
Heinz
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Assume the PVR is a VCR.

As with the VCR, whatever is present on the RF out socket on the PVR can be sent around the house. It depends on what you plug it into at the 'remote' end what you get out of it though.

An analogue bedroom TV will allow you to tune in whatever analogue channels are present, a DTT STB or iDTV will allow you to watch digital channels.
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Old 02-12-2007, 13:31
MC2
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It does depend on exactly what you want to do, and the capabilities of your kit. I'm assuming that by "pipe around the house" you mean you have an (analogue) TV in, say, the kitchen, on which you want to watch the same thing as is on your Sony.

First thing is to see if your DVD recorder has a built in RF modulator, i.e. if it will send whatever you're watching to the RF output socket as an analogue "channel", just as your VCR did. As Dave says, most don't, but I'm not familiar with your model, so check the manual.

If it does, then you can wire things up as you did with your VCR and at least watch whatever the DVD player is playing/tuned into on the kitchen TV. Now check if your Sony can output whatever it's tuned into to the SCART. If so, then you can also get it to output its signal to the DVD, which'll output to your kitchen TV....

If the DVD recorder doesn't have a built in RF modulator, then you have a bunch of choices.....

If you've still got your VCR you can use that as an RF modulator. Connect it up to the rest (by SCART) and it'll output whatever it gets to the RF output socket. If the VCR is long gone, then....

Well, you can get an external RF modulator, like one of these , or an AV sender (see this thread for a recommendation for a 20 one), or you can just get an STB for the other TV, the Woolworth's 20 one is getting good reviews as a good cheap box from forum members. This last choice won't let you watch the DVD of course, but will give you "independence" on the other TV.
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Old 02-12-2007, 13:49
Robert Lander
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Many thanks for your suggestions. I'm much clearer on what I have to do. The DVD does not have it's own built in modulation (unlike my old VCR) so I think it's best if I go down the external modulator route. Thanks again.
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Old 02-12-2007, 13:56
Robert Lander
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Just one other question, If I did have digital tv's in the other rooms, How would I get the digital signal from the scart output (as with the Sony) into the aerial leads that go round the house? Is there a conversion lead or isn't it that simple.
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Old 02-12-2007, 14:09
chrisjr
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Just one other question, If I did have digital tv's in the other rooms, How would I get the digital signal from the scart output (as with the Sony) into the aerial leads that go round the house? Is there a conversion lead or isn't it that simple.
I'm not sure if you are understanding exactly what is required here.

The digital TV signals that you would use to view Freeview on a digital TV in any room of the house arrive via the aerial. It is this signal and this one only that needs to be fed to every room.

The mere fact you have a digital TV in one room is totally irrelevant. You feed the aerial cable into a multi output amplifier then run cables to each room you want a TV in. What type of TV you hang off each cable makes no difference whatsoever to the others.

Or were you under the impression that your TV fed the recorder with digital signals? The Panasonic has it's own Freeview tuner built in. It neither knows nor cares that the TV it is connected to has Freeview itself. In fact it wouldn't make any difference to it if you threw the telly out of the window! It would still be able to record programmes - you just wouldn't be able to watch them back without a TV
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Old 02-12-2007, 15:48
Robert Lander
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Sorry if I'm not being very clear. I understand that the DVD also has Freeview. But what I'm trying to clarify is:
Can the digital signals that arrive via the aerial be piped around the house, from the DVD via conventional aerial wires (using the multi-output amplifier of course) and secondly will the dvd send out recorded material around the same system.
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Old 02-12-2007, 16:32
chrisjr
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It was all this talk of SCART signals that was confusing things. It seemed to imply that you thought the TV was somehow enabling the recorder to receive Freeview (a not uncommon misconception as it happens!).

I've had a look through the online version of the manual for your DVD recorder. You have to get to almost the last page before you find the relevant data! Which unfortunately is that it does not have a built in RF modulator.

Therefore it has no means of generating a signal to output on the RF out which could be fed to other TVs around the house.

If it did then you could do this...

Aerial Downlead --> DVD RF IN
DVD RF OUT --> Distribution Amp RF IN
Dist. Amp RF OUT 1 --> Sony TV
Dist. Amp RF OUT 2 --> TV 2

and so on

But since the DVD recorder has no modulator that is not going to acheive very much.

You may as well do it like this...

Aerial Downlead --> Dist. Amp RF IN
Dist. Amp RF OUT 1 --> DVD Recorder RF IN
DVD RF OUT --> Sony TV
Dist. Amp RF OUT 2 --> TV 2
Dist. Amp RF OUT 3 --> TV 3

and so on

If you MUST have the output of the DVD recorder on the RF distribution system then your only option is a separate RF Modulator.

Which connects like so...

Aerial Downlead --> DVD RF IN
DVD RF OUT --> Modulator RF IN
DVD AV2 SCART --> Modulator SCART
Modulator RF OUT --> Distribution Amp RF IN
Dist. Amp RF OUT 1 --> Sony TV
Dist. Amp RF OUT 2 --> TV 2

The SCART connection from DVD to modulator carries the DVD output to the modulator for conversion into a UHF TV signal, (assumes DVD AV1 is connected to the Sony TV).

If you don't want the hassle of installing yet more boxes then I would recommend moving the RF Distribution amplifier as close to the aerial as possible. Best option would be a masthead unit bolted to the pole just under the aerial. Second best is an amp in the loft. Followed by the amp in an upstairs room and finally, worst case, in the downstairs living room.

Basically for optimum performance the distance between aerial and distribution amplifier should be as short as possible. Which in turn means the total length of cable between aerial and any TV is minimised. This reduces the chances of interference and signal degradation.
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Old 02-12-2007, 16:37
Robert Lander
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Thanks for that Chrisjr. I am now clear what I need to do. It looks like the external modulator is the only way.
Thanks again. Bob
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Old 02-12-2007, 16:56
chrisjr
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If you have a Maplin store nearby then you could get one of these...

http://www.maplin.co.uk/Module.aspx?...ModuleNo=33050

Not exactly a work of art but does the job

Or online...

http://cpc.farnell.com/jsp/search/pr...sp?sku=AV13328

Prettier box Uses F connectors rather than the more usual Belling Lee plugs so may be a little more difficult to connect up.

I'm sure a quick google (or should that be Google?) on UHF Modulator is bound to throw up more options.
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Old 02-12-2007, 17:34
John259
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An aerial receives all transmissions, analogue and digital, on all UHF channels. It feeds them, all of them, down the aerial coax cable. So this signal has all four or five analogue channels and all six of the digital multiplexes that carry all the Freeview channels.

A conventional analogue television has a tuner inside which selects one analogue channel and displays it.

A conventional analogue VCR has a similar tuner. The one analogue channel that it selects (or the recording that the VCR is playing) is normally conveyed to the television via a SCART cable. A SCART cable can only carry one channel, whichever channel is selected by the device sending the signal.

VCR's with RF (radio frequency) modulators convert the one selected channel so it appears to be coming from an aerial. Then a coax cable conveys it to the television. But only one channel can be conveyed, whichever one is selected on the VCR. Regardless of its original UHF channel, it is sent by the VCR and received on the television on the same UHF channel (usually 36 I think but I'm guessing).

Therefore, as far as I know, any distribution of signals via SCART cables or from the output of an RF modulator will only send one channel, whichever channel is selected on the sending device. If a person in a different room wants to watch a different channel, hard luck. However, there might be some sophisticated equipment with multiple tuners which would allow people in different rooms to watch different channels.

So, as I understand it, the only sensible approaches in a domestic setting are to either install a separate aerial per television, or to split the original full aerial feed that carries all channels and distribute that. Then each device that receives that full signal can independently select whichever channel is desired. In a digital setting that implies that each such device has a digital tuner, i.e. it is an IDTV, a Freeview STB, or a PVR. Given the current cost of STB's that isn't a problem.

Unless anyone knows different, of course...

John
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Old 02-12-2007, 19:50
SimonBlackham
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Going back to the OP... and expanding what John259 says to the history and practicalities...

Prior to digital - each device we have (normally!) had an analogue receiver bulit in. The signal comes from the aerial lead and so each device needed to have the aerial lead looped through it - finally stopping at the last in line - the TV set.

Each non-display device (typically a VCR) would re-inject a signal into the aerial for the TV to pick up - this signal was on a channel not normally used by broadcast signals (eg Radio Frequency channel 36) and the TV had to be tuned to it. Thus you would select a button channel number on the TV eg 6 which was tuned to (say) channel 36 to play back recordings from your VCR.

The SCART system was introduced and the signals from the VCR could then be sent directly to the TV - and in this case the TV was then set to AV input to display the recordings. VCRs still had the (RF) aerial output but it was no longer used.

When digital STB's were first introduced for ONdigital they also had RF aerial output - later ones dropped this. When DVD players and recorders were introduced they did not have RF output (yes there may be exceptions!) and are connected to the TVs by SCART. Some PVRs (or Digital hard disk video recorders) do have RF output.

SCART is being replaced by digital connections (HDMI) and RF signals ae being dropped - other than the original signal from the broadcaster via the aerial, cable or satellite which will need to be fed to each 'receiver' of whatever kind. In the case of DTT this means an aerial lead needs to go to each device - either daisy-chained or through a distribution amplifier to each one - or a separate aerial for each TV. Eventually each TV will have its own Digital receiver bulit in - but in the mean time - and with changing technology (eg the introduction of HD transmissions) - TVs may require an external receiver (STB, PVR etc) connected via a SCART lead and eventually an HDMI lead. If the TV does not have an appropriate receiver bulit in (eg only an analogue receiver after DSO) then the aerial lead to it is superfluous - unless you have equipment upstream of it that can provide an analogue RF signal.

Thus currently it would appear that with standard equipment the disribution of signals around a house is best achieved using aerial cable - and each TV with an aerial lead that goes through a device that can inject an RF signal can be set to receive these signals.


I have a complex system with a single aerial and a number of devices in the lounge - feeding a distribution amp which then feeds the RF signals around the house to various TVs via other STB's.

This means (for example) that the Wife can watch the output from the TopUp TV+ box in the kitchen and we can also watch it when we are in bed. The quality of the mono sound (the RF output does not re-produce the stereo Nicam that the analogue receivers can pick up) and analogue pictures are acceptable in these cases. We have STBs by each of the TVs so that this is only for watching recordings away from the main TV.

This system was originally set up a long time ago when we had two ONdigital STBs and a VCR in the lounge and the TVs were tuned so that 4 5 and 6 were these devices (set to channel 69, 60 and 36) - it involved running extra aerial cables up from the distribution amp in the lounge to the attic and down to the various upstairs TVs (the aerial to the kitchen TV is a new installation).

I have been looking at improving the distribution over the years and have discovered a few things...

1) SCART will actually work up to about 30m and high quality could be sent that way - but the cables are unwieldy and I (still!) don't fancy soldering all the connections - although not all would be needed.

2) 2.4GHz radio transmissions are no better than aerial signals - and the aerials are already laid anyway so I haven't tried it.

3) You can send video signals over shielded cat 5 cables (up to about 50') - WITH NO ELECTRONICS - because the shielded cat 5 is about the correct impedance. I have not yet tried this but there is a very long lasting American web thread all about it which I have posted many times (and will try and find again).

4) I do not know what the limitations on HDMI cables are - but the analogue part is similar to SCART and so it should be possible to send them via Shielded Cat 5 With the digital signals does anyone know the theoretical limitations ? - and the achievable practical distances.

The big advantage of the aerial (RF distribution is that a number of signals can be injected into a single cable and selected at the TV end - with anything else the route needs to be set up - or separate cables for each signal. Eg if you have two recorders then each ones output needs to be fed via cable to separate SCART inputs of the TV - the user then selects the required device by selecting the correct SCART input of the TV.

Finally there is the problem of operating equipment remotely...
In the past there were remotes available that sent a radio signal to the various devices - so the remote could be used anywhere in the house to control any device you had set up with a receiver - unfortunately they were originally very expensive and when I last looked I could not find any available. I did think of putting the STBs in the attic and controlling them by radio.
The only other way (I know) is to use the aerial lead to send signals back to devices via 'Magic Eye' or similar - and I have never got around to trying it either.
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Old 03-12-2007, 12:05
MartinImber
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Get a cheap box for each TV, saw one for 10 at the weekend
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Old 03-12-2007, 12:26
fozzi
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..... I did think of putting the STBs in the attic and controlling them by radio.
The only other way (I know) is to use the aerial lead to send signals back to devices via 'Magic Eye' or similar - and I have never got around to trying it either.
That is what I had set up when we had analogue Sky.

I had my Sky box in the attic with a video recorder. It was all piped through an aerial distribution system that sent the signal to every room in the house. Next to the boxes in the attic was a powermid master to relay all the remote control signals from around the house below. In the living room I had a three core phono cable to get from the scart on the Sky box to the scart on the TV. This enabled a stereo signal and improved video on the main TV. All the other TVs in the house were mono and had a powermid slave to send remote signals. Under the main TV I had a Videoplus handset. This system also had a frequency shifter on the scart on the Sky box to get Astra 1D which could be operated by pressing aux button on the Sky remote. It all worked well except in very bright sunshine (The IR signals just whited out I Think).

Wouldn't do it this way again. Nowadays all the kit is a lot less expensive. As mentioned a digi box for each TV is much the cheaper option.
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