RF problem
 

Hi,
Very new to the forum so apo logies if this has been discussed earlier.
Previously had RF connected to Video and then a boosted signal fed to 4 other TV's. STB went backside up so had a Samsung installed yesterday. When I select what was the video channel to watch cable progs have a very poor picture. Have tested cables and swapped boosters (which don't seem to be boosting) but still get awful picture. Ideas please?


:dunce:

Re: RF problem
 

hi and :welcome: to the site , is this not just a simple case of a slight retune needed ???????? , or am i being simple :disturbd: :D :D , enjoy your stay :tu:

Re: RF problem
 

Many thanks for a very warm welcome.

I have tried tuning the video but cannot alter poor picture. Do you mean that I should tune RF on the STB?

Re: RF problem
 

can you do a drawing of how your kit is connected :)

Re: RF problem
 

You could try changing the RF channel of the STB. Have a look at http://www.cableforum.co.uk/kb/81/ho...nel-on-the-stb

Re: RF problem
 

Thank you both for responding.

I haven't been able to figure out how to draw and attach drawing so I will try and explain.
NTL cable in to STB;STB SCART connection to 3 way SCART splitter and Video which has SCART to 3way SCART switcher. DVD connected to SCART switcher. SCART switcher connected to TV.
RF from STB to video, RF out is split to TV and via signal booster to wall socket and hence to 4 TV's.

Hope that this makes sense.

Re: RF problem
 

Since my Pace box went to STB heaven I have had a Samsung box. I have what sounds like a similar wiring set up (toi Vernon) to get the RF signal round the house. BBC1 and 2 and the STB selection have all now disappeared into a snow storm where as they were watchable before.

It seems to me that the signal level (SNR?) from the Samsung is not as good as the Pace box. Can that be altered or do I just need to put in a big RF amplifier as near as possible to the output of the STB?

Re: RF problem
 

You probably want something like this:

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Have you tried re-tuning the televisions? There's a good chance that the Samsung is set up to transmit on a different channel than the Pace.

Re: RF problem
 

why do you need the RF from the STB to the Video? Surely using the scart is better?

Re: RF problem
 

1) So that the video can record a terrestrial channel at the same time as you are watching a cable channel on the main TV.

2) So the RF outputs of both the STB and the VCR are available to the remote televisions.

Re: RF problem
 

.. and also so that I can change channels on the TV in the bedroom without having to get out of bed, walk downstairs change the channel on the STB

except I can't see anything at the moment on the bedroom TV !!!!!

Re: RF problem
 

Since you have a Samsung box then you can use any old videosender to send back the remote control signals.

If you had an older Pace model then you'd need a DigiEye DG100DE:
http://www.digisender.net/dg100de.htm

Re: RF problem
 

Ah! You should make note of the fact that the Samsung STB does not have an analogue pass-thru (which an older Pace may have had) and as such, you will either need an aerial or to split the NTL cable (see diagram above).

Re: RF problem
 

huh? you need an aerial to be able to do this. Connecting the aerial to the STB and then to the video serves no purpose. It might as well go from the aerial to the video.

Re: RF problem
 

So how, then, is the signal from the STB going to get to the remote TVs - thought transference?

Re: RF problem
 

Unfortunatly the Samsung STB comes without an internal Analogue bypass, one is however available and should be fitted if required on a STB swapout.

It is a silver block approx. 5cm square that fits onto the back of the STB where the cable coming from the wall is connected. Unfortunatly the RF gain is quite low from the STB and will be reduced further by installing the bypass.

If the bypasses wern't installed when the boxes were swapped out in these two cases I would suggest a polite phone call to faults requesting one.

hth

Re: RF problem
 

:confused: why does an aerial need to go into the STB, out of the STB, into the VCR, out of the VCR, into a splitter and then to the TV. Surely you can put the aerial and RF output of the STB direct into the VCR and miss out the loss of the aerial goping in and out of the STB.

I was just suggesting that all the splitters and amps and losses in and out of devices could be whats affecting it

Re: RF problem
 

The STB adds its RF signal to those received by the aerial such that the VCR and eveything beyond that can receive the cable channel as well as the standard terrestrial channels.

Technically, the aerial does not go into the STB but is mixed with the RF signal coming out of the STB by a powered block on the back. So this should not be an issue.

Re: RF problem
 

How exactly do you want to connect them gary?

1) aerial --> VCR --> amp --> TVs
- remote TVs cannot see STB output

2) aerial --> VCR and separately STB --> amp --> TVs
- remote TVs cannot see terrestrial channels, main TV cannot view terrestial channels while VCR recording cable channel

3) aerial --> STB --> amp --> TVs
- VCR cannot record terrestrial channel while main TV is watching a cable channel, remote TVs cannot see the VCR.

4) aerial --> STB and separately VCR --> amp --> TVs
- very little would work!

So long as the signal is above a minimum threshold the picture quality will be defined mainly by the SNR at the receiver. Yes, this will deteriorate slightly each time it goes through a box but the effect should be minimal. The best way to improve this is to fit a better aerial. Okay, I will admit you would be slightly better off if you ran the aerial through the VCR first and then through the STB but then I couldn't get the analogue bypass option into the same diagram!

Re: RF problem
 

But I don't have an external aerial as input to the STB. Both the Pace and Samsung boxes generate an RF output from the NTL cable input.

I do have the small box on the back of my Samsung STB

Re: RF problem
 

The only RF output the Samsung STB generates is the current digital channel.

The same goes for Pace STBs but older ones would also pass-through the analogue RF channels on the NTL cable. To do the same with a Samsung STB you need an external pass-thru box.

What is plugged into the "small box" on the back of your Samsung STB? It may be a pass-thru or might it be a TV aerial loop-thru like I have on my Pace box?

Re: RF problem
 

There seems to be a bit of confusion here on terminology.

ntl basically provide two devices both of which sit on the back of the STB;

1 An RF/aerial Combiner. Two cables plug into this, your old roof aerial and the cable that ntl installed to carry your ntl services. You then tune your TV and video into the BBC/ITV channels (also called off airs) coming straight from the local BBC transmitter.

2 A bypass, also commonly called an analogue or RF bypass. Only one cable plugs into this, the one that ntl installed. You now tune your TV and video into the off airs that ntl send down the network.

There are several different versions of both of these devices available but as a rough guide if there is a socket on it the same as the one on the back of your TV then its a combiner and you need to put an aerial input into it. If for some reason you don't have an aerial available there are ways around it, do a search of this site or get ntl to come round and do the job properly rather than bodgeing it yourself.

If the only connectors on the device have a screw thread then you've got a bypass.

The other thing that confuses many folks is the Scart options. These are generally either a thick cable with roughly rectangular connectors on it or a flat cable with the same roughly rectangular connectors.

These provide the TV and video with only one channel at a time, the one the STB is tuned to. If you only have a scart lead connected to your TV and Video your only going to be able to watch the same channel as the one your recording.

If you now add an RF (usually thin) cable from the aerial out on the STB (providing you have a bypass or combiner) you have a few more options. You can tune your TV and video to the off airs and watch for instance BBC1 on position 1 on your TV while recording ITV on Position 3 on the Video, or watch Ch4 on position 4 on the TV while recording Sky One from the cable on either position 6 or the Scart/AV position on the Video.

My apologies if anyone feels I'm insulting their intelligence here but I though it might explain things for some folks.

Your probably suffering from the low gain of the Samsungs then mate, if you've not already got an amp then give one a try, I think B&Q do a cheap one that you could probably return if it doesn't help ;)


Bob, afaik theres only a bypass available for the Samsungs.

Re: RF problem
 

Just to add to the confusion....

There have never been bypasses available in Bromley areas, only Langley.

There are internal bypasses on all Pace 4001s, except the last revision (I think it's the NC -- the one without audio outs, anyway). There are external bypass units available for the 4010 and the Samsung.

Re: RF problem
 

SO NTl should know about these bypass units?

Whenever I phone up they say its not possible to video digi Cable tv and watch coax (terrestrial TV)

I have my old TV aerial (coax )plugged in to the TV, Crap picture

However, my neighbour has her ntl cable split before the STB then one coax to the stb and one to the TV/Video

Can I ask NTl to supply and install this?

Re: RF problem
 

You can, but they may charge you a call-out fee.

Re: RF problem
 

It depends where you are in the country. What channel is BBC1 on?

They'll almost certainly charge a call-out fee, don't know what this is though.

Re: RF problem
 

I am in Surrey, KT19 postcode, what do you mean what is BBC1 tuned to (BBC London)

Re: RF problem
 

Sorry, BBC1 is on Both Digi channel 1 and aslo channel 1 on TV (coax loft aeriel)

Re: RF problem
 

BBC1 on channel 1 means that you're in what's called a Bromley area, and as such, NTL won't fit a bypass unit for you.

There are ways to do it yourself, but they can cause problems, and breach the T&Cs of the service if they send "dirty" signals back up the cable.

Re: RF problem
 

My neighbour has a cable splitter (installed by NTL guy) she gets perfect terrestrial chanels direct to her TV through NTl cable.