# Signal Break Up On Ch 5 - Is Tivo Or Humax Freeview Box The Culprit?



## algordon (Apr 1, 2004)

I am being driven mad by a strange problem which seems to occur really only on Ch 5 and nowhere else. My partner and I watch a lot of the Ch 5 cop shows like "the Shield" and the 57 different varieties of "Law and Order". We almost never watch in real time so rely on Tivo. The problem seems to be worse on Friday and Saturday nights as very often "the Shield" and "Law and Order" are almost unwatchable due to constant picture break up. We also watch "CSI" but never seem to have the same problem.

I have now been through about 5, I think, Freeview boxes but don't want to have to get yet another one until I'm sure that's where the problem is - hence the question - might Tivo be the culprit, or is it more likely to be the Humax, which in fairness to it has worked very well over the last few months. What I'm describing is a fairly recent problem.

The other thing is that we have Pioneer PDP with a media box containing a digital tuner and it seems to deliver a perfectly good signal.

Help!!


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## mikerr (Jun 2, 2005)

Its your aerial reception (if the problem is only on channel 5)

Some freeview boxes are better at coping with a marginal signal than others.

You could pay £200ish for a guy to go on the roof and fit a new aerial, masthead amp etc,

but since its ok most days, you might be able to get away with a cheap aerial booster


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## ...coolstream (Dec 10, 2005)

If it were aerial-related, I'd expect you to have similar problems with other channels on the same mux as 5.

I don't know if this is related, but a couple of days ago, I was watching 5 in real time via cable (about to check cable menu) and I spotted a few sparklies and then screen went black for about a minute but sound stayed good. I played back that segment on tivo and saw the same. 

Had I been using freeview as source, I would have suspected the aerial, but since the source was cable, I would tend to lay the fault at the source. Having said this, I don't tend to watch 5 all that often so I can't really say if this problem occurs regularly.

Edit:
Just noticed that you are in Glasgow. The problem may be a glich with the Blackhill transmitter which people in the rest of the UK aren't seeing.


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## mikerr (Jun 2, 2005)

He may not watch any of the other channels on that mux, they are not up to much 

Five, Five Life, Five US, QVC, BidupTV, PricedropTV, ABC1 ...


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## Pete77 (Aug 1, 2006)

mikerr said:


> Its your aerial reception (if the problem is only on channel 5)
> 
> Some freeview boxes are better at coping with a marginal signal than others.
> 
> ...


The SDN multiplex (now owned by ITV) on which Five, Five US, Five Life etc are broadcast is often the most dodgy in a weak reception area, perhaps due to the huge number of rubbish channels they try to cram in.

As long as you have space for a dish one of these little installations for only £75 with no further commitment to subscribe from a certain Mr Murdoch would permanently solve your signal problem.

See www.dixons.co.uk/martprd/editorial/Sky Pay Once Watch Forever/?int=deal-1 Sky Pay Once

Having a problem with just one multiplex is not at all unusual. At my mum's house the other five multiplexes come in loud and clear but there is not a trace of the ITV multiplex anywhere (well there is a tiny smidgeon on my Netgem Freeview box if I take it over there but the signal still breaks up all the time). There was a signal until about 2 years ago and then it suddenly vanished. It has been suggested to me that there may be a local interference source broadcasting on this frequency that came in to existence at around this time as ITV deny having changed anything in their transmissions.


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## TCM2007 (Dec 25, 2006)

I have also experienced problems on this mux due to the signal being too strong! It's certainly a problematic mux; it used to be broadcast using a different standard, I don't know if it still is. Do you have a signal booster? If so, and it's variable gain, try altering it.


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## Pete77 (Aug 1, 2006)

TCM2007 said:


> it used to be broadcast using a different standard. I don't know if it still is


SDN is still broadcast in 64QAM. It is the BBC and National Grid Wireless (previously Crown Castle) who changed to the more robust but lower channel capacity 16QAM transmission method back in 2002.



> Do you have a signal booster? If so, and it's variable gain, try altering it.


The OP's signal readings on the box for the Muxes he can receive plus the question of how far he is from the transmitter should give him a better idea of whether he is in a weak or strong area for DTT signal. Plus the obvious matter of whether his nearest transmitter is 20 miles aways or 2 miles away.

The website www.ukfree.tv/transmitters.php provides much more accurate information than the Freeview website in this regard, including distance from the nearest surrounding transmitters.


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## Ashley (Apr 20, 2002)

This is another site that will give the local (or distant) transmitters and which aerial is required.

http://www.wolfbane.com/cgi-bin/tvd.exe?


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## algordon (Apr 1, 2004)

Thanks for the replies, folks.

I replaced my aerial about a year ago and had quite an expensive digital one fitted. The signal strength meter shows a very good signal coming in, and the aerial guy told me I definitely didn't have reception problems. (He described the signal as "booming in.")

And no, I don't have a signal booster.

From the replies, I gather tho that Tivo is not the cause of my woes?

I also noted no-one suggests replacing my Humax?


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## Pete77 (Aug 1, 2006)

algordon said:


> I replaced my aerial about a year ago and had quite an expensive digital one fitted. The signal strength meter shows a very good signal coming in, and the aerial guy told me I definitely didn't have reception problems. (He described the signal as "booming in.")


Sounds like your signal is too strong then as TCM suggested and that you need a signal attenuator. What do the UKFreeTv sites and Wolfbane sites mentioned above say regarding how far away your nearest tv transmitter is?

You need to get a coax signal attenuator and then insert that between your aerial point and the aerial point on the Freeview box and then mess around with the attenuation setting until Five and related channels come in loud and clear.

This one from Satcure at £5.95 (CONNECT 86) ought to do the job:-

See www.satcure.co.uk/accs/page15a.htm

You will also need another coax lead to go from the attenuator to the Freeview box.


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## algordon (Apr 1, 2004)

Thanks, Pete77, I'll give that a go and see how I get on. One last thing, though - any thoughts on why this problem is so intermittent? For months as I said earlier, we had no problems at all, this latest thing thing has been pretty recent.

Sorry, one more thing - when it's the box that's at fault - the FV box, I mean - what are the signs - for future reference?

Thanks again.


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## Pete77 (Aug 1, 2006)

algordon said:


> Sorry, one more thing - when it's the box that's at fault - the FV box, I mean - what are the signs - for future reference?


No picture on any channels would be a sign your Freeview box was dead.

You have now tried several different boxes so the problem can't possibly be with the boxes.

I'm surprised you haven't yet had your expensive aerial installer back to test out why their handywork appears to possibly be deficient.


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## AMc (Mar 22, 2002)

As Five etc use a less resilient modulation (as Pete77 explained) they are also more prone to impulse interference. This happens when mopeds, buses, badly suppressed fridges and central heating kick in. It causes a few blocks and garbles the sound.
I get this a bit on Five and its friends and it's worse in cloudy wet weather - my Five has been pretty clean for months but since the weather got wetter I'm seeing it a bit more frequently.


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## Pete77 (Aug 1, 2006)

AMc said:


> As Five etc use a less resilient modulation (as Pete77 explained) they are also more prone to impulse interference. This happens when mopeds, buses, badly suppressed fridges and central heating kick in. It causes a few blocks and garbles the sound.
> I get this a bit on Five and its friends and it's worse in cloudy wet weather - my Five has been pretty clean for months but since the weather got wetter I'm seeing it a bit more frequently.


But in theory the ITV multiplex uses the same less resilient but higher capacity 64QAM transmission format as well.

Yet here at my home location ITV has always been one of my most robust multiplexes and SDN my most unreliable, yet at my mother's house SDN channels are always fine and yet the ITV multiplex is not even decipherable.

Ultimately local conditions have as much to do with things as the signal transmission format.

I am always surprised at the number of people readily willing to readily shell out £200 or more for a Freeview aerial upgrade when (a) that is more than www.freesatfromsky.co.uk and a lot more than the new £75 PayOnceWatchForever Sky Freesat product. (b) It is clear that in time the free Sky channels will disappear off Freeview and it will be little more than the BBC, ITV, C4 and Five channel ranges with some additional +1 variants (c) in 2012, or earlier in many area, when analogue is switched off the aerial upgrade will no longer be necessary in most cases due to increased DTT power levels.

Whereas due to the launch of BBC Freesat and the lack of significant capacity restraint issues the number and diversity of FTA channels on a Sky Freesat installation is bound to increase further over time.


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## TCM2007 (Dec 25, 2006)

Pete77 said:


> I am always surprised at the number of people readily willing to readily shell out £200 or more for a Freeview aerial upgrade when (a) that is more than www.freesatfromsky.co.uk and a lot more than the new £75 PayOnceWatchForever Sky Freesat product. (b) It is clear that in time the free Sky channels will disappear off Freeview and it will be little more than the BBC, ITV, C4 and Five channel ranges with some additional +1 variants (c) in 2012, or earlier in many area, when analogue is switched off the aerial upgrade will no longer be necessary in most cases due to increased DTT power levels.


Remember a single aerial will supply every TV in the house, whereas the price you quote is for a single TV.


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## Pete77 (Aug 1, 2006)

TCM2007 said:


> Remember a single aerial will supply every TV in the house, whereas the price you quote is for a single TV.


Not so TCM.

A single decent high spec Freeview aerial will only supply a signal tv point in your living room unless you pay extra to have the output from that aerial split and routed to points in other rooms.

I have asked around for quotes and the cost of a single Sky dish with appropriate LNB then split to four points and the cost of a Freeview aerial split to four points is basically the same at around £300+. However if you want Sky and Freeview compatibility to four points in the house you are probably looking at say £450 or more.

My point is that if you don't have an adequate Freeview signal due to trees or transmitter distance or obstructions then you have to spend around £200 for a decent upgraded Freeview aerial on your chimney on a big pole but that in this same situation Sky Pay Once Watch Forever only still costs £75.

So as I say getting a decent Freeview signal if you don't have one now costs a lot more on Freeview than Sky and the costs of a multi distributed Sky and Freeview set up (which a professional Sky installer will only do on a non Sky funded install) is about the same for DTT and satellite. And its clear to me that in the next two to three years Freeview is going to become dominated by just channels from BBC, ITV, C4 and Five as a medium for people content with no wider choice, instead of being a lower cost wider choice reception mechanism as it could have been.


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## TCM2007 (Dec 25, 2006)

Pete77 said:


> Not so TCM.
> 
> A single decent high spec Freeview aerial will only supply a signal tv point in your living room unless you pay extra to have the output from that aerial split and routed to points in other rooms.


My assumption is that you are talking about upgrading the aerial, since that's what you said, not the distribution system. The distribution wiring will all be in place already, so there is no extra cost. If you are adding a dish, obviously that distribution wiring would not be in place, plus you'd need a Sky box for each TV, which is much more expensive than a Freeview box for each TV.



> My point is that if you don't have an adequate Freeview signal due to trees or transmitter distance or obstructions then you have to spend around £200 for a decent upgraded Freeview aerial on your chimney on a big pole but that in this same situation Sky Pay Once Watch Forever only still costs £75.


The upgrade required (if it is required) is usually about the number of elements and the vertical or horizontal polarity, not sticking it on a pole.



> So as I say getting a decent Freeview signal if you don't have one now costs a lot more on Freeview than Sky and the costs of a multi distributed Sky and Freeview set up (which a professional Sky installer will only do on a non Sky funded install) is about the same for DTT and satellite. .


You're forgetting the cost of the STBs. £110 for a Sky box, £25 for a Freeview box. If you have say four TVs (not unusual) that makes quite a difference!


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## Pete77 (Aug 1, 2006)

TCM2007 said:


> My assumption is that you are talking about upgrading the aerial, since that's what you said, not the distribution system. The distribution wiring will all be in place already, so there is no extra cost.


A 25 year old distribution system that works for analogue tv is often inadequate for Freeview due to the weaker DTT signal with its greater loss charcteristics. No aerial installer is going to be prepared to work with 25 year old signal boosters and coax on their last legs. They are going to want to replace the whole lot.



> The upgrade required (if it is required) is usually about the number of elements and the vertical or horizontal polarity, not sticking it on a pole.


My mother's aerial is a single bar thing with elements down it on a very long poll due to the surrounding tree cover. It was fitted in the mid 1970s and the poll it is on is visibly corroded looking up from the ground. Any aerial fitter who goes up there is going to recommend the whole set up is replaced while he is risking his neck and you are paying a £150 labour charge. Now of course perhaps you don't live in an area with trees or live only 2 miles from the relevant Cornish transmitter or perhaps you only put the same price on your neck as the poor unfortunate Rod Hull did.  



> You're forgetting the cost of the STBs. £110 for a Sky box, £25 for a Freeview box. If you have say four TVs (not unusual) that makes quite a difference!


Second hand Sky Digiboxes regularly sell for £10 to £20 on Ebay and are perfectly serviceable but you may or may not need to pay Sky £20 for another viewing card if the box comes with no card or an out of area card. Sky has gone to rather a lot of trouble to force Ebay to actively delist auctions for Sky Digiboxes that promote a Sky viewing card as being included. Of course probably some time next year the concept of FTV channels with no subscription needed but a viewing card required will disappear when C4, E4, More4, Five, Five US and Five Life have their signals unencrypted.

You seem to take a positive view on the easyness of Freeview because you live in an areas where you get all the channels. If you lived in an area where Freeview coverage is marginal and some of the stations break up you would probably feel differently about matters.


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## TCM2007 (Dec 25, 2006)

Pete77 said:


> A 25 year old distribution system that works for analogue tv is often inadequate for Freeview due to the weaker DTT signal with its greater loss charcteristics. No aerial installer is going to be prepared to work with 25 year old signal boosters and coax on their last legs. They are going to want to replace the whole lot.


Who said anything about a 25 year old system??? Talk about moving goalposts!



> Second hand Sky Digiboxes regularly sell for £10 to £20 on Ebay and are perfectly serviceable


Secondhand? There go the goalposts again!

I'm sure that you've done the calculations and found that in your mother's case Sky makes sense, but you then widen it to be a general statement that you can't imagine why anyone ever goes for Freeview. The answer is, becaus enot everyone's circumstances are identical to your mother's.


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## Pete77 (Aug 1, 2006)

TCM2007 said:


> I'm sure that you've done the calculations and found that in your mother's case Sky makes sense, but you then widen it to be a general statement that you can't imagine why anyone ever goes for Freeview. The answer is, becaus enot everyone's circumstances are identical to your mother's.


In many, many cases there is only one coax tv point in a house with an old aerial and the old aerial is not able to pull in all the channels on Freeview (no matter what box is used).

In all of those cases upgrading the old aerial will be much more expensive than Sky Pay Once Watch Forever at £75 if the aerial is up on a pitched roof and so danger money is required for a professional aerial contractor to change it and/or the old coax cable that runs to it. Unless of course you are prepared to play Russian Roulette on a steep and slippery roof as poor Rod Hull did.

I think it is in fact you who is moving the goalposts to ensure that you win the argument.


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## TCM2007 (Dec 25, 2006)

Pete77 said:


> I think it is in fact you who is moving the goalposts to ensure that you win the argument.


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## mikerr (Jun 2, 2005)

Back to the OP's problem, it could also be due to the fact that "old" coax - the brown stuff - is not well screened, so its vulnerable to any unsupressed motors and interference. The newer - generally black - CT100/WF100 cable is fully screened

On analogue channels this results in short periods of picture degradation - black or white flecks or snow, for a second or so, but with digital you get a more annoying 1-2 second picture freeze.


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## Pete77 (Aug 1, 2006)

mikerr said:


> Back to the OP's problem, it could also be due to the fact that "old" coax - the brown stuff - is not well screened, so its vulnerable to any unsupressed motors and interference. The newer - generally black - CT100/WF100 cable is fully screened
> 
> On analogue channels this results in short periods of picture degradation - black or white flecks or snow, for a second or so, but with digital you get a more annoying 1-2 second picture freeze.


Indeed so.

This is precisely why I was trying to make the point to TCM that his assumption that you could simply update an old distributed coaxial system by just replacing the aerial that feeds it was not correct.

I have been quoted for making the distributed communal system serving my flat and the other flats here more robust for Freeview and it requires at least replacement of all the boosters and the aerial that feeds it but quite probably the replacement of all the coaxial too.


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## mikerr (Jun 2, 2005)

Not quite - old coax is more susceptible to interference, 
but that matters only if there is a lot of interference, 
the cable doesn't in itself introduce any greater loss of the actual signal than newer CT100.

Walls also do a good job of shielding


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