Ch4 tuning problems (nr Manchester)

[Martin Brown]

This is an odd one. My parents TV has been acting strange ever since digital switchover. Channel 4 has vanished and has been replaced by a Welsh version with a noise to signal ratio rather than SNR. There is enough picture gets through sometimes to recognise that it is C4 but not enough to be watchable. Looks like Picasso on a bad acid trip.

The channels detected with QOS and SNR out of 10 are

1 BBC1 Ch62 Q10 S7 2 BBC2 Ch62 Q10 S7 3 ITV1 Ch59 Q10 S7 4 S4/C Ch39 Q01 S3 5 Ch5 Ch59 Q10 S7 8 C4 Ch39 Q01 S3

Both these versions of C4 are completely unwatchable due to massive picture breakup and ultrasonic clicks and pops. Neighbours report similar problems and also phantom "new channel" retune warnings at startup that add Welsh stations at terrible signal to noise.

This has only happened since digital D day. Any ideas what is going on? I had expected it to be a simple matter of retuning but I have tried several times no without success. All other channels are Q10 S7.

My mum likes to watch Countdown in the afternoons so this is a big one!

I will force a full manufacturers reset next but before I do that and lose all their preferences I thought I would ask in case it is a known problem and C4 is off the air near Manchester for some reason.

Thanks for any enlightenment. Somehow I can't imagine that the Welsh nationalists have teamed up with GMC to block Channel 4 transmissions or punish Panasonic owners but at the moment it certainly looks like it.

The TV is a Panasonic 27" LCD model TX32LXD700 old enough to still have an analogue as well as digital tuner. I will retry with a different set top box tuner but since others in the neighbourhood report wierd behaviour on C4 and Welsh programs I suspect it is systemic rather than a fault in the set. Aerial is very high and pointer at WinterHill. All other channels appear to work OK - only C4 is AWOL and Fubar :(

Thanks for any enlightenment.

Regards, Martin Brown

[Dave Plowman (News)]

Do a factory reset and try again. However, are you sure the aerial is ok and pointing at the correct transmitter? Sometimes in marginal areas you get a better signal from the wrong transmitter. And those marginal areas aren't just distance from the transmitters. A look at other aerials in the local area might give a clue if this is a problem.

[Dave Liquorice]

If you extend the line house > winter hill does it carry on towards Wales?

As Ch4 is so rough and the others so good bung in an attenuater to nagger it even further and hopefully the Ch4 from Winter Hill will be found in preference. WTF the set is insisting on using the crappy one is anyones guess, have you looked in the 800 or 900 channel range to see if Winter Hills Ch4 is there? I think you can reassign channels from there to thier "proper" position.

It's a known problem and there have been discussions about this in the past, not sure where, may have been in here.

[Brian Gaff]

It was in on of the digital groups. Yes, some sets are now too sensitive since the powers went up. Even here close to Crystal Palace I get some phantom stations up in the high numbers from a loft aerial.

No idea where they are from, but they are predictably copies of shopping channels. Brian

[Mike Tomlinson]

In article , Martin Brown writes

I had exactly the same problem, it was the PVR picking up the Welsh relay at Storeton as well as Winter Hill, so I was getting BBC1, BBC1 Wales, ITV1, ITV1 Wales, S4C, etc.

I cured it by putting 18dB of attenuation in the aerial lead, that stopped the PVR's automatic tune picking up the Storeton channels.

An alternative is to do a manual tune and select the channels from Winter Hill. To do this you need to know the channel allocations. Plug yer mum's postcode into this:

see what channels she should be receiving. The Winter Hill channels are:

50 - BBC A 59 - D3&4 54 - BBC B HD 58 - SDN 49 - ARQ A 55 - ARQ B

54 is HDTV, you'll need an HD decoder for that.

[GB]

Stoopid question, but what is reception like on C4 + 1?

[Martin Brown]

Only Ch4 is missing but loss of Countdown is giving me a LOT of grief.

My parents are elderly pensioners - so is there any chance of beating the living daylights out of that stupid pink robot that claimed digital switchover would be dead easy and making them sort it out?

I don't understand the acronyms but I cannot see any Channel 4 signal at all even with manual tuning (which on this specifc digital Panasonic is tedious beyond imagination). Am I missing something here or is the behaviour just totally perverse when the signal level gets too high?

I can get my wife to bring another tuner down at the weekend and my selection of attenuators. Seems odd that you have to hobble the front end to make it behave now the power has been increased!

I could have the aerial repointed at Saddleworth (nearer) but ISTR they had severe multipath ghosting on analogue in that direction. Looking across all the skyscrapers and more have been built since then.

All the remaining local terrestrial aerials which have not fallen off or left hanging off the chimneys are facing Winterhill. Most are on satellite or cable which are both available in this urban setting.

It would be easier to install a satellite except changing anything is met with *enormous* resistance. They still hanker after Ceefax (and to be honest so do I the new red button is a PITA for data services).

Any pointers to earlier discussions of this digital MFU would be greatly appreciated. It seems a bit crazy that they cannot get major connurbations like Manchester with correct signal levels to work!

It was all working perfectly for five or six years prior to D-day :(

Regards, Martin Brown

[Martin Brown]

I had forgotten that there was a Ch4+1. It isn't there either nor is it's Welsh Doppelganger cubist breakup version with clicks and pops.

We don't watch TDTV at home so I am unfamiliar with what channels

*should* be there. And anyway they do seem to vary with region...

Regards, Martin Brown

[harry]

I have a Panasonic as well. I have had to install an aerial amplifier. I think it's because I live in a hilly area. I now get around seventy channels. Most of it is shit.

Consider too getting "Freesat" if reception is really bad. Even more channels mostly the same but not all.

[Martin Brown]

Are there any FreeSat tuners that map the Satellite channels down onto the same set of numbers as TDTV? In particular for aged parents having to remember to press 101 to get 1 and 102 to get 2 is very unhelpful.

(any that reset everything to default again every retuning do not count)

It is very hard to sell all the extra channels as an improvement since they never seem to look at anything that they didn't have on analogue... Except the rolling News on 80.

Regards, Martin Brown

[Java Jive]

As others have suggested, it seems likely that you are picking up Storeton, which transmits both English and Welsh channel sets. Put the relevant postcode into my TV Aerial Alignment Calculator, under transmitters choose 'Find the nearest', and check whether Storeton seems a likely candidate. Don't forget that many aerials pick up appreciable signals from side lobes and even sometimes through the back.

you d> This is an odd one. My parents TV has been acting strange ever since

[The Other Mike]

You might find a manual tune gets overridden by a later autotune triggered by a channel renumbering or finger trouble by the user.

Filtering the aerial signal can be useful in eliminating any unwanted channels (it can be a better solution than a simple attenuator)

I've used Optima bandpass filters before

(not from the following supplier but they at least they still carry the full range unlike the supplier I used previously)

be worth posting to uk.tech.digital-tv ?

[Roger Mills]

As others have said, you're picking up Ch4 from the wrong transmitter because the auto tune is finding the wrong one first.

Again, as others have said, the best solution is to do a manual tune, having first determined which UHF channels are carrying the desired MUXes.

Meanwhile, have a look on the TV in the 800's. You may well find that the proper Ch4 is somewhere up there rather than at 4. You might even be able to juggle the numbers without doing a re-tune.

[Dave Plowman (News)]

Yes - something at the back of my mind says there was a problem with some Panasonic sets which can be fixed. Trying an external tuner would prove this.

[Bill]

In message , Java Jive writes

I'd be quite surprised if someone near Manchester was affected by Storeton's Welsh transmissions, but this made me try to look at whether the transmissions from this site were directional. As usual, I looked but failed to find. Don't they do maps of transmitter service areas any more?

I've recounted before my problems with Storeton. From here it's almost directly in line with Winter Hill, just down the road and pumping out Welsh on adjacent channels and with the same polarity. The tuners in various devices I've seen all behaved differently, and trying to get a set top box from a local Curry's that actually worked and was usable was a complete nightmare. One elderly relation ended up with a third box, and a conversion chart from me with things like BBC1 = Channel xxx, BBC2 = yyy and so on. I think in practice she just uses the up/down buttons until it speaks English and the presenter looks like Fiona.

[Mike Tomlinson]

In article , Martin Brown writes

On D-day they boosted the transmitter power for the digital channels from 10kW to 100kW. It's too high for some digiboxes to cope with.

[Andy Burns]

The radiation patterns (per mux) of the smaller transmitters were released under an FOI request, e.g Nottingham

releasing information for the larger transmitters (Including Storeton) were refused as not in the nation's interest

most of the rumours and speculation, the radiation maps on ukfreetv are a useful feature.

[GB]

Countdown is also on ch 47. How about that one?

[Terry Casey]

As has been pointed out before,

The Winter Hill channels are:

50 - BBC A 59 - D3&4 54 - BBC B HD 58 - SDN 49 - ARQ A 55 - ARQ B

When you do a retune, the set scans from Ch21 - Ch68.

If it finds valid signals, it stores them, even if they are from the wrong transmitter. If duplicates (from the local transmitter) are found later on (ie: on a higher channel) these should still be stored but, rather than over write the original allocations, they are added above everything else - usually in the 800s, as others have said.

In your case, the unwanted Welsh signals are seen before the Winter Hill ones because they are on a lower channel - 39 - whereas Winter Hill muxes do not start until ch49.

There is a simple solution to this: unplug the aerial and do a complete scan. As the scan progresses, it should indicate the number of the channel being scanned.

Wait until it reaches Ch40, then plug the aerial back in so that it picks up the local muxes from Ch49 up ...

As has been said before, a large attenuator in the aerial feed may achieve the same result without unplugging the aerial.

If you have a selection of attenuators and a good local signal strength, it might be useful to experiment to see if you can find a value which stops the Ch39 mux from being recognised but doesn't cause any deterioration of local reception.

Leave this plugged in to provide a permanent solution as the set can then be retuned in the future without the problem recurring.

Note: you say the problem only started at DSO (because the unwanted mux power was increased). If the local muxes pre-DSO were ok, as these have also increased in power, it will be obvious that you have surplus signal levels to play about with ...

[Mike Tomlinson]

In article , Terry Casey writes

I believe some DTV boxes will, if they detect channels from more than one transmitter, offer you the option to select the one you wish to use. But I haven't actually seen one.