We are getting very poor freeview reception in this part of Suffolk (Southwold). All BBC channels are fine (thank god) but everything else is suffering from freezing and general 'blockiness'. Is there a website that you can input said postcode and it informs one of prevailing signal quality? Never needed this previously as signal strength has always been pretty robust.

Thanks for any advice.

No, that's not possible - as such a problem is almost certainly local to you - most probably a poor aerial system?.

What signal strength/quality readings are you getting on the TV? - there should be an option somewhere to display that data.

However, you might try:

http://www.bbc.co.uk/reception/

This 'might' tell you if there's any work going on to your local transmitter, but it's not really very well updated or helpful.

No website can predict with total accuracy what signal you should be receiving. There are too many variables involved for that. You could try the DigitalUK website (just stick .co.uk on the end) and enter your postcode and house number into the Coverage Predictor and tick Detailed View.

However if you used to get a decent signal and now are not that suggests something has happened to your system. Common causes are the aerial moving off beam in the wind (assuming an outdoor aerial), rain water ingress into the terminal block on the aerial degrading the connections, a split in the outer insulation of the cable outdoors letting in rain water degrading the cable, connections working loose or interference from some source (poorly screened cables tangled up behind the telly is often to blame).

So I would check out your system as far as is practical to look for any issues.

(Maybe this should be in the freeview section)

Obvious checks to what has changed.

Has the aerial moved?
Is the cable damaged/
Are the plugs/ leads (to and from aerial) inserted correctly?
Have you connected anything else to you tv recently (ie Amazon Firestick)?
Have you got a modem or router close by?
Do you have other tv's 'daisychained' (connected to the same aerial) together?

As far as I can see, from a check in your area, there are no service issues or transmitter work happening in your region (Anglia).

This page tells you the current levels expected on each mux and expected levels in 2017.

http://www.digitaluk.co.uk/coveragec...cc4aqt47t3aad6

It is NOT though indicative of engineering. Nor is it a guide to signal levels on each channel.

So the problem lies somewhere in your setup.

You can see if anyone else has the issue.
Use a different tv (borrow one perhaps), or try a pvr and see how that performs.
This would narrow it down a bit as to whether it is an aerial, tv or location issue.

Wolfbane gives (or certainly used to give) an indication of signal level based on topography. However, the results are calculated rather than being taken from actual field strength measurements so it isn't that reliable. My local transmitter is Winter Hill. Wolfbane tells me I need an amplified aerial when in reality I have a very low gain aerial (a Log Periodic) and still have enough signal to passively split 3 ways.

If there's no new gear and nothing has changed with the wiring inside the house then it is most likely to be water ingress is the problem.

The BBC and ITV muxes should all give the same kind of signal strength. If the aerial was out of alignment then I would expect them all to suffer by a similar amount. A kinked or broken cable can cause a notch filter that blocks certain frequencies. That might wipe out one or two mules but not all. Water in the connections or cable will reduce the signal level. I wouldn't rule out a loose aerial plug in the back of the telly or at some other signal junction.

One of the biggest causes of reception issues is poorly screened coax flyleads. Those moulded ones supplied free with gear or available cheap at supermarkets and DIY stores are prone to picking up interference from household power supplies.

As I have said many times check for anything obvious then ask your neighbours if they are also having problems BEFORE contacting any forum. Otherwise all you are going to get is wild speculation.

Sorry for the delay in replying and thanks greatly for all of the links and advice generally.

This problem seems a particularly difficult one to sort. We are only usually here at weekends so unable to relay information back on a daily basis. Re the equipment here is a TV (receiverless), 2 Panasonic DVD recorders (each with freeview tuners) and a Humax PVR. The TV shows all BBC programmes (Multiplex 1?) with a strong signal (Strength 80% constant, Quality 100% constant) on all equipment. On all other non-BBC stations (Mux2?) there is freezing and blockiness and occasional blank screen with message Poor quality signal/signal scrambled - (Strength 80% constant, Quality 20%-100% fluctuating). All of this equipment is SD.

In the loft there is a Labgear amplifier. I thought this might have failed and the BBC signal was sufficiently strong to not need the amplification. But upon switching this off the BBC channels show no image and a message: Bad signal.

There is nothing discernibly wrong with the aerial; it points the same way that it always has. But if this was out of position would the beeb channels also not be affected?

Most other neighbours are receiving Sky, BT or Virgin supplies so cannot be compared. But crucially my immediate next-door-neighbour has freeview which appears entirely problem-free. Mystifying.

There are any number of influences and while some have already been mentioned, like transmitter maintenance and misalignment, there are others too such as ailing amplifier, high pressure weather, 4G interference and so on.

You could call in a relevant local firm to come and look at your aerial set to see what the causes are but another option would be to spend that money instead on an entirely non-subscription Freesat set up for a one-off cost. I have both Freesat and Freeview and my own experience is that the Freesat signal is far more reliable and resilient. In any event, I hope that you find a solution.

http://www.freesat.co.uk/what-is-freesat

http://www.freesat.co.uk/channels

Thanks for the update, there's some useful information there.


I agree about the loft amp. If that was failing then you'd lose the lot, or at the very least you'd have a massively reduced signal level right across the board; certainly nothing like 80% S and 100% Q for just one mux but nothing on the others.

Speaking of muxes, depending on whether you're receiving from a Freeview Lite- or a full service Freeview transmitter you'll get either three or 6 muxes. If you were receiving stations such as ITV3, QVC, and The Jewellery Channel then you're in a 'full service' area, so 6 muxes.

From what you've described there's one thing that I don't think has been discussed, and that is Freeview retunes.

The Government is intent on selling off more chunks of the TV frequency spectrum to mobile phone operators. The result is that there's a lot of tinkering going on with the channel allocations on the transmitter network. The trend is to push the muxes to lower transmission frequencies. Up to a few years ago we used to use from c21 to ch 68. Then the Government sold off 61 to 68 for 4G so any transmitters with muxes in that space had have new channels allocated. The challenge is that transmitters overlap so it's not as easy as putting the BBC1 mux on ch21 for everyone because there would be interference. That's why with new TV installations the tuner scans the whole band and then you select what TV region you want as a preference.

It's entirely possible then that your local transmitter has had its channel allocations altered as part of this rolling programme to facilitate the bandwidth sell off. So the first thing to try is a retune, but it has to be a "from scratch" retune; a simple refresh won't do it. That's because on a refresh the TV tuner simply looks at the mux locations it already knew about. That's no good if the mux has been moved to a new frequency. Your TV menus should give you the option to do a "first time install" or do a factory reset. If it is a full reset then remember that the TV will also wipe out any picture settings you might have tweaked., so if you have set up contrast, brightness, colour, sharpness etc to your own preferences then make sure to write then down before doing the reset.

There's another aspect to these retunes, and it is to do with the type of aerial. Aside from design, aerials fall in to two categories; there is wideband and there is group aerials.

Wideband aerials pick up the entire frequency range and have moderate sensitivity. Group aerials pick up a much narrower range but are more sensitive as a result. If you have a group aerial but the channels you now receive have moved outside of the antenna's optimum range then it will be in effect hard of hearing at those frequencies. Group aerials are identified by the colour of the end stops used. Black is for wideband, then the narrow band aerials are red (Group A), yellow (Group B), green (groups C & D) and brown for Group E.

Turning the amplifier off effectively cuts the signal, so u lose everything. To see what the raw signal is like you have to bypass the amplifier.

Beware that even with a strong signal, with digital, if there is a damaged cable, or wobbly connector, the signals for the various channels will take a hit. The strongest ones may make it through, but others won't. It's a bit like trying to do a print out from your PC while holding the USB jack half out the socket.
U may find that touching, moving each aerial plug about a bit or more specifically the cord where it enters a plug, while the signal bar display is on the tv screen reveals the problem.

U can get a ''freeview signal meter'' from wilkinsons, about £10 i think. Same principle as cheap sat meters, ie just shows modulation amplitude (and needs internal battery, of course, unlike sat meters which get power from receiver input). Also, just like cheap sat meters, these cannot show the reception error rate, which is the ''crucial thing'' ...........

It's all about ''the digital cliff''. If your reception occasionally fails, in poor weather, or from passing motor vehicle interference, or your fridge/freezer, etc, then the remedy is to increase signal to noise ratio. As noise is fixed at receiver input, this means better aerial, lower loss cable, masthead preamp, some combination of these, or possibly consider satellite reception instead ......... digital reception is a right bugger, because of the ''threshold cutoff point''............

Note that, if bbc is ok, these channels are broadcast at ''greater strength'' (lower data rate) than itv, and therefore just a small signal to noise improvement might be enough .......

Next time you are there, by pass and switch off the amp, you will probably need a back to back coax coupler available from Wilko, B&Q, Screw fix etc so the aerial now just feeds your main outlet. Unplug everything from the mains except one receiver, perhaps the Humax and the TV, which you say is tuner less and I assume is an old analogue model with a SCART connection, and see if it all works. If it doesn't you have an aerial fault and may require it to be replaced, if it does reintroduce things one by one, starting with the amp, until you find which item is causing the problem. I'm afraid you will have to help yourself in this matter otherwise speculation from forum members is likely to be misleading as they haven't enough to go on.

You didn't tell us at first about the amp, is there anything else we should know, tall nearby trees having grown higher for example?

I'd be very surprised if you manage to find error rate displays (BER) on any terrestrial DVB-T2 meter under £100.

Those £10 meters really are a waste of money too. For a start they're far too insensitive for Digital TV signals; the first LED doesn't light up until 50dB signal level is reached! Then the signal level steps of 10dB increments are a joke. That would be the equivalent of rotating the aerial through 90 degrees away from the transmitter. I'd have more faith in the TV's Q and S displays.

One thing I noticed is that you are using a humax Pvr . Has it done a retune replaced the main transmitter with a local relay on some multiplexes . I suggest this because when there has been a freeview retune which the humax box does automatically I have had to do a factory reset and a manual tune on my mums because of it finding the wrong transmitter.

All his equipment is SD, I don't think any of Humax's SD PVRs auto retune, certainly the 9200 doesn't. I suspect the rest of his SD equipment doesn't either.

Back for the weekend and just to bring this issue up-to-date we are now mostly sorted. Surprisingly, it was the Labgear amp. Replacing the existing with a new equivalent model has eliminated the breaking-up and freezing etc. It looks like the reason we were still able to receive the BBC channels problem-free was that the amp had failed partially so was insufficiently able to boost the weaker signals from the other channels but still capable with the beeb broadcasts. The TV produces a reasonable BBC image when bypassing the amp (as advised) but the sound is reduced. Perhaps the Tacolneston transmitter has a greater disparity between BBC signal compared to the rest? I suppose I could try opening up the old amp to see if there are any giveaway signs though I would be a bit out of my depth here.

One thing that is noticeable, however, is that upon retune the new amp is only ‘pulling in’ 21 TV channels excluding The Horror Channel, Movie Mix and QVC for instance. I will check later as to what muxes these are on. Previously we had about 40 channels but the web says there is some work being undertaken on the transmitter. So perhaps the ‘lost’ stations will reappear over time.

Thanks for all of the constructive suggestions and links that have been added to this thread. I will try to deal with some of the points raised.

TelevisionUser: Actually your Freesat installation sounds very wise so we are likely to pursue this over the coming weeks. I like the sound of a more dependable system. That said we have never really had problems with Freeview here. Thanks for the links.

Chris Frost: We did try retunes but to little avail. The PVR seemed to pick up all stations but not be able to show an unaffected image on the non-beeb channels. The Panasonic recorders did not even grab these stations on retuning. You make some very interesting comments about the ‘squeezing’ of the freeview bandwidth. The machines al show 21-68 graphic when retuning but this is now misleading. It is a wideband aerial by the way.

David(2): See comment in opening paragraph. Good point but all of our connections seem completely free of corrosion and there is no sign of knackered sheathing on any of the coaxials.


It looks like this explains our situation.

anthony david: Did what you recommend except that we required an F socket->coax socket connector as the new amp has F plugs. Yes the TV is an old 32” Hitachi plasma that came with an analogue receiver. I reckon it is about 2004. Like the Humax (a 9300-T with auto retune incidentally), and the Panny recorders. All this stuff came down from London and works reliably well, albeit on SD. They are all connected with Cambridge Audio scart leads and component cabling. Unclear as to how much longer these items will last but no worries, really, if they pack up as they have done us fine. We have a larger HD TV in a different room (receiver non-operational) driven by a Sony blu-ray for watching boxsets etc. Unfortunately getting the coax supply to this part of the property is rather complicated but we hope to get round to it reasonably soon and hence probably using the Freesat idea proposed by TelevisionUser.

Very pleased that you solved your problems and thank you for telling us so, many others just can't be bothered to do that. Sounds like your signal levels are low on some multiplexes if you are not getting all the channels you should, go through the advice given by others earlier as a properly operating aerial system should cope with most transmitter power reductions which tend only to be in the daytime anyway. Neither aerials nor their cables last forever, the weather takes its toll I'm afraid.