Panasonic DMR-EX97 Recorder - Lost HD channels

Sony65

Active Member
Hi, Recently lost all my HD channels on my Panasonic Recorder and after a few retunes with/without aerial connected they came back but have now vanished again. After a few more retunes they appear on the Guide but No Signal when selected. Interestingly, sometimes not all the HD channels have returned just the main ones but not QUEST HD, QVC HD, etc... Then a couple of days ago my TV lost all HD channels but after a full retune they have come back but occasionally I do get a small amount of pixilation but that soon clears. I originally thought the tuner in my Panasonic was the culprit but then when the TV started playing up I thought it was our communal aerial. I had this checked out yesterday by the aerial company but they said that the signal was fine. Appreciate if anyone else has had a similar problem. Cheers.

Cheer
 

Gavtech

Administrator
As this is likely a Freeview reception issue rather than a problem with your device I'm moving it to the Freeview section. You will get more focused help there.

You will likely get asked which area you are in or which transmitter you receive from.

Something to note - in cases like this which look to be reception problems - DO NOT RETUNE.
If you retune and cannot receive those channels, at the time, for any reason, you will loose the channel placeholders and thereafter will not receive the channels even if the reception problem goes away. (... until you do another successful retune)

If you leave the tuning as it is, the channels will return when the reception problem is resolved, whatever it may be.
 

Gavtech

Administrator
Another point occurs to me;

Have you 'moved' any HDMI cables recently?

HDMI cables can emit an interference which can knock out the reception of HD channels particularly - in very bad cases it can knock out all reception - but HD is most susceptible.

So, HDMI cables should be kept as far away as is practicable from UHF cables, or if the matter cannot be resolved , try other HDMI cables.

Some cables have the problem worse than others. Cheap or expensive makes no difference.
 

mikej

Well-known Member
The first thing to do is check your coax sockets, connections, cables and plugs - are they all good quality and sound ?

Which part of the UK are you from ? There was a fairly major re-tune event for the Winter Hill transmitter (which serves the North West) recently that saw a large number of channels moving frequency. These new frequencies are now outside the range picked up by certain types of aerial, which has lead to a lot of people losing channels.

BBC Four HD, BBC News HD, Quest HD (and others) are provided on COM7 / UHF Channel 55 from Winter Hill. This one hasn't moved recently but it has been problematic for me (and others) in the past, when I could only receive it sporadically at different times of the day and often with pixelation. I used to receive it at a much lower signal strength than the others, but upgrading the coax from the loft to the lounge boosted the strength and seems to have solved the problem for me.

Even if you're not on Winter Hill, you might find that your transmitter has had similar re-tune events and I believe that COM7 is transmitted on UHF 55 in other parts of the country too, so your issues might be similar.

If you're not sure which transmitter you're on, put your postcode and house number into the checker on the Freeview site and hit 'Check', scroll to the bottom of the channel list and click on 'Detailed View'. This will show you your most likely transmitter and the top 'Coverage Prediction' table will also give you a list of UHF channels ('N' in the table) if you want to try a manual tune or check your signal strengths.

Go to the manual tuning option on your Panasonic PVR and try selecting the 'BBC A' frequency from the table, as this is likely to be one of the stronger frequencies you can receive. Then compare it to the 'COM7 HD' frequency from the table - you might find this one to be lower. It's amber in the prediction table for me, hence my previous problems with interference.

The other option for investigating the signal strengths on your Panasonic PVR is via the 'Signal Condition' (or similar) option in the tuning or set-up menus, if it has one. This might be limited to channels you are already tuned into though, hence my suggestion for going down the manual tuning route.
 

Sony65

Active Member
Thanks for your response however, this morning turned on TV at around 10.30am to check HD channels and there was immediate pixilation and when I checked Signal Quality it was around 9-10/100. Signal Level was 100/100 but as the day went on the SQ increased and is now around 43/100 which appears to be sufficient for HD reception. My Panasonic on the other hand shows most HD channels in the guide but not available when selected. My cables etc.. are in good condition and have not been fiddled with since installation but I did check connections etc.. As previously mentioned I did have my Communal aerial checked out and is receiving a sufficient signal for HD etc.. I live in Essex so pick up Crystal palace I believe?
 

TJT1

Member
I wonder whether you have too much signal as that can cause clipping in the tuner and total loss of picture.
 

Sony65

Active Member
Funny you should mention that as the aerial guy said I had a very strong signal and fitted something on the end of my aerial cable at the wall plug which apparently reduces the signal!! But my Panasonic Recorder is still without HD channels. Could it be the tuner inside my Recorder causing it and on top of that notice that it takes a little while to boot up from start but can't imagine that is relevant?
 

TJT1

Member
It is an attenuator.
Is the signal strength still 100?
Possibly the tuner but FAR more likely to be something else.

Is the problem with ALL HD channels? There are 5 'main HD ones' BBC1, BBC2, ITV, CH5, CH5. These are all on the same multiplex (BBCB). If you can receive any one of them, you should be able to receive them all.
There are also BBC4 HD, QVC HD, QVC Beauty HD, RT HD, Quest HD, CBeebies HD and a few others on Com7. This is the one that is most likely to give you problems.
 

Sony65

Active Member
So, again this morning no HD channels on my TV but a few hours later back they came but Signal Quality is now around 32/100 and Signal Level is still 100/100. My Panasonic Recorder however still hasn't picked them up again so not sure whether to do a full retune or not? Interestingly, my TV only picks up the main HD channels and not the likes of QUEST HD, QVC HD etc.. which TJT1 was curious about. My initial feelings was that the Tuner in my Panasonic was the cause as the TV signal goes through this before it hits the TV but confused now...
 
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Gavtech

Administrator
So, again this morning no HD channels on my TV but a few hours later back they came but Signal Quality is now around 32/100 and Signal Level is still 100/100. My Panasonic Recorder however still hasn't picked them up again so not sure whether to do a full retune or not? Interestingly, my TV only picks up the main HD channels and not the likes of QUEST HD, QVC HD etc.. which TJT1 was curious about. My initial feelings was that the Tuner in my Panasonic was the cause as the TV signal goes through this before it hits the TV but confused now...
There is nothing to be gained by retuning. Leave as is.

Signal level is too high at 100. 70% is a rough ideal to aim for.
Whether that accounts for the problem or not you should try to address that first by getting an attenuator. Variable attenuators are usually only a few pounds.

As both the TV and DVDR are affected it is unlikely to be a problem with the DVDR - but it is still a possibility.

Try taking the aerial direct to the TV temporarily and see what reception results you get.
 

Sony65

Active Member
Actually I think the Aerial man fitted what looks like an Attenuator as he said my Signal Level/Signal was too high but I still have problems. I checked the Signal Level and it is 100% for HD channels and the same for SD channels. The Signal Quality on SD channels is also 100% but fluctuates badly on HD channels depending on time of day etc.. I will try plugging the aerial directly into the TV and see whether that helps. Will let you know the outcome thanks for all your help so far......
 

TJT1

Member
The signal quality WILL vary wildly f the signal strength is too high. It is likely overloading the tuner which causes total picture break up. Get a 20db variable attenuator (Amazon or eBay) and reduce the signal strength to less than 100.
As a matter of interest, what is the sig strength on your TV?
 

Sony65

Active Member
Well actually the Signal Level is 100% on the HD TV channels but it's the Signal Quality that is fluctuating. This all started off with my Panasonic Recorder loosing HD channels but then the TV started experiencing the same problem. At the moment my Recorder shows a few of the main HD channels but not all eg. QUEST HD, QVC HD aren't showing in the guide and when I select say BBC 1 HD is says No Signal. As for an attenuator as I said previously it seems that the aerial guy fitted one of these to the end of my aerial cable which has 6 printed around the edge. This is strange as I have had the same TV/Recorder set up for over 2 years without any problems and I haven't touched anything but around 2 weeks ago the HD problems started. But from recent experience they are problematic at start/end of day for my TV but my Recorder is problematic all the time. I initially thought it was the Recorder's Tuner could this still be the cause?
 

TJT1

Member
Unlikely. Signal level is still the main suspect IMHO. They have been screwing around with the channels and Multiplexes recently, and it depends on your transmitter which could also be Bluebell hill.
I know that you said the aerial guy fitted an attenuator, and from what you say, it seems that it is a 6dB one. I am suggesting that you get a 20dB variable one so that you can get the sig strength off the 100% to see if it is that that's causing your problem. Something like THIS should do the trick or one like THIS if you have F type plugs/sockets.
 
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Sony65

Active Member
Thanks for your continued assistance on this. Do you think the fact that my Recorder is having problems with ALL HD channels and my TV just with some at certain times of day could be the same problem of Signal Level which is 100% for both TV and Recorder as it appears strange as I would have thought both TV and Recorder would have the identical HD channel issue? I believe I use the Crystal Palace transmitter which assume is different to Bluebell Hill?
 

A1944

Active Member
Yes, Crystal Palace and Bluebell Hill are very different. CP is in SE London and BH is between the Medway Towns and Maidstone.
 

TJT1

Member
Do you think the fact that my Recorder is having problems with ALL HD channels and my TV just with some at certain times of day could be the same problem of Signal Level which is 100% for both TV and Recorder as it appears strange as I would have thought both TV and Recorder would have the identical HD channel issue?
Possibly and probably, and there is only one way to find out (documented above, unless you 'get a man in'.
I believe I use the Crystal Palace transmitter which assume is different to Bluebell Hill?
Please tell us why you think you are on Xtal Palace. It's generally no use guessing as it makes a lot of difference if you have to do a manual tune. Clue: Bluebell hill is ITV Meridian, Xtal Palace is ITV London.
The main thing to remember is that when/if you have successfully tuned in all the channels, DO NOT RETUNE when/if you lose them again. It will achieve nothing other than to delete them from your tuning database. It will then definitely need yet another retune at an opportune time to get them back.
 

Sony65

Active Member
I checked out the Freeview Checker for my postcode etc.. and it says that the Predicted Transmitter is Crystal Palace.
 

TJT1

Member
But that does not tell you which one you are actually receiving.
 

Sony65

Active Member
I have now checked the BBC Transmitter Check service and Crystal Palace is the nearest one to me and probably the one I am receiving from. It shows that I should receive a good signal for all HD channels. At the moment my TV is receiving all HD channels but my Recorder doesn't have any at all just SD channels. Against all advice I did a unplugged/plugged aerial retune on my recorder and it didn't pick up any HD channels and CH 30 shows 100% Signal Level and 0% Signal Quality. So I am back to square one with the Recorder being the possible cause?
 
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TJT1

Member
You just keep saying the same thing.
The most likely 'possible cause' is that your signal is too big. 100% sig strength and 0% quality is a sure fire indication that the signal is too big. Get a variable 20dB attenuator and prove me wrong.
The reason that it's your Recorder that's playing up is that the Recorder probably has a more sensitive tuner.
Find out what transmitter you are receiving from. I suggested a way in post #17.
Oh, OK, I give in. :eek:
 

Sony65

Active Member
OK. Before your head and heart explode all I was hoping for was that someone would say that even though my TV/Recorder set has been perfect for over 2 years the tuner in the Recorder can become more sensitive over time and therefore cause this type of problem. So contrary to what has been said by some before my Recorders sensitivity is the likely cause brought on by too strong Signal Quality which hasn't changed over the years but now is causing problems. Don't bother responding because I guess I already know the answer.......
 

Gavtech

Administrator
Please be careful about mixing up signal quality with signal strength.
You cannot solve problems with hope. It can only be done with systematic analysis and appropriate action.

If signal strength goes over 100% then signal quality will get wiped out.

I don't know why you wish to cling to your theory regarding tuner sensitivities.

It is a (very small) possibility that there is something amiss with your DVDR - but you need to realise that broadcast circumstances are changing all the time and are subject to other variables too... and that you have a clearly defined known problem: that of a saturated tuner.
Your signal strength is too high and it requires a remedy.

There is no point in pursuing any other remedy or line of pursuit until you deal with that problem first.... and it the most likely explanation for the entire problem.

Additionally you will now have to retune once again at some time when the signal can be relied upon.

Get an attenuator.
 

TJT1

Member
And that's from someone different! (again) :rotfl: :clap:
 

Sony65

Active Member
OK. Have now purchased a 0-20db Attenuator and on full minus setting it reduces the Signal Level from 100 down to around 91 on my TV, and the SQ fluctuates between 20-67% depending on time of day. What doesn't help is that With or Without the attenuator the SQ gives the same readings. I still have the same problem with the HD channels on my PVR even though the SL has reduced from 100 to around 80 but the SQ is very hit and miss and I sometimes have around 20% quality but depending on time of day often it is 0% which is exactly where I was in the beginning. Not sure what SQ should actually be on my PVR but 20% does give me HD channels. I have tried plugging the aerial directly into the TV and the SQ remains unchanged in line with above percentages again With or Without an attenuator. So to summarize... I am back to square. I would prefer comments from those who think they can help and not silly quips and dancing balls trying to be funny. Much appreciated.
 
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