Loss of HD channels

W

Walshy

New Member
Hi, I've recently lost BBC One HD and all other channels on that same Mux. The other HD channels, BBC Four HD etc, are ok and BBC One HD etc are ok on my TV ( a 2012 Panasonic).
This has only happened recently and I noticed that the @FreeviewAdvice twitter feed suggested that bad weather might affect reception.

I retuned over the previous weekend and it didn't even find them, retuned again last weekend hoping the weather had improved, and it did find them, but the picture either breaks up or I just get the 'scrambled' message.

I've got a feeling it's down to a neighbour's huge silver birch getting a bit more leafy. Any suggestions on how to fix this or boost my signal, other than a copper nail?
 
Retuning in response to apparently losing services is a very bad idea, unless the loss is known to be due to scheduled alterations at the transmitter. All you succeed in doing is to ensure the services in question cannot be picked up when conditions improve unless you retune again when they have (got a crystal ball?). Did you do a complete automatic retune, or a selective manual one? If the latter, did you remember to set DVB-T2 when tuning the BBC B mux?

If you did the former (ie an automatic retune), you might get lucky by doing a manual retune (all muxes, or at least the missing muxes) using this procedure (as linked from Things Every... section 2):

MartinLiddle said:
  1. Go to [URLhttps://www.freeview.co.uk/corporate/platform-management[/URL] scroll down to the "Check Freeview at my home" section and input your postcode and house number. When the initial results appear, scroll down past the available channel icons and you should find a "Detailed view" button. Click it to get the results that are useful for tuning purposes. Look carefully at the information returned for each transmitter; don't blindly accept the recommendation for the most likely transmitter. You are looking for the single transmitter that will give you the best signal strength across the range of multiplexes you wish to receive.

  2. Having decided on a transmitter,note down the channel numbers for the mutiplexes typically between six and nine (shown in the white column headed N (the N is white on a black circular background)) ).

  3. On the HDR press Menu>Settings>Installation. You will be prompted for a password which defaults to 0000.

  4. Select Automatic search for channels and immediately stop it; save the results. This deletes all previously found channels.

  5. Select Manual search. In the Channel field press right arrow, scroll up or down and select the first channel number from your list. In the Transmission field leave it on the default DVB-T for all channels except the HD channels; for the HD channels it must be changed to DVB-T2. Press Search. This should find a number of channel names. Save the results.

  6. Repeat the manual search for each channel previously noted.

  7. You will then need to enter your schedule of recordings.
Click to expand...
Footnotes:
  1. The resource indicated in step 1 is now linked directly from the forum index page: Freeview - Coverage Checker.

  2. No need to re-enter your schedule if using Custom Firmware - just go to WebIF >> Scheduled Events >> Backup/Restore (the schedule is backed up daily, automatically).

Walshy said:
I've got a feeling it's down to a neighbour's huge silver birch getting a bit more leafy.
Click to expand...
I don't see why you would lose BBC B (a high-power mux) and not COM7 (a low-power mux), unless your aerial setup is extremely marginal (possibly as a result of the frequency shifts). What transmitter are you on? What is the status of StDef services?

You might find some answers here: https://hummy.tv/forum/threads/refe...nel-numbers-aerial-groups-how-to-choose.9224/
 
Sorry to reopen this thread. I've lost BBC B again. Com 7 is still fine, as are all the SD channels.
My 2012 Panasonic TV can receive BBC B fine with no interference or drop out and shows signal strength and quality is good. Its aerial input is fed from the output of the Humax. This makes believe my 15 year old aerial is fine, but I don't know enough about this sort of thing. I'm guessing I'll be able to get BBC B again once this weather clears, but does that mean I need a new aerial?
Thanks for any help
 
Walshy said:
Sorry to reopen this thread
Click to expand...
Why? It's the right place if the conversation needs to continue.

What changed previously – did the problem just go away? You really haven't provided much in the way of data to even attempt a diagnosis.

Go to Menu >> Settings >> System >> Signal Detection. For each channel listed (press 'OK' or right cursor, then select the next channel in the list) observe the Strength and Quality gauges for half a minute and report the worst-case figures for each channel.

If you are able to find a way to do the same with the TV, report those figures too.
 
Walshy said:
Hi, I've recently lost BBC One HD and all other channels on that same Mux. The other HD channels, BBC Four HD etc, are ok and BBC One HD etc are ok on my TV ( a 2012 Panasonic).
This has only happened recently and I noticed that the @FreeviewAdvice twitter feed suggested that bad weather might affect reception.

I retuned over the previous weekend and it didn't even find them, retuned again last weekend hoping the weather had improved, and it did find them, but the picture either breaks up or I just get the 'scrambled' message.

I've got a feeling it's down to a neighbour's huge silver birch getting a bit more leafy. Any suggestions on how to fix this or boost my signal, other than a copper nail?
Click to expand...
Are these the same symptoms that you had a few years ago?

Problems receiving all the bbcb mux

Having read posts on problems with HD channels since the new channels became available, I haven't seen any mention of the problem I keep getting. After retuning all was working fine, but then recently, maybe two or three weeks ago, all channels on the bbcb mux (BBC1, 2, 3 itv and ch4 hd) started...
hummy.tv hummy.tv
 
Well spotted (2014). As a reminder:
Ezra Pound said:
It's a long shot, but it might be worth moving HDMI and aerial cables about (more specifically, away from each other) as it is just possible that the high frequency signal being carried by the HDMI cable could be interfering with the single RF frequency that carries C40+ 626.2MHz
Click to expand...
Walshy said:
Thanks Ezra, I'd not considered that, but had moved my stuff around a bit recently. Looks like it could well be the DVD player causing interference.
I've got the channels back now, so will just see how things go. Thanks again for you help.
Click to expand...

So basically we're talking about a recurring problem (Jan 2014, Apr 2021, Aug 2021) with (presumably) long periods of harmony in between. This is almost certainly a local problem, perhaps corresponding with when cables get disturbed.
 
After com 8 was killed off we had so much trouble with com 7 reception (picture break up, failed recordings) that I abandoned it and now use the SD channel for BBC 4, which is really the only one on com 7 that we used. (With the recent change of focus for BBC 4 to being a repeats channel this now seems prescient.)

The strength was fine and the problems persisted through winter, so I suspect it may have been interference from other com 7 transmitters, because of the single-frequency network.

(A few weeks ago I removed the additional aerial I fitted for Ch 55&56 to reduce the wind loading in view of predicted stronger storms in future, so don't ask me to do any tests please :rolleyes: )
 
Well that's highly embarrassing. DVD player now removed and everything fine again. Answer to my problem in my own posts, albeit from a few years ago.
Adding in a Nintendo Switch at Christmas must have rejiggled the cables enough to make it borderline. Then bad weather knocks the reception enough that I can't receive that mux.

Thanks for the help guys. I'll try not to ask any more questions about receiving HD channels again, at least without reading what I've posted before
 
Walshy said:
Thanks for the help guys. I'll try not to ask any more questions about receiving HD channels again, at least without reading what I've posted before
Click to expand...
Don't worry about it – I'm sure we all suffer memory glitches from time to time.
 
It strikes me that either the DVD player is faulty (EMC non-compliant), or the aerial leads are that nasty thin stuff with plastic moulded plugs! Decent screened HDMI cables might help too... but if the DVD player kills it even when not actively displaying (and it wouldn't be actively displaying if you're monitoring the HDR), it's firmly in the frame.
 
I agree. I can't remember the last time I used it anyway, so it will remain unplugged for the foreseeable. I think the aerial leads are ok in that they were provided by the bloke who installed the aerial. He made them up from a big roll of cable.
My guess is cheap HDMI for the DVD player or the player itself.
I'll wait for the next spell of bad weather (can't be far away) and see if everything is still ok.
 
Walshy said:
a big roll of cable
Click to expand...
Hmm, if it was traditional "low loss" then it leaks like a sieve through the screen, potentialy confusing for digital reception. If it was CT100 or "Satellite cable" with the foil 100% screen then it will be OK.
I assume the aerial includes a BalUn for a correct match to the coax?

I was a involved with some of the early tests on DVB-T as a guinea-pig viewer with reception problems in a fringe area for CP. Significantly the new "wideband" aerial also had a nice new long down-lead, both from the usual local suppliers. We experimented with diversity etc (ie more than one aerial), but eventually found that replacing my new installation with the CT100 and an aerial (eg a Triax) incorporating a proper BalUn removed all of the weird reception problems.
The conclusion based on mine and number of other fringe sites was that given a BalUn at the aerial and CT100 cable the viewers only needed to contend with the usuals - poor group coverage, poor aim and not enough signal.
 
Unfortunately CT100 has been obsolete for years, you can't buy it any more. Sad because it was great cable. There are allegedly more modern equivalents, but the last cable I bought was CT100 and I've only recently used the last of the reel so I can't say anything about the new stuff.
 
Walshy said:
I'll wait for the next spell of bad weather (can't be far away) and see if everything is still ok.
Click to expand...

my setup seems to do this when high pressure is around. I found one interfering culprit about a year ago but that is not plugged in anymore. And HP just hit again, lost bbchc mux.
 
sine24 said:
my setup seems to do this when high pressure is around. I found one interfering culprit about a year ago but that is not plugged in anymore. And HP just hit again, lost bbchc mux.
Click to expand...

It can be a distant transmitter (sometimes not even in the UK) using the same UHF channel which interferes more in high pressure conditions. At my previous job one of the RF engineers as a hobby was into seeing what could be received from how far away in various atmospheric conditions. He was a strange chap, brilliant engineer but strange.
 
Well, I now found out thatplugging in just an ordinary flat aerial worked whilst my roof aerial was not. I know the aerial is good and spot on orientated so could it be the cable from the wall to the t2?
 
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