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Thursday, 7 June 2012
9:55 PM

jb38: Loop under construction but I have done some back to back testing. I was getting problem on PVR but in bedroom a indoor Yagi, spare digibox and 9" monitor video was good. I then connect PVR to yagi. and moved digibox + monitor and connected to 'suspect' aerial in living room. My hope was that I would get a workaround by using a 'remote' aerial but this afternoon during rain, PVR was having problem yet monior was error free. Therefore it appears up-scalling via HDMI is now an issue post DSO and PVR records up-scalled version to hard drive.

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Robert's 20 posts GB flag
Friday, 8 June 2012

4:58 PM

Robert: What model of PVR are you using? but with regards to your suspicion about a possible post DSO issue having cropped up connected with the HDMI cable link, have you actually verified this as applying or not? obviously done by just temporarily coupling the two devices together via a scart lead, although it does have to be said that the superior HF characteristics of HDMI make it more vulnerable to being interfered with, so the cables used should be as short as possible as well as being of reasonable quality, this of course excluding cables seen with fanciful claims being made for them as well as being sold at inflated prices.

Another point I meant mention before concerning you having stated that your reception gets worse when it rains, a possible reason for this could be caused by the combination of the height of the mast in relation to your proximity to it, insomuch that the signal level received could be even more intense by the moisture in the air conducting the energy from the masts radiators more efficiently than if would be directly through air, this having the effect of making you appear as being even closer to the mast than you are, as indeed just like happens in any circuit where high voltages exist irrespective of whether it be 50Hz or 500Mhz.

A somewhat crude way to tell if this is happening is to place a metal rod on your window ledge and connect one end of a FET (high impedance) input voltmeter on to it, the other meter lead not being connected to anything unless the reading is very low, then clip it onto another piece of metal.
By the way older analogue pointer types are generally better for tests of this sort.

The test being, that provided the meter doesn't have any RF blocking measures in it like a capacitor having been placed across its input terminals then note the reading obtained in dry weather, then compare this to the indication seen when it rains, even better if the rain is on the rod.

Of course this "closer effect" when it rains referred to can completely reverse over long distances, where a signal can in many cases be reduced rather than enhanced for a variety of reasons.

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jb38's 7,179 posts GB flag
Sunday, 10 June 2012
12:13 PM

jb38: Thank you for your invalueable help but Sorry you are getting too focused on my equipment.I used indoor aerials but I have data from 3 three seperate communial aerial systems. All that appear to suffer in same way and conformation that this is new problem, linked to DSO and when it rains.

Everyone I've talked too in my block (who uses CP) has seen intermittent reception problems. That is seven households. Two people in two different blocks to mine have a 'carbon copy' of my problem.

Arqiva made a large number of changes all at the same time any one of which could have introduced an intermittent problem. Each one increases the technical risk of the project which I think were huge the more I read, the more I would panic.

Even if I was sucessful following your advice, digital TV in this area could only be described as unbelievably flaky.

I've got a meeting on Monday which might put this one on a professional footing.

My PVR is a Panasonic DMR-BW780 but My TV Samsung LE40C530F1N agrees even if it does not get so upset at the bad RF it decodes fom its own aerial. The remote aerial test are inconclusive at the moment.

I recorded 700 hrs of perfect video between Oct 2011 when PVR/Aerial configuration was setup and 3 April 2012.

I begining to think there are two different intermittent problems. I need to 'white box' a digital tuner, I can only black box test at the moment.

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Robert's 20 posts GB flag
12:50 PM

Stephen P: It could be it is doing an automatic standby but why now? Have a look around the menus see if it has such a feature and if that could be the cause. Bad PSUs are a fact of life because everything built to a price, lots devices share the same electronic units inside, like power supplies. Is it getting hot and needs better ventilation? might have thermal shutdown built in.

Your best way forward is to google the Wharfdale model number and see if you pick up on a discussion thread. Treat the information it witn a bit of caution an expert can be caught out because of a querk in design of that model may invidates he general 'good' advice.

Google the problem, prehaps try with 'Wharfdale' added

If you can discover a 'firmware revision' google just that code. See what you get.

If you nifty with a screew driver and careful with mains electricity, have a look inside and see if you can find any code numbers and google them.

This is all about detective work and tapping into people who know more (maybe)or can show a path to solution.

It all about how many hits come back to any interenet search, too many or too few and relevance to the problem.

Use the internet and read with caution.

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Robert's 20 posts GB flag

8:36 PM

Robert: My comments were purely based on you having stated (7th @ 9.55pm) that it now appears that up-scaling via HDMI is now an issue post DSO, and also you having referred to reception deteriorating when it rains with of course me having explained a possible reason for this occurring.

That said though, the reason I explained would affect a communal aerial system much more than an indoor one by the fact that the communal aerial will also capture the high level of EMF that's in the rain by having direct contact with it, whereas you wont with an indoor aerial and why I mentioned the rod on window ledge test as being the only way to verify this.

So when you say that you now think that there are two different intermittent problems, yes! I feel that as well, but in my opinion one concerns the communal aerial system, and the possibility that its distribution amplifier "inputs" are being overloaded by an excessively high level of signal and is causing slight instability in the amplification / distribution system, and with this being reflected in the quality of the signal from the other end that's being fed to the various apartments.

The second being that your indoor aerial is suffering from an element of capacitive type problems, i.e: movements from within the room or from an adjacent apartment, the only way to eliminate (or near anyway!) this being to have the aerial placed as near to the window as you can.

I honestly do feel that you are looking (or maybe hoping?) for some highly technical reason for your problems that possibly involve the construction of the radiating elements on the mast, whereas the real reason is far simpler, that of being located in area where a permanently high level of RF is circulating around it from all angles.

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jb38's 7,179 posts GB flag
Stephen P

8:50 PM

Robert - thanks.

Now where was it put when we tidied?

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Stephen P's 1,173 posts GB flag
Monday, 11 June 2012
Wullie B
10:17 AM

I cant get any the BBC channels on my freeview box
I used to get all the channels but now I get every channel except the BBC one's.

Any ideas how to solve this problem?

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Wullie B's 1 post GB flag
Wullie's: mapW's Freeview map terrainW's terrain plot wavesW's frequency data W's Freeview Detailed Coverage
Tuesday, 12 June 2012
12:15 PM

JB38: I should avoid writing aloud what I thinking. The TV tuner does better against the interference than the PVR and most of the time agrees that the RF is crap. However the PVR always produces a better quality of picture (when the system works) in the same way as switching on the 5.1 gives better sound.

It was raining when I finished the loop aerial & connected it up to a 9 portable TV placed to I can see it and main TV at the same time. Although the 9 reported steady green for signal quality (80%) and signal strength (80%) on the Mux, the picture was splattered with error pixels. So was it on the PVR, now only connected to TV only via SCART. So was it was on the main TV, as it was on a spare Digi box on AV input to 9. Four independent indoor aerials/tuners all said the RF was rubbish at that time.

The weather has not cleared so nothing works (error free) at the moment.

Watching the same program comparing two sources at the time I was bugged by a lack of synchronicity of the pixel error patterns until this morning, when I discovered why, the internal tuner of the 9 TV is the fastest, the TV sound echoes behind and the PVR video lags. The Digi box and TV seam in sync and the PVR sentence lags the Digi box. So Im getting time dilation.

Generally the interference was worse on the loop, then PVR, difficult to judge between main TV and Digi box because of the difference in screen size.

A retune of 9 TV on the loop discovered 3 of the 5 muxes. Mux signal quality/strength look reasonable across the board and are all Green. I think retuning is too error sensitive and lacks robustness.

I will wait for good weather, restore the tuning in 9 and go hunt for a good picture with loop position. When I get all Muxes found on a retune with the loop, I will consider connection to PVR.

What you be your suggested action plan?

I have noticed weird thing happening to the station number allocation by just switching aerials and I can see typical engineering folklore growing, Disconnect aerial, retune, reconnect and retune again. Does anyone have a handle on what might be going on? I dont think it is important to this problem, just curious

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Robert's 20 posts GB flag
Friday, 22 June 2012
5:54 PM

Why can I not get Channel 10 when it rains here in Ely Cambridgeshire area. I get a lot of pixellation as well . Any solutions please?

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Hodgson's 1 post GB flag
Dave Lindsay

6:42 PM

Hodgson: In your general area, signals can be received from a number of different transmitters. The first thing is to check that your receiver is tuned to the transmitter to which the aerial faces. To do this, bring up the signal strength screen and whilst on ITV3.

Here are the UHF channel numbers (equivalent to frequency) of the following transmitters:

- Tacolneston C42
- Waltham C29
- Sudbury C49
- Belmont C30
- Sandy Heath C51

If you don't know which transmitter your aerial is directed at, then let us know its rough direction and the UHF channel number that ITV3 is tuned to.

For some transmitters, a new aerial may be necessary, so knowing which transmitter you are using will allow advice as to whether this "may" be necessary.

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Dave Lindsay's 5,724 posts GB flag
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