Intermittent freeview problem any ideas as I'm stumped
Discussion
The system in question is at my friends house, I have tried everything I know and cant find the problem so thought maybe someone on here could give me an idea.
Since December both TVs ( after being on for 10-15 minutes especially on BBC channels ) freeze then break up and stay like this for a minute then work, then the cycle continues.
The original system with a new high gain aerial came down to the bedroom were a internal 2 way booster was fitted feeding that bed room and then a return feed to the lounge. After testing the signal a masthead was fitted up at the aerial and 2 way booster was removed, signal strength and quality improved greatly but the problem continues.
The problem is still there if the aerial is connected to just one TV or both, all cables and connections are fine and there are no obvious changes to the local environment.
The only thing i can thing off is 100m away is a 4 storey building that the aerial points through and maybe an apartment within this has changed something and this has then had an effect on the signal reception?
anyone got any ideas would be greatly appreciated
Since December both TVs ( after being on for 10-15 minutes especially on BBC channels ) freeze then break up and stay like this for a minute then work, then the cycle continues.
The original system with a new high gain aerial came down to the bedroom were a internal 2 way booster was fitted feeding that bed room and then a return feed to the lounge. After testing the signal a masthead was fitted up at the aerial and 2 way booster was removed, signal strength and quality improved greatly but the problem continues.
The problem is still there if the aerial is connected to just one TV or both, all cables and connections are fine and there are no obvious changes to the local environment.
The only thing i can thing off is 100m away is a 4 storey building that the aerial points through and maybe an apartment within this has changed something and this has then had an effect on the signal reception?
anyone got any ideas would be greatly appreciated
I'm not that experienced with the domestic end of TV RF signals but a few things spring to mind:
How far away is the Transmitter tower? Do you know? Your new high gain antenna might have too much gain and be overloading the receivers in the TV's. I suspect it's not the case, unless you're quite close to the transmitter.
Does the problem occur on both TV's simultaneously? On any channel, or just on certain ones?
Is it fairly consistent, in that it's every 10 to 15 minutes without fail, at any time of the day?
Things to look at:
If the problem's occurring simultaneously on both TV's, it suggests the problem's either affecting the signal before it reaches your antenna, or it's getting in on the cable(s) from the antenna to your receivers. Does the cable run past or close to anything electronic in the house?
From what I can gather (just by a quick Google), the Freeview frequencies are around the 474Mhz range. It's possible that someone nearby has some kind of communications equipment or radio transmitter (or something, maybe a Wifi booster that's creating noisy harmonics, I'm just thinking out loud here) that's interfering with the signal. Do you know if any of your immediate neighbours are being affected? If they are, then there's something local to you that's doing something it shouldn't be.
There's always the possibility that it's an atmospheric effect, there were some a few weeks ago that seemed to cause problems with terrestrial broadcasts.
Personally I don't know what a boiler would do to cause a problem with your received signal, all electronics for the consumer and commercial market are supposed to conform to RFI standards. However, something may be faulty. You could always try turning stuff off in the house, piece by piece, and seeing if the problem goes away.
How far away is the Transmitter tower? Do you know? Your new high gain antenna might have too much gain and be overloading the receivers in the TV's. I suspect it's not the case, unless you're quite close to the transmitter.
Does the problem occur on both TV's simultaneously? On any channel, or just on certain ones?
Is it fairly consistent, in that it's every 10 to 15 minutes without fail, at any time of the day?
Things to look at:
If the problem's occurring simultaneously on both TV's, it suggests the problem's either affecting the signal before it reaches your antenna, or it's getting in on the cable(s) from the antenna to your receivers. Does the cable run past or close to anything electronic in the house?
From what I can gather (just by a quick Google), the Freeview frequencies are around the 474Mhz range. It's possible that someone nearby has some kind of communications equipment or radio transmitter (or something, maybe a Wifi booster that's creating noisy harmonics, I'm just thinking out loud here) that's interfering with the signal. Do you know if any of your immediate neighbours are being affected? If they are, then there's something local to you that's doing something it shouldn't be.
There's always the possibility that it's an atmospheric effect, there were some a few weeks ago that seemed to cause problems with terrestrial broadcasts.
Personally I don't know what a boiler would do to cause a problem with your received signal, all electronics for the consumer and commercial market are supposed to conform to RFI standards. However, something may be faulty. You could always try turning stuff off in the house, piece by piece, and seeing if the problem goes away.
boilers switching on and off can cause a slight glitch with free view TVs or box's mainly depending on were the booster is wired in IE if its on the same ring main.
Signal strength from the aerial going into the new variable gain masthead is lowest of 46db and maximum of 50db gain set to lowest setting of 15db as between the masthead and power supply is a new 2 way dc pass splitter.
Yes the fault happens on both TVs but haven't checked to see if its the same time. I have got him to time the regularity of the interference and will see him on Wednesday to find the results.
The cable comes down the roof and into the lounge no more than 5m of ct100 cable and doesn't go anywhere near any electrical or satellite systems.
Signal strength from the aerial going into the new variable gain masthead is lowest of 46db and maximum of 50db gain set to lowest setting of 15db as between the masthead and power supply is a new 2 way dc pass splitter.
Yes the fault happens on both TVs but haven't checked to see if its the same time. I have got him to time the regularity of the interference and will see him on Wednesday to find the results.
The cable comes down the roof and into the lounge no more than 5m of ct100 cable and doesn't go anywhere near any electrical or satellite systems.
It sounds like interference from an external source.
Somewhere nearby (same house or very near neighbour) may have a radio emitting device which transmits regularly. It could be that the transmission 'deafens' the TV receiver of aerial amplifier and causes the signal to be lost.
Try to get hold of a wide band radio sniffer. If there is an interfering signal, then it may be faulty equipment and the user should correct the fault.
Somewhere nearby (same house or very near neighbour) may have a radio emitting device which transmits regularly. It could be that the transmission 'deafens' the TV receiver of aerial amplifier and causes the signal to be lost.
Try to get hold of a wide band radio sniffer. If there is an interfering signal, then it may be faulty equipment and the user should correct the fault.
Do you mean a Max of -46dB (minus, that is) and min of -50dB? An RX level of Plus 46dB sounds very high, I'd be expecting smoke and flames from any of my receivers at that kind of level, although admittedly, they aren't televisions. Having said that, I may have misunderstood what you're saying.
As per the other reply, my gut feeling too is that it's external interference, from a nearby source. I have a small hand-held spectrum analyser, although I'm not sure off hand if it goes low enough (works up to 4Ghz). Something like that with a directional antenna might help you figure out what's going on.
It might actually be worth getting the company that installed the aerial to come back and do a spot of analysis. Hopefully they won't charge (or won't charge too much).
As per the other reply, my gut feeling too is that it's external interference, from a nearby source. I have a small hand-held spectrum analyser, although I'm not sure off hand if it goes low enough (works up to 4Ghz). Something like that with a directional antenna might help you figure out what's going on.
It might actually be worth getting the company that installed the aerial to come back and do a spot of analysis. Hopefully they won't charge (or won't charge too much).
Went round today to have a look and see if we could fix the problem but no luck. Weird thing is after timing it the breakup happens ever 11-12 minutes and for 30 seconds, this has made me think that it is some kind of environmental interference from some ones house near by. It only breaks up on the BBC mux and is on the Malvern transmitter ( haven't checked yet to see what MHz frequency that is yet ) so something near by must be on a cycle transmitting or receiving a signal. Any idea if we cant find the source how to block the interference?? cable is ct100 copper shielded if that helps.
in the house they have a new British Gas smart meter that sends signals to the boiler, i did think it was this but placed the remote device in the back of the van and drove it 100m away but it still happened so counted that out, they don't have any other device in the house so have said to knock on the immediate neighbours doors to see what they got for christmas presents as this problem started right on Christmas
It might be worth turning off the boiler completely to see if it makes a difference, but it seems to me that it's something RF related, especially since it's only the BBC mux that's affected.
As we've discussed already, I suspect something is transmitting regularly, at a frequency close enough, and powerful enough to lift the noise floor to such a level that your receiver(s) can't properly decode the incoming signal.
I would suggest you might get a result out of fitting a Band Pass filter of some sort, like these guys sell (and Maplin do).
http://www.garex.co.uk/AKD/akd.htm
Depending on where the BBC mux is, in relation to the other TV frequencies, you'll need to either chop off the lower frequencies, the upper ones, or both.
There's also a bit of useful info here.
http://www.stevelarkins.freeuk.com/tv_interference...
As we've discussed already, I suspect something is transmitting regularly, at a frequency close enough, and powerful enough to lift the noise floor to such a level that your receiver(s) can't properly decode the incoming signal.
I would suggest you might get a result out of fitting a Band Pass filter of some sort, like these guys sell (and Maplin do).
http://www.garex.co.uk/AKD/akd.htm
Depending on where the BBC mux is, in relation to the other TV frequencies, you'll need to either chop off the lower frequencies, the upper ones, or both.
There's also a bit of useful info here.
http://www.stevelarkins.freeuk.com/tv_interference...
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