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Old 10-03-2016, 23:35
newda898
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So..my HDR 2000T, for some reason does not pick up any channels on channel 25.

Signal Strength is 77%, Signal Quality is 100%. Trying to manually tune yields no results as "No Channels found"

However, the TV, connected to the same aerial cable after it has been through the box...is perfectly able to pick up my missing channels on 25.

Any ideas?
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Old 11-03-2016, 00:22
Martin Liddle
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So..my HDR 2000T, for some reason does not pick up any channels on channel 25.

Signal Strength is 77%, Signal Quality is 100%. Trying to manually tune yields no results as "No Channels found"
Start off by telling us where in the country you are and what transmitter you are tuning to?
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Old 11-03-2016, 11:05
newda898
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Start off by telling us where in the country you are and what transmitter you are tuning to?
Southampton, and the Rowridge transmitter.
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Old 11-03-2016, 12:28
Martin Liddle
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Southampton, and the Rowridge transmitter.
Sorry in that case I don't have a good idea. There is a long standing problem reported by people receiving specifically from Hannington that the COM7 multiplex comes and goes with no discernible pattern and it is mainly Humax kit that is affected. I can only suggest a careful check of the aerial cabling for any badly made joints, badly fitted connectors or any evidence of water ingress. Also make sure the aerial cable is kept well away from the HDMI cable as this can cause selective interference.
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Old 11-03-2016, 12:42
chrisjr
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Southampton, and the Rowridge transmitter.
Where is the aerial? Is it outside in the fresh air or stuck in the loft? Lofts can be unfriendly places for aerials. There can be all manner of reflections floating about that make reception difficult in certain circumstances. And changing the amount or layout of stuff stored in there can alter things as well.

One oddity of Rowridge is that it transmits both Horizontal and Vertical polarisation at the same time. If you can get at the aerial it might be interesting to see what effect twisting it vertical has.
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Old 11-03-2016, 13:24
newda898
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Sorry in that case I don't have a good idea. There is a long standing problem reported by people receiving specifically from Hannington that the COM7 multiplex comes and goes with no discernible pattern and it is mainly Humax kit that is affected. I can only suggest a careful check of the aerial cabling for any badly made joints, badly fitted connectors or any evidence of water ingress. Also make sure the aerial cable is kept well away from the HDMI cable as this can cause selective interference.
Ah righto, I think saw that thread on the humax forum and thought it might yield the answer.

Will certainly try and sort the cabling out back to make sure the hdmi isn't nearby.

Where is the aerial? Is it outside in the fresh air or stuck in the loft? Lofts can be unfriendly places for aerials. There can be all manner of reflections floating about that make reception difficult in certain circumstances. And changing the amount or layout of stuff stored in there can alter things as well.

One oddity of Rowridge is that it transmits both Horizontal and Vertical polarisation at the same time. If you can get at the aerial it might be interesting to see what effect twisting it vertical has.
I'm in flats so it's somewhere up top so no idea. Might try and ask some neighbours too if I can get them to understand the question.
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Old 11-03-2016, 14:08
MartinPickering
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However, the TV, connected to the same aerial cable
Sometimes crappy or damaged cable will selectively filter out specific frequencies, dependent on its length and the input impedance of the equipment.

See http://www.satcure.co.uk/tech/kinked_cable.htm

(I'm not saying that this IS the cause - merely that it's a possibility that should not be overlooked.)
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Old 11-03-2016, 14:17
chrisjr
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Ah righto, I think saw that thread on the humax forum and thought it might yield the answer.

Will certainly try and sort the cabling out back to make sure the hdmi isn't nearby.



I'm in flats so it's somewhere up top so no idea. Might try and ask some neighbours too if I can get them to understand the question.
Instead of asking them whether they can receive "channel 25" and get a load of replies that yes they do get the new Home Freeview channel ask them if they get things like ITV3, Drama, 5USA, Quest etc. And if they can both view and record them (assuming they have a recorder).

The difference between a UHF Channel number and the numbers they press on the telly remote to view a programme is lost on the vast majority of people

I would be doubtful that you have a cabling error if the TV gets all the channels, especially if it is hooked up via the recorder. You would think that anything filtering out the mux before it hit the recorder would also filter it out from the TV as well. Unless it is attenuating the signal and the TV is better able to deal with weak signals.

You could check that by comparing the relative signal strengths of the three COM muxes to see if COM4 is significantly weaker.

When you do a manual tune does the recorder allow you to choose DVB T or DVB T2 modes? Just possible that for some strange reason it is thinking COM4 is DVB-T2 which wouldn't work very well. Mind you that phrase involving straws and clutching springs to mind
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Old 11-03-2016, 15:52
newda898
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Instead of asking them whether they can receive "channel 25" and get a load of replies that yes they do get the new Home Freeview channel ask them if they get things like ITV3, Drama, 5USA, Quest etc. And if they can both view and record them (assuming they have a recorder).

The difference between a UHF Channel number and the numbers they press on the telly remote to view a programme is lost on the vast majority of people

I would be doubtful that you have a cabling error if the TV gets all the channels, especially if it is hooked up via the recorder. You would think that anything filtering out the mux before it hit the recorder would also filter it out from the TV as well. Unless it is attenuating the signal and the TV is better able to deal with weak signals.

You could check that by comparing the relative signal strengths of the three COM muxes to see if COM4 is significantly weaker.

When you do a manual tune does the recorder allow you to choose DVB T or DVB T2 modes? Just possible that for some strange reason it is thinking COM4 is DVB-T2 which wouldn't work very well. Mind you that phrase involving straws and clutching springs to mind
Well the TV thing is the bit that gets me, hence why I think it's a humax issue. Yes, will certainly try the DVD-T2 thing. Might actually disconnect the TV too and see if that makes a difference.

Maybe also wait until we get some high pressure see if that helps.
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Old 11-03-2016, 16:10
newda898
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Ah, think I may have solved it!

Tidying up in the cupboard, swapping cables and trying different lengths.
During the process I moved the power brick for my NAS drive to the bottom shelf.

And as if by magic, the shopkeeper appeared!
So there we go, interference from a transformer brick. Thanks for the pointers!
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