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All posts by alexp78

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Multiplex names, frequencies and power level highlighting
Thursday 19 January 2012 11:23PM

Can I pick someone's brain?
I am at NG69GJ pointing to Nottingham.
After a couple of dropouts on HD I looked at the signal indication on my two month old Samsung. Only C21 indicated signal strength 98% but bit error rate of 800 (half the bar is in the red). Other muxes indicated zero errors. Other than the two dropouts there has not been any problem with reception on C21. I thought maybe there was a transmitter fault that needed fixing but now several days later the bit errors are still about 800 just for C21. I tried turning off external boxes (PVR, DVD) and connecting the aerial direct to the TV, no splitter, ensuring well away from other cables e.g. HDMI. The aerial is wideband fitted a few years ago, and proper digital cable - no amp. Same result. I looked here for a frequency map of other use of C21 but the nearest in line of sight is 80 miles away in Wales. The only thing I can think of is another frequency close to 474 MHz being picked up by the aerial in line of sight. Any ideas?

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Thanks Briantist, I've looked at all that.

77 stations stored. Each frequency checks out as MUX ONID 233a and NETWORK EastMidlands ID3023. There is only one channel in the 800+ range which is BigDeal as 829 (690MHz), and the old channel as 32 (722MHz) displays that it's old and needs retuning. The new channel is on the same NETWORK as above.

Signal strength:
I am 3 miles from Nottingham Kimberley, but the signal received is comparable to that from the more powerful Sutton Coldfield 40 miles away. The wideband aerial is not high-gain, and there is no booster. I tested with all other equipment disconnected from mains power and also disconnected from the TV and from the aerial. I have a number of aerial Y-splitters (4 inductive and 2 resistive), so applied various attenuations by chaining these. Results:
Number of splitters / Signal Strength / Bit Errors:
0 / 98 / 800 (approx)
4 / 70 / 800
6 / 35 / 1200

To recap: the problem is that only one frequency (474MHz) reports these errors on all four channels (which are the High-Definition stations). All other channels show Signal 100 and Bit Errors zero.

Can you think of any other factor causing this (outside of faulty internal decoding in the TV)?

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