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All posts by Ian Robinson

Below are all of Ian Robinson's postings, with the most recent are at the bottom of the page.

Single frequency interference | Freeview Interference
Monday 7 May 2012 9:47PM
High Wycombe

I seem to only be able to receive BBCB, SDN signals & intermittently D3+4 on my Samsung smart TV in the lounge. All other signals are pixelated. I live at HP10 9NN. The transmitter I select is Crystal palace. I live in a flat with a communal aerial. The TV & radio signals come down a single co-ax into the double socket (that splits TV & radio signals) in the lounge & a second co-ax goes out from the sockets to another flat. from the socket there is a splitter/booster that sends one signal to the TV in the lounge & one to the bedroom. The Warfdale TV in the bedroom can show all channels perfectly from the same feed. I have swapped the cables & removed the splitter, the outcome is the same. The signal checker on the Samsung TV shows the signal is strong but the bit rate error level is fluctuating. I suspect the Samsung is more sensitive than the Warfdale. Any advice you can give would be greatly appreciated.

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Thank you jb38, i need to just clarify a few points. The splitter/booster is what i have added to split the TV signal, coming from the socket, to the respective rooms. The Warfdale is the furthest from the socket. The original set up behind the socket is one co-ax in, carrying the TV & radio signals & one out. I presume this is to another flat as the co-ax cables are connected together via the back of the socket. The two co-ax come in opposite each other, with the centre cables going to the same screw & the outer braiding have a clip each. The socket filters seperate the TV & radio signals into their respective sockets (TV out & Radio out). I have tried fitting a new single socket; a double socket; i have swapped the feeds to the different rooms; i have run the cable direct to the Samsung (without & without the splitter/booster). the result is always the same, the Samsung struggles & the Warfdale works. At the end of the auto retune on the Samsung i have to select secondary region (London or Southern). The channels affected differ between the region selected. Whichever region i select, i get pixelated channels, even if the channels affected differ. I will check the mux number & if they differ, does that mean i have to manually tune to the better signal? Also could i manually tune to receive one channel from London & another from Southern, depending which is best? If the cable set up at the socket does supply other flats, could one or all of them be causing the problem, by either having interfering equiptment connected or just too many TV's being watched at one time? The pixelation is worse at peak times.

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Ian Robinson: jb38,
My Samsung model is UE32D6530.
when i go into manual tuning, it shows the signals from both the Meridian & Crystal Palace transmitters (see below).

Channel Frequency Bandwidth
23 490000Khz 8MHz Rescan
42 642000KHz 8MHz Rescan
25 506000KHz 8MHz Rescan
22 482000KHz 8MHz Rescan
28 530000KHz 8MHz Rescan
30 546000KHz 8MHz Rescan
45 666000KHz 8MHz Rescan
61 794000KHz 8MHz Rescan
26 514000KHz 8MHz Rescan

However in the programme guide list there are not, for instance, two BBC1's, one from each region. Otherwise i could just select the strongest signal BBC1 at any given time.
I only had time last night to check BBC1 on the Warfdale & that was from Crystal Palace. If i remember rightly, the last time i did an auto tune on the Warfdale, all the channels showed from Crystal Palace.
I don't know if it is relevant, but the Wooburn repeater is dead in line between my flat & crystal Palace?

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jb38, I checked both TV's last night (details below).


Multiplex BBC1 ITV1 ITV3 Dave Yesterday
Channel 23 26 25 22 28
Signal strength Medium Very Good Very Good Good Very Good


Multiplex BBC1 ITV1 ITV3 Dave Yesterday
Channel 23 26 25 22 28
TSID 1044 2005 3006 5040 6040
ONID 2339 2339 2339 2339 2339
Region London London London London London
Signal 100 100 100 100 100
Khz 490000 514000 506000 482000 530000
Bit error 43 2000 1751 2000 2000
Service ID 1044 2045 3eb0 5700 64c

I deleted all channels on the Samsung & manually tuned to only the Crystal Palace signals.
BBC1 seemed better, but if you look at the bit error at the time of test this will explain why. I have noticed that when BBC1 shows well ITV1 doesn't & vice versa. The bit error fluctuates to varying degrees.

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