Loss of signal strength

Discussion in 'Freeview & YouView' started by Sprog, May 24, 2019.

  1. Sprog

    Sprog
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    I'm having an issue with signal strength. I really can't remember if it's always been like this. I don't think so otherwise I would've done something about it all that time ago!

    On certain TVs, I can't get programmes like BBC1.

    Please see the images I uploaded to give you an idea of my setup.

    When I plug the aerial directly into the tester it hits the third (70) light.
    When I plug the tester directly into the wall/floor socket, I get one light but just about flickers onto the second too.
    When plug the tester into the lead that goes into the TV, I get just one light.

    Is there a way of boosting the signal? Do I need to replace or buy anything? Is the setup wrong?

    Thanks very much and hope you can help
     

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  2. TJT1

    TJT1
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    Signal lever sounds a bit marginal and the loft mounted 4 way splitter loses about 6-8 dB per output.
    Unless you can get a bigger aerial up there or, better still, an outside aerial, replace the passive splitter with a distribution amplifier. HERE'S a selection from Amazon. but you will need mains in the loft for these.

    Or you could use one of THESE between the aerial and the splitter. The power for these is fed up one of the co axial cables from the TV end, so no mains required in the loft. The splitter must be a DC pass one though (Yours is OK).

    In the mean time, check all coax plugs for security and a whisker of the outer braiding touching the inner.
     
  3. Rodders53

    Rodders53
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    FIRST check the cables and connectors.
    Most faults are due to poorly made connections and / or damaged cables.
    Remake any suspect ones - especially check the 'fly lead' and the connection to the socket in the room.

    THEN: Use meter to check level at the outputs of the splitter in loft: and all the other outlets in the rooms. (You only report on one).

    Most TVs have signal strength/quality metering built in which will be more accurate than that SLX device (which is 'broadband' and not very accurate as a result). Pro DVB-T/T2 meters are many hundreds of pounds.
    Use the TV metering and report findings for all the multiplex frequencies at your location.

    Avoid amplification if at all possible. But if needed read this: Television Aerial Boosters / Amplifiers, Splitters, Diplexers & Triplexers
     
  4. Sprog

    Sprog
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    Thanks guys for your replies. Extremely helpful.
    I'll check the connections and see if I can improve any before I purchase any amplifiers etc.
    All four room sockets were reporting around one green light.
    In the meantime, please would you answer these questions:
    1. Would it be worth disconnecting one of them to improve signal strength for the rest? I don't think the third bedroom's socket will ever be used now.
    2. After I installed the wall/floor sockets, I think I read somewhere that the type of connector I used was poor. I've uploaded an example. If so, would it be worth changing it to a better one? Would a F to F connector be better for less interference? I've uploaded an example of that too.
    3. Is there a big difference in the quality of fly leads? Is it worth buying a roll to make my own or will any gain be negligible?
    Thanks again.
     

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  5. TJT1

    TJT1
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    1. No. It will make no difference.

    2. a. They are because they are un-screened. b. Yes. c. F types beat the hell out of Belling Lee (BL). Use F Types everywhere you can and just use an F Type to BL adaptor between the end of the flylead and the TV.

    3. There is usually quite a big difference in screening between 'el cheapo' fly leads and ones you make up yourself and thus much better interference suppression. Best to make up your own using high grade coax such as WF100 (or WF65 if you want thinner, short leads). Either way use F type plugs and F to BL at the TV but make sure that you get the correct plugs for the grade of coax used.
    Any 'gain' as such might be negligible, but you will be able to breath easy that interference from a 'leaky' HDMI lead will be far less likely.
     
  6. Rodders53

    Rodders53
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    A 2-way splitter in place of the 4-way would more than double the signal to the sets (2-way 4dB loss, 4-way 8dB). Disconnecting outlets will make no difference to the losses but could cause unwanted effects due to impedance mis-matching. (Very rare in practice.)

    The 'meter' has a scale of 50, 60, 70 and 80 dB ref 1uV (microvolt). Ideal levels at a receiver for DVB-T are between 45 and 65 dBuV. But I doubt the meter is in any way accurate.
    Worth doing a check of the aerial ->f-coupler-> each outlet in turn 'direct' to see what difference you get?

    The TV metering may be a good guide to the levels they see?

    Although you are not clear why you feel you are suffering from inadequate signal, this is a case where I'd probably recommend a low-ish gain amplifier to make up for the losses in the splitter and the cable/terminations (plugs/sockets). Ideally around 12dB? TJT1's linked has variable 10dB (min) to 25dB; caveat it's not a brand I know personally - but see About Us - S.A.C. Electronics . ATV aerials recommend the Proception range.

    Again, transmitter and location of reception is unknow; occasionally that can have an impact (e.g. if a frequency change has moved signal outwith the response curve of an older grouped aerial.)
     
  7. Sprog

    Sprog
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    Thanks again.

    I haven't gone into the loft yet but have done some testing in two bedrooms.

    In the first bedroom, I lifted the floor panel from the floor and pushed out the TV module. It seemed to have improved the signal a bit with 2 green lights on the tester, although can't leave it like that! When I test it with the fly lead connected, only one green light. However, the signal seems to have improved as it now picks up all the channels and there doesn't seem to be any pixilation. I also tested it with another fly lead but seems to be same strength.

    In the second bedroom, it's a different story. Again, I get 2 lights from the floor panel but with the fly lead it only just seems to make it to one green light depending on where my finger is and at what angle. I get pixilation on certain channels. I tried it with another fly lead, it improves with no pixilation but with one green light, although the cable is running above and over the bed without interference. Again, can't leave it like that either!

    I think I'll change those floor ports to coupling F connectors instead and see if it improves.

    I'm actually wondering if there's a lot of interference going on underneath these beds. They're actually electric TV beds so they have motors and I've got a couple network cables, cables for Chromecast and bedside lights.

    The fly leads for these beds are wired in along with HDMI and power cables.

    Is it possible they're teetering on the low spectrum of an adequate signal and that can dip when external factors such as the weather come into play?

    I'm think of getting one of those 4 port amplifiers to replace the passive splitter in the loft. It's tempting and I have power up there! Other than changing to F connectors, I'm fairly limited with what else to do.
     
  8. TJT1

    TJT1
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    Not a good idea to have HDMI leads and TV RF leads in close proximity especially if they are not well screened. It is a known cause of problems as the HDMI leads can radiate RF at or about the same frequency as the TV stuff.
    Sounds very much like that's exactly the case bud.
     
  9. Rodders53

    Rodders53
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    Hmmm....
    Sound like the cables have been crushed and/or bent too sharply. Such bends can cause unpredictable, frequency-selective issues.
    F-plug joiner modules will likely make that worse, as the plugs need even more space in the back box and then the cables need to bend! {A very deep back box will help.}
    ATV has a solution - but you may not like it: Satellite, Television, FM, DAB, Aerial, Coaxial Cable, Plugs, Sockets, Connectors & Leads as it leaves the join visible.

    You can get screened TV socket modules as well - but again the coax cable bending radius can be an issue. e.g. TV Coaxial Outlet Euro Module - Female - Screened - White


    The unscreened TV socket modules won't be helping with interference rejection - but this sounds more like a basic lack of signal level to me. (Not that you've reported any of the TV's signal metering numbers to confirm).

    You need to get into the loft to make basic measurements/bypass the passive 8dB signal reduction to prove all is well with the aerial direct to the various sets, one at a time.
    If the loft aerial signal is inadequate direct to the TVs then its a different ball game (new aerial, outside?).

    Location and transmitter also may matter.
     
  10. Sprog

    Sprog
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    Well, I bought this today based on certain reviews who seemed to have the same issue as me.
    I'm pleased to say the tester has lit up all the green lights now on all fly leads expect the one that was giving pixelation which didn't improve at all. It's floor box lit up all the green lights.

    Therefore, it looks like I had two issues, first being improving the signal and the other being a damaged cable.

    All in all, very happy!

    I need to get a replacement cable for the damaged one now. I know it's been said that I might be better off making my own, but one of the ends has to be a right angle. Any ideas?

    Thanks very much for all your advice again, I really appreciate this.
     
  11. TJT1

    TJT1
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    F type right angle adaptor? HERE'S {Click} an example.
    Check out others and eBay.
     
  12. Sprog

    Sprog
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    Ah no, sorry, I meant this.

    It's the quality I meant especially at 4 metres. I suppose at that price, it's worth a try.
    I'd rather pay 4 times the price if I knew it was going to be much better especially in terms of shielded.

    I should be able to run it separately from the other cables until it goes up into the end of the bed where it will be tightly joined with the rest of them. Mind you, even though the HDMI cables are connected, I'm not using them.
     

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