My Humax Forum » Freeview HD » HDR 1800T, 2000T

Poor and Sporadic Reception

(19 posts)
  1. chickenlegs

    chickenlegs

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    I have a Humax HDR-2000T connected to a fairly old Pioneer TV. A coax cable connects the Humax to a wide-band roof mounted aerial and is looped into the aerial port on the TV via the antenna connections. The aerial cable that comes from the external aerial is connected to a Maxview masthead amplifier MHA26U and in turn, connected to a Signal Booster, SLx TV Amplifier Four Output 27820BMR. The Humax is running software UKTFAC1.01.18 - I have tired to check whether updated software is available, but the Humax never seems to establish a connection, even though the internet connection appears to be established and working (the Humax TV Portal doesn't work either). I have tried to disconnect the booster and MHA, but this results in a lack of signal message on all TVs connected to this setup.

    We have recently had our external aerial repositioned after it rotated in high winds. It is now pointing, (as others are locally), toward Bristol Illchester Crescent transmitter. The Humax has been retuned.
    My issue is the poor reception of some, non-DTV channels, particularly ITV3, More4, Dave, and E4. This intermittent reception drop affects recordings with some failing altogether or the pictures of each one breaking up. I have checked the strength and quality of the most problematic channels and they (sometimes) show 75%, 75% for each. Unfortunately, this issue is not constant and the signal strengths appears to fluctuate. For example, last evening it was so bad that we couldn't watch the non-BBC channels, but this morning they seem to have recovered.

    In order to narrow down the issue, I have disconnected the Humax from the aerial cable and plugged this directly into the TV and when viewing channels solely via the TV have not noticed any signal loss or break-up. Other TVs in the house that are not provided with a Humax work flawlessly - these are connected to the same aerial, aerial cable and boosters.

    This indicates to me that the fault might lie with the internal tuners in the Humax. Would this be a sensible conclusion? Your advice would be much appreciated.

    Many thanks. Chris

    | Wed 25 Sep 2019 14:56:22 #1 |
  2. grahamlthompson

    grahamlthompson

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    Try removing the amplifier and connecting the aerial directly to the Humax box using a coax coupler. The box may have a more sensitive tuner than the TV and the level is high enough to cause signal clipping.

    | Wed 25 Sep 2019 15:53:54 #2 |
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    Martin Liddle

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    chickenlegs - 4 hours ago  » 

    We have recently had our external aerial repositioned after it rotated in high winds. It is now pointing, (as others are locally), toward Bristol Illchester Crescent transmitter. The Humax has been retuned.

    How did you do the retune? Have you checked that the Humax is receiving on the correct set of multiplex channels? If in doubt try a manual tune using the instructions at https://myhumax.org/forum/topic/transmitters#post-2336

    | Wed 25 Sep 2019 19:10:13 #3 |
  4. Trev

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    chickenlegs - 4 hours ago  » My issue is the poor reception of some, non-DTV channels, particularly ITV3, More4, Dave, and E4.

    Just to clarify a point, DTV is an abbreviation for Digital TeleVision. All Freeview TV transmissions are now digital. So there are no non-DTV channels.
    (But we know what you mean. Probably what could be considered by some as non-mainstream channels)

    | Wed 25 Sep 2019 19:11:32 #4 |
  5. chickenlegs

    chickenlegs

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    How did you do the retune? Have you checked that the Humax is receiving on the correct set of multiplex channels?

    Well I did a full Auto tune as I was not confident in doing a manual one, but now I see the instructions, I will give it a go. Thank you for the linked instructions.
    Whilst looking at the methodology, I checked my local transmitter (I am confident in it being the right one as this has been confirmed by a couple of electrical and tv engineers), and wrote down the channel numbers listed on the digitaluk.co.uk web site. I then went through each one as if I was doing a manual tune. There appear to be TV services within each of the multiplexes (BBC A, D3&4, SDN, ARQA and ARQB, except number BBC B (Ch 47). This one doesn't appear to have any service information associated with it. I will try and complete the manual tuning instructions and see if this helps. Many thanks for your helpful replies.

    | Wed 25 Sep 2019 20:26:17 #5 |
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    Martin Liddle

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    grahamlthompson - 4 hours ago  » 
    The box may have a more sensitive tuner than the TV and the level is high enough to cause signal clipping.

    I wouldn't have thought the quoted 75% signal strength was too high?

    | Wed 25 Sep 2019 20:36:05 #6 |
  7. grahamlthompson

    grahamlthompson

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    chickenlegs - 7 mins ago  » 

    How did you do the retune? Have you checked that the Humax is receiving on the correct set of multiplex channels?

    Well I did a full Auto tune as I was not confident in doing a manual one, but now I see the instructions, I will give it a go. Thank you for the linked instructions.
    Whilst looking at the methodology, I checked my local transmitter (I am confident in it being the right one as this has been confirmed by a couple of electrical and tv engineers), and wrote down the channel numbers listed on the digitaluk.co.uk web site. I then went through each one as if I was doing a manual tune. There appear to be TV services within each of the multiplexes (BBC A, D3&4, SDN, ARQA and ARQB, except number BBC B (Ch 47). This one doesn't appear to have any service information associated with it. I will try and complete the manual tuning instructions and see if this helps. Many thanks for your helpful replies.

    Without knowing which transmitter there is no way of telling which transmitter uses UHF for which MUX.

    Adjacent transmitters (apart from a few using SFN's (single frequency networks) have to use different Mux frequencies to avoid co channel interference)

    Enter your postcode here and your house number here and tick the detailed view to give us a chance to at least help, I still reckon you have over amplified the source transmitter.

    http://www.digitaluk.co.uk/operations/about_the_coverage_checker

    Also add the direction tour aerial points and if the elements are vertically or horizontally aligned. In general (but not always) main power transmitters are horizontal and relays vertical (to avoid as far as possible interference).

    Where I live most use Sutton Coldfield (vertical) which a wood to the the North precludes the much more powerful transmitter while the clear view to the south allows a a loft aerial to deliver stable pictures from the Lark Stoke relay.

    I have seen some new local aerials erected by so called professionals pointed at Lark Stoke that are are horizontally mounted. They are losing a very large percentage of the available signal. Clearly they employed idiots posing as professionals.

    http://www.digitaluk.co.uk/operations/about_the_coverage_checker

    Why have you ignored my suggestion to check if you have too high a signal ?.

    Pulling out two cables at the amplifier and connecting them together would immediately cofirm if the signal is simply too high.

    Your local transmitter (if we knew which one would help) may have changed the frequencies used for it's MUX and your existing group aerial may not now cover the frequency range required.

    Look at aerial gain curves here.

    https://www.aerialsandtv.com/atvstockaerialtests.html

    If your transmitter was originally a group A transmitter and has now moved some MUX out of Group A you will likely need a new aerial ( London's Crystal Palace is a recent example).

    It's all down to the government moving TV channels out of the 700MHz band to release the spectrum for mobile devices.

    | Wed 25 Sep 2019 20:51:25 #7 |
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    A1944

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    Post 1 says Bristol Illchester Crescent transmitter.

    | Wed 25 Sep 2019 21:55:11 #8 |
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    A1944

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    Re Ch 47, don’t forget that you usually have to select DVB-T2 for the HD Mux when tuning manually.

    | Thu 26 Sep 2019 7:23:28 #9 |
  10. chickenlegs

    chickenlegs

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    Thank you A1944 for your prompt. I will take note.
    Thank you grahamlthompson for your detailed response. I am confident that the local (relay station) transmitter is Bristol Ilchester Crescent - this hasn't changed in the time we have lived here. The polarity on the aerial is also correct and not changed in 20 years. I haven't "ignored" your suggestion to check the signal strength. There are a few logistical things I need to do before I can due to the set up here; get into the loft, purchase a length of coax and a few connectors etc. As described earlier, I have been part way through the manual tuning process by looking at the digital.co.uk web site, but I will complete this once I have investigated the signal strength suggestion but I can't do this at the moment.
    I'll let you know how I get on.

    | Thu 26 Sep 2019 8:38:44 #10 |

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