"SURVEY OF ISSUES - DIAGNOSIS - TREATMENT
Have you been facing, either from the outset or suddenly or gradually, issues with TNT reception (pixelation, black screen, freezing, random or partial reception, missing channels or multiplexes ..) but you do not know the cause or causes.
Here is the list of possibilities or origins and lines of thought, solutions, for research on a private individual antenna .. 1 - Is your transmitter or relay equipped with TNT SD and especially HD (R5)
2 - Have the frequencies or emission parameters of the multiplexes undergone a recent restructuring/modification
3 - Are you sure you are within the coverage area of the transmitter (sufficient dBµV/m field strength)
4 - Is your site free from inter-transmitter interference (SFN or co-frequency or co-channel)
5 - Are you in a windy or mountainous area, producing harmful, variable, mobile or fixed echoes?
6 - Does your antenna have compatible characteristics (UHF bandwidth, directivity, front/back ratio)
7 - Does your antenna have compatible performance (dBi or dBd gain according to BER)
8 - Is your antenna well cleared (on the roof with a mast) and free of major obstacles, natural (e.g. uneven terrain, forest) or artificial, in the axis
9 - Is your antenna installed in the attic/loft (under the roof) always bathed in a sufficient and clean field
10 - Is your antenna well directed (misalignment?) and towards the "correct" transmitter
11 - Is your antenna well in the appropriate polarization, H or V, and is it well symmetrized...
12 - Is the dipole/cable connection at the antenna box (balun) correct (without oxidation)
13 - If you have a coupler, does it allow useful frequencies to pass through?
14 - Is the coaxial cable used still suitable (too much loss), does it show signs of deterioration?
15 - Are the connectors, plugs, suitable and do they ensure a perfect contact (plugging)
16 - Is your wall socket well compatible and correctly wired
17 - Is your connection cord between the socket and the TV input well made
18 - At this stage, how much margin in dB do you have at the socket, none, 10 dB reserve, or more, or less
19 - Do you live in the immediate vicinity of a powerful transmitter, is your receiver not saturated (norm, max 70 dBµv)
20 - Do you notice the presence of a molded "T", if so, get rid of it immediately, replace it with a 2-way splitter
21 - Do you have a "small" collective domestic antenna infrastructure (micro-TV network) for several televisions in the house, including a splitter or a tap, have you checked it
22 - Are you using a UHF mast preamplifier that is well powered (5 to 24 V, depending) remotely by the power supply transformer, via the coaxial cable
23 - Are you using an amplifier with selective filtering in the UHF band or a reduced bandwidth filter or channels
24 - Are you using an internal distribution amplifier (with or without splitting), is it properly powered directly from the 220 V socket (attic in general)
25 - Are you using an amplified indoor antenna (or a compact discreet outdoor one), working under +5V, is it well powered by the TV or the TNT adapter
26 - Have you properly disabled the "amplifier" power supply function in the TV and adapter, on an installation not having it (= "short-circuit")
27 - Is the gain from amplification in line with the losses
28 - Are you using a preamplifier, or even an amplifier in cascade, are there saturation issues (input and/or output signal amplified too strong = black screen)
29 - Are you experiencing freezes, and does you or your surroundings use various electrical and electronic devices creating problems (due to impulse)
30 - Is your electrical distribution installation compliant (EMC)
31 - Does the weather, climate, moment have an influence on the result
32 - Do you suffer from freezes or pixelation when any motorized vehicle passes by
SOLUTION TREATMENT:
one or more of these characteristics can possibly be addressed by one or more of these actions:
- Check the alignment of the antenna, and/or
- Replace the existing antenna with a higher gain UHF antenna, 19.5 dBi, and/or
- Look for a better reception location (sometimes under) the roof, and/or
- Raise the height of the mast, and/or
- Renovate the coaxial drop line (type 17 Vatc or Patc), and/or
- Install a UHF antenna preamplifier at the top of the mast, or an amplifier in the attic, and/or
- Check input and output levels, and/or
- etc...
for info, protocol without guarantee of result in certain regions with SFN plates or mountainous regions, echoes too long > IG/Km.
Issues other than reception, other than antenna and installation:
Is your audiovisual equipment in the living room well chosen (Mpeg 4), installed, set up and connected + connections and not affected by a breakdown. If you have moved, changed regions, (or transmitters) have you conducted a new search .." (short excerpt ZHD)
Long version for experts: detailed all these hypotheses:
https://www.jechange.fr/telecom/internet
