HDMI degrades the signal

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Лис
Posts: 17
Joined: Sat Feb 16, 2019 7:25 pm

HDMI degrades the signal

Post by Лис »

Why when using HDMI signal level and its quality less than when using AV?
In Gtmedia V7 Plus using HDMI there is no signal or it is very weak. When using the AV output, the level and quality of the signal is normal.

Nero
Posts: 116
Joined: Wed Feb 27, 2019 4:24 pm

Re: HDMI degrades the signal

Post by Nero »

Лис wrote:
Sat Apr 20, 2019 10:48 pm
Why when using HDMI signal level and its quality less than when using AV?
In Gtmedia V7 Plus using HDMI there is no signal or it is very weak. When using the AV output, the level and quality of the signal is normal.

Try another HDMI cable.

pegasus07
Posts: 298
Joined: Sat Mar 16, 2019 4:30 pm
Location: Bayern

Re: HDMI degrades the signal

Post by pegasus07 »

What signal strength and what signal quality do you mean?
Are you talking about the strength and quality of the antenna signal?
I do not think you have the meter or the values to measure the HDMI signal?
It may be that your HDMI cable is defective and therefore can affect the input signal of the receiver.
Try as already suggested another HDMI cable
Best regards pegasus07
Don Quijote for satellite systems

Лис
Posts: 17
Joined: Sat Feb 16, 2019 7:25 pm

Re: HDMI degrades the signal

Post by Лис »

pegasus07 wrote:
Mon Apr 22, 2019 8:04 am
Are you talking about the strength and quality of the antenna signal?
Yes, about satellite antenna. Using HDMI reduces the quality of the satellite signal.
pegasus07 wrote:
Mon Apr 22, 2019 8:04 am
What signal strength and what signal quality do you mean?
Using AV.
strength 60
quality 50
Using HDMI.
strength 60
quality 0 - 38
When I use HDMI, periodically the screen turns black with the words "No signal". It happens every second.
I replaced the HDMI cable. It almost did not help. Quality signal increased by several percent, but still periodically there is message "No signal".

Marantz
Posts: 330
Joined: Thu Dec 28, 2017 5:36 pm

Re: HDMI degrades the signal

Post by Marantz »

Hi
I had something like this happen and i moved the cabling around and it stopped,seems like the signal from the HDMI was getting into the recievers sat input ,,i moved the hdmi cable to the left and coiled up the rest of it at the tv and moved the coax from the sat dish to the right side and got it away from the tv and the HDMI cable .

prior to this they were just mumble jumbled behind the TV

once in a while my sat positioner will drop it out too but not very often ,but that was cabling as well .

seems like poor shielding on cheap cables

Лис
Posts: 17
Joined: Sat Feb 16, 2019 7:25 pm

Re: HDMI degrades the signal

Post by Лис »

I replaced the HDMI cables and antenna cable and it did NOT solve the problem. I found that HDMI has a strong effect on the frequencies 10892 MHz and 11747 MHz.
Even the powerful signal disappears.
Without HDMI strength signal 80 and quality 74.
With HDMI strength signal 0 and quality 0.

This is observed in the frequency range 10873 - 11179 MHz and 11727 - 12034 MHz.
In fact, the range is larger, but outside the specified frequencies, the level and quality of signal only decreases, but does not disappear.

These frequencies have a common intermediate frequency has a range 1124 - 1434 MHz.

I replaced the HDMI and antenna cable. Connected to another TV and even to the converter HDMI-VGA. In all cases there was this problem.
This means that at this frequency there is a strong interference from HDMI or processor when activate HDMI. This is probably a hardware problem GTmedia V7 (tested on V7 Plus and V7 HD).

STRETCH
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Location: West Midlands UK

Re: HDMI degrades the signal

Post by STRETCH »

I use V7Plus/ V7s / V7HD / V7 Max all on various dishes ALL using a HDMI lead, the HDMI leads DO NOT degrade the signal to the TV screen.
I use a motorised system and pick up signals from various satellites between 46e to 30w.
What satellite is the problem that you get signal drop out.

Den

Лис
Posts: 17
Joined: Sat Feb 16, 2019 7:25 pm

Re: HDMI degrades the signal

Post by Лис »

What satellite is the problem that you get signal drop out.
On all satellites (Astra 4.8E, HotBird 13E and Amos 4W).
The signal disappears only in the specified frequency range 10873 - 11179 MHz and 11727 - 12034 MHz.
This corresponds to an intermediate frequency of 1124 - 1434 MHz on which the signal is transmitted over the antenna cable.

Лис
Posts: 17
Joined: Sat Feb 16, 2019 7:25 pm

Re: HDMI degrades the signal

Post by Лис »

I measured the noise at a frequency of 1147 MHz (this is an intermediate frequency for 11747 MHz). The sensor is a small antenna (wire 10 centimeters long) located near the GTmedia v7 box.

Noise when the GTmedia v7 box is off.
off.png
off.png (231.32 KiB) Viewed 1834 times
Noise when the GTmedia v7 box is on and using the AV cable.
AV.png
AV.png (230.91 KiB) Viewed 1834 times
Noise when the GTmedia v7 box is on and using the HDMI cable.
HDMI.png
HDMI.png (403.9 KiB) Viewed 1834 times
It is visible that from HDMI powerful and broadband noise. It interferes with satellite reception.

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Feralkiwi
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Re: HDMI degrades the signal

Post by Feralkiwi »

Something to check.

The electrolitic capacitors are usually inserted into the boards by hand, and can be forgotten / left out.
I have had units from other manufactures with electrolitic caps missing.

If a large cap is missing, the filtering of the power supply would fail and this interference could then happen.

The other thing to check is for earth loop / ground currents.
These can start from the sat dish ground pole and pass through the HDMi cable to the earth in the TV.
I have stopped some interference by running a AV cable as well as the HDMi between the TV and the Freesat unit to act as a larger ground path.

You could also try isolating the LNB mount so there is no earth connection there, if earth currents are the issue.
My biggest earth current is from the farm's electric fence. I have had DiSEqC switches burnt out when there are shorts on the fence.

Owen
Dishes; 3x3m, 2.4m and 4.1m, 10+ ku, 2 movers, USARLS. V8 Combo, Pro, V8 Golden, Nova V8Pro2, GTC, Super.V7HDs, Combo and V7s V7Plus Finder, Finder-Meter V8X / UHD V7Pro GT/XCombo. Sats 100.5E to 177W. I'm a Sat hobbyist who helps out.

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Lining
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Re: HDMI degrades the signal

Post by Lining »

Лис wrote:
Mon Apr 22, 2019 1:40 pm
I replaced the HDMI cables and antenna cable and it did NOT solve the problem. I found that HDMI has a strong effect on the frequencies 10892 MHz and 11747 MHz.
Even the powerful signal disappears.
Without HDMI strength signal 80 and quality 74.
With HDMI strength signal 0 and quality 0.

This is observed in the frequency range 10873 - 11179 MHz and 11727 - 12034 MHz.
In fact, the range is larger, but outside the specified frequencies, the level and quality of signal only decreases, but does not disappear.

These frequencies have a common intermediate frequency has a range 1124 - 1434 MHz.

I replaced the HDMI and antenna cable. Connected to another TV and even to the converter HDMI-VGA. In all cases there was this problem.
This means that at this frequency there is a strong interference from HDMI or processor when activate HDMI. This is probably a hardware problem GTmedia V7 (tested on V7 Plus and V7 HD).

Thank you for your test, please check your test environment

I tested what you said 10873 - 11179 MHz and 11727 - 12034 MHz.

I am plugging and unplugging the HDMI cable here, the signals are normal and have not been affected.
35BAD0C1FE4B6B452A35A20D3717171D.jpg
35BAD0C1FE4B6B452A35A20D3717171D.jpg (189.92 KiB) Viewed 1785 times
QQ图片20190424185330.jpg
QQ图片20190424185330.jpg (217.4 KiB) Viewed 1785 times
FREESAT brand change GT MEDlA

kolithawick
Posts: 222
Joined: Wed Feb 01, 2017 4:16 am

Re: HDMI degrades the signal

Post by kolithawick »

I think your test results are normal. From the pics I can see noise is about 20db higher with HDMI. This can be explained, with AV you will not get any high frequencies so radiated noise is low. With HDMI with high data rates in the range of gbs you will get more high frequency noise.
What I feel is this must be a problem of shielding.
inside the box, cabling , or the positioning of the equipment.
To clarify this can you please do this.
pls do the same test with other equipment and see the results. any other equipment with AV and HDMI. Bluray etc.

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