Is it every HDMI devices will have such interference, or only certain kind of devices?

What is your location (city and state)? Have you tried manual scan (enter frequency manually and scan for channels)?

3C-2V is 41dB/100m @ 750 MHz
5C-2V is 29dB/100m @ 750 MHz
RG6 is 18dB/100m @ 750 MHz

The 3C-2V should be skipped, the 5C-2V is ok at shorter lengths if in good condition

The old coax types were only for VHF band I and III over any distance, remember that it was latecomer NTV7 that first used UHF

I really pening right now as I've tried to scan the channels but until now received nothing. I don't know whether my decoder broke down or what.

I bought a 5e antenna from shopee that come with rg6 cable but still got no signal. Quality is never above 60% meanwhile strength is always 0%. That makes me really pening. Meanwhile on decoder after scan has finished and no channels received it shows "empty database".

Need some advice from all sifus here

This post has been edited by Hzz: Oct 20 2019, 10:13 PM

So far from my experience, it's devices that are transmitting 1080p60 signal such as AV Receiver and laptop. The moment the signal is off, the signal quality of DVB-T2 increases. Probably depends on HDMI cable used too (how good is the shielding) and the HDMI clock frequency used by the devices (whether is has harmonics that are similar to the DVB-T2 frequency). But since repositioning my cables and changing to RG6, the DVB-T2 signal quality doesn't get affected no matter the HDMI devices are transmitting or not. It's now stable at 90-100 signal quality.

I also used to have degraded signal during heavy rain but it's now stable after repositioning the antenna.

This post has been edited by AV_2018: Oct 20 2019, 10:19 PM

What decoder are you using? Got signal quality but totally no signal strength seems like faulty decoder. Usually can't have quality if there is totally no signal.

thanks for the insight



for past two days, i was unable to resolve, unable to received RTM based channel, and only prima media one. signal strength is about 54%, now i isolate the hdmi cable with aluminium foil. and it works.

my antenna is high rise building master antenna system.

hope this help others

Sounds like you have a cheapo hdmi cable

[quote=AV_2018,Oct 20 2019, 10:22 PM]
What decoder are you using? Got signal quality but totally no signal strength seems like faulty decoder. Usually can't have quality if there is totally no signal.



B*tat* brand that i bought from lazada. I messaged them on lazada they keep saying maybe problem from antenna. Actually before this I've use this decoder with old antenna and it is working fine. But due to some renovations on my house, i put this decoder aside for about two months and because i already using iptv for living hall. This decoder i put it for my bedroom tv.

This post has been edited by Hzz: Oct 20 2019, 10:46 PM

Or cheapo antenna cable. But can't say cheap also; some affordable cables might be better shielded than more expensive cables.

Since you're in Klang Valley area, just manual scan this frequency 666MHz (also known as Channel 49) to get Media Prima and other channels.

the hdmi came with the decoder which i get it from lazada

It was bundled free, so cheapo then.
Don't get ripped off for exotic hdmi cables from hifi shops, they are often trash in a fancy box

Ohh I see...
But when someone can't get digital TV signals, and then
"I don't know what is my cable type. My wiring there doesn't have any labels, and didn't state if it's 3C-2V, 5C-2V or RG6 or RG6/U."

If ask them to identify and "measure" the cable diameter seems a little impractical and would likely give up to go and "measure" this kind of things. 😂😂😂

If this happens, how would you advise the person to check what's the cable type? Or just ask, the cable has been there for how many years already? If the cable is more than 10 years ago, advise them to just change new one, or how? (If the cable has already 10+ years, it shouldn't be a big problem, isn't it? )

Wow... I didn't know that.
Can you take photo of what you did to your HDMI cable, like how you shield the cable with aluminium foil.
Thanks a lot

Cable does not wear out with age, it is spoiled by water getting in or rubbing against something

[quote=Hzz,Oct 20 2019, 10:41 PM]
[quote=AV_2018,Oct 20 2019, 10:22 PM]
What decoder are you using? Got signal quality but totally no signal strength seems like faulty decoder. Usually can't have quality if there is totally no signal.

B*tat* brand that i bought from lazada. I messaged them on lazada they keep saying maybe problem from antenna. Actually before this I've use this decoder with old antenna and it is working fine. But due to some renovations on my house, i put this decoder aside for about two months and because i already using iptv for living hall. This decoder i put it for my bedroom tv.

[/quote]
I had this issue when I plug in HDMI into my cheapo projector, when I plug it in, then I get no signal, when unplug, then got signal.... play around with the indoor antenna until the cable broke( aerial cable), no longer have this decoder with me anymore, already deployed it at my aunt’s house, no issue with that TV(sharp LCD TV)

Some cables do wear out with age. Can see the rubber/PVC change texture over time even if just mounted on indoor wall or kept in a drawer after a really long time. But usually it's spoiled by sunlight and other factors.

Digital TV reception may be affected by improper antenna installation and fake decoders - SoyaCincau.com

True. It is possible also. But from what I see, they put all the blame to the viewers of not able to receive strong and stable DTT signal.
They must be receiving overwhelming negative responses from netizens and MCMC.

I'm pretty sure many people didn't realise that poorly shielded HDMI cable can cause interference to TV signals. They should first advice users to unplug or power off every single devices near TV that uses HDMI (like Astro, android TV box, karaoke system, home theater system and others). Once it's off or unplugged, then only scan for channels and monitor the signal readings while aslifn antenna until uou get signal. As you turn on the devices one by one. When one device causes significant signal drop, or become no signal, go change to another hdmi cable.


According to the company, frequency restack (within 470-690MHz) can be done in 6 months after analogue switch off. So have to wait for few months then only we shall see some improvements.

And I hope MYTV will increase the video and audio bitrate to at least 6Mbps and 80kbps HE-AAC V1 respectively.

If using an outdoor antenna with strong signal strength and properly shielded and terminated coaxial cable, it should be unaffected by HDMI cables. Anyway, hope they'll change to a lower frequency so that it isn't affected by wet roofs and HDMI interference. Even 650MHz and below is an improvement compared to 682MHz. Hope the bitrates will be increased too as there is some micro-blocking during fast motion and complex scenes.

Addon: Those using 3rd party decoder might want to make sure resolution is set to 1080i instead of 1080p or it may interfere with itself. From experience it seems 1080i doesn't interfere when 1080p does. I suspect it's because when at 1080p, some devices use a higher HDMI TMDS frequency which interferes with certain MUX frequency. A properly shielded and terminated RG6 or HDMI cable and a strong DVB-T2 reception should prevent interference issues though.

This post has been edited by AV_2018: Oct 21 2019, 12:45 PM