FAQ
TL;DR: 20 m HDMI runs exceed spec; "Maximum HDMI cable length: 10 m (28AWG) / 15 m (26AWG)." One UPC decoder has one HDMI output, so two TVs can only mirror the same channel without multiroom. [Elektroda, Prof. SpecMiernik, post #16676555]
Why it matters: This helps you decide between an HDMI splitter for mirroring or adding coax/multiroom for independent viewing, and avoid rewiring mistakes.
Quick Facts
- Typical UPC decoders discussed here have 1 HDMI output, so direct dual‑TV hookup isn’t native. [Elektroda, lajkonik_2005, post #16675049]
- HDMI length guidance: 10 m (28AWG) or 15 m (26AWG); 20 m often fails without active gear. [Elektroda, Prof. SpecMiernik, post #16676555]
- Multiroom/second card enables different channels on each TV and may add a small monthly fee. [Elektroda, TELMOR_PL, post #16675111]
- Splitters mirror the same program only and may hit HDCP protection; active models are required. [Elektroda, Staszek z Chełma, post #16676045]
- Renovation tip: plan coax (e.g., RG6) and data cabling in conduits for future changes. [Elektroda, TELMOR_PL, post #16675193]
How do I connect two TVs to one UPC decoder?
Your decoder has one HDMI output, so it can feed only one display directly. To show the same channel on two TVs, add an active HDMI splitter after the decoder. To watch different channels, you need multiroom or a second card and coax run. [Elektroda, lajkonik_2005, post #16675049]
Can an HDMI splitter let both TVs show the same program?
Yes. Place an active HDMI splitter at the decoder, then run HDMI to each TV. Both screens will mirror the same channel. Some content may not display due to HDCP copy protection, so choose a splitter that handles HDCP correctly. [Elektroda, Staszek z Chełma, post #16676045]
Why does my 20 m HDMI cable give no signal?
It exceeds typical HDMI passive limits. "Maximum HDMI cable length: 10 meters for 28AWG; 15 meters for 26AWG." Long runs need thicker cable, active repeaters, or extenders. This failure is common on 20 m passive leads. [Elektroda, Prof. SpecMiernik, post #16676555]
Do I need multiroom to watch different channels on each TV?
Yes. Without multiroom or a second authorized card, a single decoder can’t independently serve two TVs. Cable systems prevent such redistribution. Multiroom usually adds a small monthly fee and solves this limitation cleanly. [Elektroda, TELMOR_PL, post #16675111]
Is coaxial cable only for old analog TV?
No. Coax carries digital cable and terrestrial signals as well. If you want live TV without the decoder on, your TV needs a coax feed from the antenna or cable outlet. HDMI alone won’t deliver broadcast channels. [Elektroda, TELMOR_PL, post #16675292]
Do Philips or Samsung TVs need special settings for HDMI?
Generally no. Select the correct HDMI input on the TV and ensure the decoder is on. For broadcast reception without the decoder, connect a coax feed and run the TV’s tuner setup. No extra HDMI‑specific tuning is required. [Elektroda, TELMOR_PL, post #16675292]
I can’t pull new coax to the kitchen; any routing tips?
Use skirting boards or surface‑mounted conduit to add coax discreetly. This avoids opening walls again. Plan a gentle path to the TV and protect bends. Many installs retrofit this way after renovations. [Elektroda, Prof. SpecMiernik, post #16675188]
What cabling should I have planned during renovation?
Include at least one or two RG6 coax runs plus Ethernet (e.g., UTP Cat5e) inside protective conduits. This future‑proofs for multiroom, network streamers, or access points. "Appropriate cables are placed... in a protective pipe." [Elektroda, TELMOR_PL, post #16675193]
How do I mirror my main TV to a second TV (same channel)?
- Place an active HDMI splitter at the UPC decoder output.
- Connect short HDMI from decoder to splitter, then HDMI from splitter to each TV.
- Power the splitter and select the HDMI inputs on both TVs.
This mirrors one program. [Elektroda, Staszek z Chełma, post #16676045]
Will a pricier 70 PLN HDMI cable fix a 20 m run?
Price doesn’t overcome physics. Passive HDMI beyond 10–15 m often fails, regardless of brand. Use thicker gauge, an active repeater, or HDBaseT/Cat extenders for long distances. Keep runs within spec for reliability. [Elektroda, Prof. SpecMiernik, post #16676555]
Can I send the UPC decoder’s output over coax to another room without extra fees?
No. Providers design systems to stop such redistribution. To watch independently on another TV, order multiroom or a second card and run proper coax. This complies with service terms and works reliably. [Elektroda, TELMOR_PL, post #16675111]
What is HDCP and why does it block my splitter?
HDCP is copy protection on HDMI links. Some splitters fail to authenticate properly, causing black screens. Use an active splitter that handles HDCP or expect certain channels to refuse playback. "You still need to bypass HDCP protection." [Elektroda, Staszek z Chełma, post #16676045]
I buried HDMI in the wall and removed coax. What now?
You will likely need to re‑run coax to the second TV to regain broadcast or multiroom capability. The thread author accepted small demolition to correct this and restore flexibility. Plan conduits next time. [Elektroda, lajkonik_2005, post #16676533]
Can one decoder really operate two TVs at once?
Only for the same channel, and only with extra hardware. A single HDMI output cannot independently drive two displays. Multiroom or a second card is the proper route for separate channel control. [Elektroda, Prof. SpecMiernik, post #16675096]
