Long distance signal transmission can be carried out by the coaxial cable. Your PC/DVD/Set-top box with HDMI can play on old TV that without HDMI. 1 x HDMI To RF Converter. Output picture quality will be lower to RF analog signal(more like 480p).
eBay
HDMI Switch With Audio extractor 4K 60Hz HDMI Audio Splitter 2 in 1 out HDMI to Coaxial+toslink Spdif +L/R Stereo Audio+HDMI ARC
Aliexpress UK
CAMWAY HDMI ARC Audio Extractor ARC to Optical/Coaxial Audio Splitter Supports 192 KHz Audio for TV to Speaker AV Amplifier Enhance Audio Experience(Not for HDMI eARC TV)
eBay
MOSHOU HDMI 2.1 Coaxial Flexible HDMI to HDMI Cable 48Gbps eARC HDR 8K 60Hz 4K 120Hz for TV Box PS5 Laptop
Aliexpress UK
Professional Latex Paint Edger Brushes Wall Ceiling Corner Painting Brush Hemper. HDMI-compatible coaxial output, which can transmit signals over long distances through coaxial cables and use them in different rooms.
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HDMI Matrix 4X2 4K 60Hz 4 in 2 out Matrix HDMI with Audio toslink/coaxial port supports HDR HDMI ARC 4K 60Hz for PS4 P5 Xbox TV
Aliexpress UK
Converts HDMI input to DVD-D and (analog or digital) audio output. Compatible with HDMI 1.3. Output Port 1xDVI-D, 1xCoaxial, 1x3.5mm audio jack. Types Converter. Input / output resolution: 640x480 60/72/75/85Hz, 800x600 60/72/75/85Hz, 1024x768 60/70/75/85Hz, 1152x864 75Hz, 1280x720 60Hz, 1280x768 60Hz, 1280x800 60Hz, 1280x960 60Hz, 1280x1024 60Hz, 1360x768 60Hz, 1440x1050 60Hz, 1440x900 60Hz, 1680x1050 60Hz, 1600x1200 60Hz, 1920x1080 60Hz.
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Coaxial HDMI 8K HDMI 2.1 Cable, Ultra High Speed 48Gbps, Ultra Thin HDMI Cord Φ2.5mm, 8K@60Hz, 4K@240Hz, Dynamic HDR, eARC
Aliexpress UK
This HDMI to AV converter is a universal device for HDMI 1080p (60Hz) input to RCA (or BNC) analog output. Convert HDMI signal to RCA (or BNC video) and FL/ FR stereo audio signal. Check your TV input connector should be BNC, not F-Type, otherwise you need another adapter.
eBay
Ultra Thin HDMI 2.1 Cable Coaxial 8K Hyper Super Flexible Slim HDMI Cord 48Gbps eARC HDR 8K 60Hz 4K 120Hz for TV Box PS5 Laptop
Aliexpress UK
Long distance signal transmission can be carried out by the coaxial cable. Your PC/DVD/Set-top box with HDMI can play on old TV that without HDMI. 1 x HDMI To RF Converter. Output picture quality will be lower to RF analog signal(more like 480p).
eBay
USB Digital Interface Coaxial SPDIF/HDMI Output (UAC-1)
Aliexpress UK
HDMI input, HDMI output, coaxial output, fiber output, I2S output, HDMI OVER I2S output. The output mode can use I2S/fiber/coaxial, which is used to connect the decoder to improve the sound quality.
eBay
Unnlink HDMI Audio Extractor HDMI to SPDIF Optical Toslink Coaxial 3.5 Aux+4K HDMI Converter for TV box to TV Soundbar Amplifier
Aliexpress UK
Experience dynamic HDR with enhanced audio fidelity using this 8K Micro HDMI to HDMI 2.1 Coaxial Cable. Enjoy vivid, high-quality pictures and object-based surround sound formats, all at an ultra-high speed of 8K@60Hz.
eBay
4K HDMI Switcher Audio Extractor 2 in 1 Out Selector with R/L Toslink SPDIF COAXIAL Audio out HDMI ARC Audio Switch 2x1 Adapter
Aliexpress UK