How long can an HDMI cable be?

toxcrusadr

Omelette au Fromage
My new cable TV setup messed up one thing. My basement TV had a cable box and I used the cable-out jack to run about 25-30 ft of coax to a small TV on the shop bench so I could watch whatever was on out in the main room. The new box is tiny and has HDMI, SPDIF and audio/video line level RCA jacks for outputs. Any suggestions which would be best for a run that long?

I think I have a TV modulator somewhere so I could convert to Ch. 3 and run cable but it would probably not be very HD. It would work though, if nothing else does.
 
Reliable HDMI length depends on the signal you are running through it. If it is 720p or 1080i broadcast you can get passive cables good for 50'. Sounds like that's what you'll be getting out of your cable box so you should be good to go.

4K HDR10 and passive cables start to fail at under 20'.

Tom
 
Awesome guys, thanks!

Here's another question that further reveals my cluelessness about HDMI. It does not see to have 'in' and 'out' like line level jacks on equipment. The cable box has 1 HDMI jack. If my main TV has two HDMI jacks, and I bring signal into #1, does #2 then work as an output that I could run this long cable from? I assume not, which means I'd need an HDMI splitter of some sort.
 
The TV has two inputs...not input and output.

Simple HDMI splitters often cause "handshake" issues. Spend more to get a better amplifier type splitter.

Any chance the cable box has component video outputs (red, blue, green RCA + red & white for audio) and your distant TV has the matching inputs? Going analog can avoid the handshake issue but only crazy people (like me) will have 5 50' RCA cables. Hint - RCA compression fittings on coax cable make this reasonable if you have the coax tools.
 
Cable box has a yellow composite video and red/white audio outputs, could use that too. Never thought about putting RCA jacks onto coax cable, nifty idea. I do have compression tools for working on antennas and stuff. I'll look into that and also what it would take to get an amplified HDMI splitter.

Thanks!

Seems TV and cable gear is going toward fewer and fewer inputs and outputs these days, which I'm sure makes them cheaper to build, but the more the merrier in my book.
 
Looks like the cheapest approach would be coax cable with RCA connectors. Assuming I have the cable laying around, I'd need three times the distance so have to see. Connectors are a buck or two and I already have the tools.

HDMI cables are about 50 cents to a buck a foot in this range, say $20 for that, and an amp/splitter is at least another $30 at PE so that's quite a bit more in total. This is just the shop TV so I'm going to try cobbling up the coax RCA cables and see how that works.

Thanks again y'all! I think I got a plan.
 
Try the yellow video cable first. It will be standard definition and you may hate going backwards in picture quality though may be good enough for garage use.
 
I have 3. 25 ft cables I run between my display, Apple TV and HT processor that I bought from Parts express and have experienced no issues with 1080P. But for 4K you might want to do some serious research.
 
The TV I'm feeding with this cable is a 10 yr old 19" tabletop that probably maxes out at 720 so I'm not concerned about losing quality or getting a 4K signal from one end to the other. :biggrin:
 
I'm far from an expert in this stuff.... indeed, I've not even yet graduated to dumbazz level....

That said, I thought/think you can also do HDMI over CAT-5/6 where you have some form of signal converter at both ends and in between them, you connect them with CAT-5/6.

At one time, I think you might have needed two (or four?) lines of CAT-5 to get the signal. I don't know.

I just know that I ran two 45' lengths of HDMI across my room and it worked. As a backup I also ran four lines of CAT-6 to each location in case something happens in the future.

I think if you did a search on "HDMI over CAT-5" you might find something.

Example: https://www.amazon.com/d/Computer-Audio-Video-Accessories/HDMI-over-CAT5-HDBaseT-Extender/B00HQBGZR8
 
Darn, I had several remnant rolls of CAT-5 a couple years ago that had been discarded at a construction site, but I sold them. This is why I usually keep everything. :biggrin:
 
My new cable TV setup messed up one thing. My basement TV had a cable box and I used the cable-out jack to run about 25-30 ft of coax to a small TV on the shop bench so I could watch whatever was on out in the main room. The new box is tiny and has HDMI, SPDIF and audio/video line level RCA jacks for outputs. Any suggestions which would be best for a run that long?

I think I have a TV modulator somewhere so I could convert to Ch. 3 and run cable but it would probably not be very HD. It would work though, if nothing else does.
I believe that 50' is the longest reliable HDMI cable. I use this 30' cable from Amazon for a 4k run with no visual problems.
https://www.amazon.com/Cable-suppor...qid=1544533575&sr=8-3&keywords=30'+hdmi+cable
 
Though, I have no experience with the Stellar Labs Redmere active" HDMI cables, and don`t know what their max available length is.
They used to be offered in the MCM flyers sent to my house, might be something to consider looking into..

My house`s 6 room 1080P @24 frame HDMI is fed via active translator/transcoder via asingle line(4 twisted pairs) Cat. 6 distributed video have runs of around 75ft. + at the farthest location, work very well since the 2009 Ethernet cables install, and that`s with the installed RJ-45 T- base 1000 signal, well earthed surge/spike protectors at both the master send and end points.

Which, these protectors have a bit of signal loss, as determined, via my Byte Brothers Real World Ethernet Certifier, by me.

Important here in the upper end of FL.`s "lightning Alley" to protect all attic run interconnections to expensive A/V equipment from Nature`s destructive EMP blasts !!

Good luck with your long HDMI cable quest.
 
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