Problems using HDMI over Cat5 Extender

[kevindickinson]

Don't know if this helps but I've been running humax to various TV's at work using cat5 to scart extenders without issue for a number of years.


Sent from here using a computing device.

 

[Tim.C]

At the risk of suggesting an obvious, but 'out of the box' (pun intended) suggestion.....

Why not buy a cheap second hand HD/HDR T2 and connect it to the second TV and then stream it over.

In fact, any cheap media streaming device - eg rasberry Pi

If you're after Live TV as well, you could also then run FilmOn or iPlayer etc.


Then everything is Cat5 or WiFi - easy

 

[geoffd]

Don't know if this helps but I've been running humax to various TV's at work using cat5 to scart extenders without issue for a number of years.

I guess I started out on the HDMI over Cat5 route because it seemed simple enough, just a splitter and an extender . There also seemed to be plenty of HDMI extenders with IR available whereas I didn't notice any scart extenders with IR, maybe because I wasn't looking for them. Scart output to the TV in the back room would have been fine in hindsight.

Why not buy a cheap second hand HD/HDR T2 and connect it to the second TV and then stream it over.

If, when I get my second hand HDR T2 off ebay, it doesn't solve my issues then this would be an alternative way of using it.

 

[Black Hole]

No problem. See Things Every... (click) section 6. The HD-FOX or HDR-FOX will do it out of the box, but using custom firmware makes remote playback and management indistinguishable from recordings hosted locally.

 

[Tim.C]

Just discovered something with mine which may help you, or could be something entirely different. !!

My HDR-T2 is currently connected by HDMI to a PC monitor, and it fails to bring up a picture most times it's turned on - error "mode not supported" on the monitor. However, I discovered that switching output modes with the vformat button makes it spring back to life, so I cycle through those back to 1080p and all is well.

I just thought that this must be doing some sort of handshake through the HDMI, so might also get yours to spring into life.

Worth a try........

 

[geoffd]

I discovered that switching output modes with the vformat button makes it spring back to life, so I cycle through those back to 1080p and all is well.

I just thought that this must be doing some sort of handshake through the HDMI, so might also get yours to spring into life.

Worth a try........

How long has that button been on my remote control?? Thanks Tim. Certainly worth a try and it was most interesting. Saves me having to use the Tosh to fix my broken picture! If I switch it to anything other than 1080p it fixes the picture. Switch back to 1080p and I get the broken picture back. I guess my LG TV was negotiating at 1080p and hence the broken picture while my Tosh was negotiating something lower and fixing it though why it didn't switch back when I went back to the LG is a mystery.

Meanwhile... my second hand HDR-T2 has arrived. I plugged it into the Matrix and the front room TV and it works! I then connected the other output from the Matrix through the HDMI Cat5 extender to the LG TV and that also works! Well almost. The picture on both the front and the back TV is not perfect when in 1080p (nothing like as bad as my original Hummy over the Cat5 extender) but if I step it back to 1080i using Tim's magic button then both front and back TV work great!

Just as a check I tried my original Hummy connected to the Matrix and the front room TV and nothing, no matter what I set the picture to. Quite a relief as I thought I might have shelled out for another HDR-T2 just because I didn't know about the vformat button. But it seems my original Hummy did have problems with its HDMI.

Thanks guys for all the input. Now can I interest anybody in a spare HDMI over Cat5 Extender, two HDMI splitters which may or may not work and an HDR-T2 with a dodgy HDMI output.

 

[Trev]

If I switch it to anything other than 1080p it fixes the picture. Switch back to 1080p and I get the broken picture back. I guess my LG TV was negotiating at 1080p and hence the broken picture while my Tosh was negotiating something lower and fixing it though why it didn't switch back when I went back to the LG is a mystery.

Presumably your TV will actually handle 1080p?

 

[geoffd]

Presumably your TV will actually handle 1080p?

Yes it will. I have tested it with a straight HDMI cable.

 

[Owen Smith]

Neither, until you've got a clue. What do you even mean by "power surge" anyway? How can turning on something so small cause a surge or a blip or whatever other meaningless term you care to invent? Really, people bandy these terms about like they know what they are talking about when in actual fact they haven't a clue. So, please free to enlighten us all with your engineering knowledge of such things.

With my previous hifi stereo amp, turning the kitchen main light (fluorescent with large old style ballast) on or off caused a small crack noise to come from the hifi loudspeakers. I never established whether the noise was radiated (RF) or conducted (on the mains). The old fridge turning on or off on its thermostat did the same thing, as did the central heating mechanical thermostat. The new fridge and new digital thermostat fixed those as sources, and my new multi channel AV amp isn't sensitive to the kitchen light.

However, turning the kitchen light on or off still causes a pixelation glitch on the HDR Fox T2 picture. I still don't know if it's a radiated or conducted problem. But a mains filter on the HDR Fox T2 and on the power supply to the mast head aerial amp made no difference, so I suspect but cannot prove radiated.

Short version: crappy noise happens with house electrics.

 

[antipodean]

With my previous hifi stereo amp, turning the kitchen main light (fluorescent with large old style ballast) on or off caused a small crack noise to come from the hifi loudspeakers. I never established whether the noise was radiated (RF) or conducted (on the mains). The old fridge turning on or off on its thermostat did the same thing, as did the central heating mechanical thermostat. The new fridge and new digital thermostat fixed those as sources, and my new multi channel AV amp isn't sensitive to the kitchen light.

However, turning the kitchen light on or off still causes a pixelation glitch on the HDR Fox T2 picture. I still don't know if it's a radiated or conducted problem. But a mains filter on the HDR Fox T2 and on the power supply to the mast head aerial amp made no difference, so I suspect but cannot prove radiated.

Short version: crappy noise happens with house electrics.

I agree with the short version ...

The symptoms described here would suggest radiated noise to me - mains wiring makes a great transmitting aerial for this sort of interference.

However for the OPs problem I suspect conducted noise. If the noise spike is of high enough voltage it will make its way through almost any filter. Even my electric jug can generate this sort of spike when it switches off. The switch lever is clear plastic so the neon indicator can show when the power is on, but when the switch to the element opens sometimes there will be quite a flash show from the contacts opening. This is probably what is causing the OPs problem.

One thing to try is running the unit through an isolation transformer - not an RCD, but a proper transformer. This stands a reasonable chance of filtering any mains bourne noise spikes from getting to your setup. We used to do this on small business computer systems that were susceptible to mains carried interference in industrial areas which had heavy machinery or welding gear around. In our case we used a 5KVA transformer - the bigger the chunk iof iron the better it was at filtering the noise, but for testing purposes I would use a 1KVA transformer, that should handle both the TV and the recorder.

 

[Andy Hurley]

At the risk of suggesting an obvious, but 'out of the box' (pun intended) suggestion.....

Why not buy a cheap second hand HD/HDR T2 and connect it to the second TV and then stream it over.

In fact, any cheap media streaming device - eg rasberry Pi

If you're after Live TV as well, you could also then run FilmOn or iPlayer etc.


Then everything is Cat5 or WiFi - easy

In my case it isn't a second TV, it's the first and only one, the reason I don't have the Hummy by the TV is because it is mounted on kitchen cabinets and there is no obvious place for the Hummy and even if there was it would get all greasy in the kitchen. I have my Hummy in the cupboard under the stairs which is convenient for power, aerial and network connections, the HDMI runs under the kitchen floor via a pair of cat5e cables which I installed when we moved in last year. One day we may put a TV in the sitting room in which case I will have to change things I suppose. The only issues I have with the current setup are occasional sparkles (presumably interference on the cat5) and the awkwardness of climbing into the cupboard to reboot when it crashes which is fortunately fairly infrequent.

 

[Black Hole]

...and the awkwardness of climbing into the cupboard to reboot when it crashes which is fortunately fairly infrequent.

Fit it with a remote-controlled power socket.

 

[Andy Hurley]

Could do (have a few spares around) but I like to see what is going on when the remote becomes unresponsive. There have been times when the front button will cause it to come to life and I would rather do that than power cycle if I don't have to. I can also monitor as it comes up to see if anything unusual is happening.

 

[zekepliskin]

Here's a question for any of the knowledgeable chaps who may or may not still be on this forum and using it after 3 1/2 years since the thread ended - how does anyone think this will react with a HomePlug situation? I've been thinking of adding a 19" TV I have lying around to the kitchen/breakfast table area and I wonder about the viability of HDR Fox T2 -> HDMI Matrix Splitter (I have a 1 into 4 lying around too) -> HDMI CAT5 converter -> 10/100Mbps homeplug -> opposing homeplug -> opposing HDMI CAT5 converter -> kitchen TV via HDMI? I'm speculating that 1080p is way too much to ask in terms of bandwidth so I'm happy to knock it down to say 576i for a stable picture.

 

[prpr]

HDMI over CAT5 is not ethernet. You cannot put it through an ethernet network device. It won't work.

 

[Black Hole]

Correct. These converters treat the Cat5 as a length of cable point-to-point. It is not data traffic that could be transmitted over an Ethernet network.

This subject came up very recently:

I've ordered a video over CAT5 Tx & Rx system, £35 from Amazon. I don't suppose these will work through a router and a switch, but I'll find out when I get it and post an update.

No it definitely won't. It's not using Ethernet to communicate, just the impedance-controlled Cat5 cable point-to-point.