Video over IP troubles w Convex device.



  • Hey all,

    Had a heck of a time with some Convex CV-CATHDMITX2  video-over-ethernet devices yesterday.

    It was the weirdest thing.  We had four sets, and several cables.

    We were getting just grey fuzzy screen in some combos, sometimes we got only miscoloured (yellow/purple only) image.

    Rental house tech said it might be an HDCP issue.  But in his heart of hearts he thought it was because we were on Mac, which made my brain boil.  I mean the device should take an hdmi signal from MDP, it works on any other display or device...

    We did testing and discovered that a mini-display-port-to-HDMI cable -> transmitter -> rj45 cable -> receiver -> HDMI projector combo would work, but then switching to a different receiver, port, computer, projector, cable, receiver, adapter anything - might break it.  Or might not.

    Fine, I could live with that - test and install - but then when I ran the cable to the booth instead of just testing it in a coil on the floor, it failed again.

    WTF, Convex!!!?!

    This picture is the transmitter I think.

    4d4878-voe-001.jpg



  • PS - we ended up replacing one with an Extron DTP HDMI 230 Tx which worked fine, and then just used verdammt VGA cables for the other two.


  • Tech Staff

    HDCP is a bitch! To be polite. Very strange though...



  • I have used super cheap and nasty HDMI over cat5 from eBay before and had no troubles. Being cautious I use cat6 cables instead. There are quite a few HDMI to hdsdi and hdsdi to HDMI convertor boxes going cheap on eBay these work really well and the coax for transmission is cheap and reliable and very easy to repair. I doubt this was HDCP as it worked from one output. HDCP comes in only when you can some devices in the chain which are not HDCP compliant and some that are. Generally other wise if there are all or none HDCP compliant stuff everything will work fine.



  • Yes many, many heads were scratched that day.  It may just be that convex sux.



  • Fred,

    What kind of cable do you use for HDSDI over coax?  Would plain BNC cable work?

    And what is the make / model of those HDMI over Cat5 boxes?



  • The HDMI over cat 5 are unmarked chinese things. I think it is roulette buying them but me (and others I know) got pretty lucky - I am sure the geffen solution is less of a gamble.

    For HDSDI I go a bit overboard but with good results. I use Belden 1505f it is super high quality and good if it is going to get a bit of a beating and get trampled on and used a lot. It is also good quality enough to go long distances without errors.
    I have used pretty generic cable ( I even have a 50m reel of it). It works fine but this depends of the quality of the devices you are connecting to it. Once the number of errors in the signal that reaches your receiving device is over its threshold you get no picture at all. for short runs you have much less danger and plain BNC will do OK. Test with the actual equipment you want to hook up first if you are doing it cheap


  • Ok cool - monoprice has some interesting hdmi-cat5 adapters around $40, there's a store here (lee's electronics) selling them in store.

    http://www.monoprice.com/Product?c_id=109&cp_id=10110&cs_id=1011012&p_id=8121&seq=1&format=2


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