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Sky HD/HDMI over Cat6 problems


Established Member
I've been having some problems trying to get my Sky HD set up via Cat6 ethernet cable and a HDMI extender (admittedly a cheap one).

I initially had a 15m or so run of Cat5e cables set up, however in 1080i mode I was getting flickering so I ordered some Cat6 shielded cable. I've replaced the Cat5e cable with Cat6, however when I was getting no signal at all in 1080i mode. I tried re-terminating the Cat6 cable a number of times (which is a real pain!) and bought a cheap ethernet tester - which doesn't show up any problems.

If I change the Sky HDMI mode to 540p, I get a picture which suffers from flickering. But 1080i, I get no signal. I'm in a worse situation now than with the Cat5e cable!! Is it a problem with the cable, my termination or interference? Thx

Joe Fernand

Distinguished Member
AVForums Sponsor
Unshielded, solid core, Cat6 is usually best - and careful termination a must have!

Once you know the cables are good you can focus on the quality/compatibility of the Extender pair you are using.



Established Member

I was going to post an update as I've been fiddling around with it for some time.

Basically, I am pretty sure it's down to my termination of the RJ45s. I ran some new cable not in the conduit to test if the cable I had already layed was kinked or something. The breakup/flickering was worse.

I am using Cat6 RJ45 connectors, but not entirely sure how to terminate the shield/braided wire. The connectors I'm using are not shielded ones, just the standard Cat6 Maplins connectors.

Can you recommend some Cat6 cable/connectors? Is it best to get someone in to terminate them?

I read some things on here about using shielded Cat6 if running close to powerlines etc - the conduit I am using for the Cat6 is next to a two-gang plug and the transmitting balun is located in a room where the house power cables come in/2 consumer units are.


Distinguished Member
Cheap cable works better because it has lower capacitance than big thick heavy cable. CPC | CPC - Over 100, 000 products from one of the worlds leading distributors of electronic and related products. do some specific Cat5 AV cable for less than £10 for a 20M length that offers better performance than standard Cat5. I have not tried it on Cat6 equipment, but the difference between on that sort of length leads me to think it will work OK. Cat5 & Cat6 differ very little, the cable "Skew" or how tightly it is wound and the thickness of the conductors being the main differences.

Terminating the cable:
You can buy shielded Cat 6 connectors. Ensure you are wiring them correctly. To acheive correct balanced line connection they must be connected as per the attached link. Cat 6 Wiring Diagram, Cat 6 Cable Wiring Diagram: CAT6 Wiring A common mistake is to wire them pin for pin, without the split pair.

Use a good quality crimp tool and ensure you strip the outer cover off to the specified length and do not touch the cable insulation. This will be punched through when you punch down. This should connect all 8 pins and push the cable clamp in at the same time. Do not try to push the connectors in indivudually.

Connect the braid at the "Sky" end only. this will avoid any hum loops that will manifest themselves as signal insatability. The braid is normally connected via the cord grip within the RJ45 plug. Simply stip the outer insulation off and leave the braid to enter the plug.

Hope this helps !


Established Member

I have finally figured out 100% sure it's down to my terminating.

I read what you said + looked to some Youtube videos - ran some Cat 5e and terminated them properly. No issues now getting 1080i via Sky HD. A real pain though that I didn't check this before pulling out the existing Cat5e and replacing it with Cat6 STP!!

I still want to have a Cat6 system though to future proof things (I gather some HDMI baluns can run on a single Cat6 cable now and 1080p is only viewable via Cat6).

My ideal system would be this:

1) 2 HDMI devices (Sky HD box and another HD satellite box - linked to Astra/Hotbird)
2) 2 TVs in different rooms linked via ethernet cable to the devices
3) The ability to watch either device in each room and control the channels via some kind of IR extender. Also being able to switch between devices from the rooms.
4) (The ability to upgrade the system --- if possible --- and link a 3rd or 4th TV in the future) - this one isn't essential.

Any recommendations on kit/cable etc.?

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