Hi Folk's

After some advise please.

We have just finished building our house, and have a central media cabinet to house all the various gear.

Our electrician has installed an HDMI cable around 20m long to run from the media cabinet to the main tv to transmit the sky signal.

We have just installed sky, and all channels appear fine except for sky sport which can get quite glitchy, upon querying the HDMI cable supplier he advised that the signal may be getting lost due to the length of the cable.

My thinking is, is if all other channels are fine surely the problem would be with the signal itself and and not the HDMI cable.

Any help/comment would be appreciated as the current HDMI runs through the first floor joist space, so impossible to get to in in order to run a shorter cable.

Thanks in advance.