Signal to STB weaker with HDMI lead than with Scart!

Digifriendly

I was visiting a friend yesterday and he had a Freeview HD STB connected to his HD ready TV via a scart lead. I told him that to receive proper HD pictures he needed an HDMI lead instead of a scart. He duly produced an HDMI lead which I fitted instead of the scart. I noticed that there was breakup occurring on certain channels that were working fine with the scart lead connected. I checked the aerial connections and everything seemed OK. Can anyone explain why the signal would be weaker with HDMI than with scart? I read on another forum that if an HDMI cable is touching an aerial cable the signal can be affected. Could this be causing the problem? Help greatly appreciated.

Atlantic Dawn

Did you try switch back to Scart after to see if the problem resolved? I would think either the install of the HDMI lead unsettled the cable from the aerial or else perhaps a problem with the HDMI cable itself.

bridster007

Interference from hdmi cable to aerial cable and vice versa is well known. They don't even have to be touching for the problem.
Try a different hdmi cable, just a cheapie is likely to be as good as a pricy one.
I have the same problem whenever my cables come within close contact. The cables need good screening.

Antenna

Try HDMI cables which pass through ferrite cores near each end.

you can see what I mean here:

http://www.maplin.ie/p/maplin-hdmi-cable-15m-a10nt

unfortunately your HDMI cable is radiating interference at UHF (especially the lower channels) and the ferrite cores are there to suppress this.

Better screened aerial cables help too , and make sure the coax outer on aerial plugs is making good contact (to keep nearby interference out)

You can get clamp-on ferrite cores to clamp on to existing HDMI cables too (close to each end)

If you have an unshielded aerial wall-plate keep all other cables (apart from aerial cable) away from it as much as possible and ferrites on the aerial cable too can help..

bridster007

Antenna wrote: »

Try HDMI cables which pass through ferrite cores near each end.

you can see what I mean here:

http://www.maplin.ie/p/maplin-hdmi-cable-15m-a10nt

unfortunately your HDMI cable is radiating interference at UHF (especially the lower channels) and the ferrite cores are there to suppress this.

Better screened aerial cables help too , and make sure the coax outer on aerial plugs is making good contact (to keep nearby interference out)

You can get clamp-on ferrite cores to clamp on to existing HDMI cables too (close to each end)

If you have an unshielded aerial wall-plate keep all other cables (apart from aerial cable) away from it as much as possible and ferrites on the aerial cable too can help..

I wouldn't spend that sort of money on hdmi cables with no guarantee it would solve the problem. Just try a different standard cbale and keep cables apart.

Digifriendly

Many thanks for all the help. Managed to separate HDMI cable from touching aerial cable and that improved the signal to point of no breakup.

Antenna

bridster007 wrote: »

I wouldn't spend that sort of money on hdmi cables with no guarantee it would solve the problem. Just try a different standard cbale and keep cables apart.

I wasn't advocating purchase of that particular cable (at that price) , I was just using the picture of it to show what I meant by cables with ferrite cores - cheaper cables with them are available. (I should have made this clear) The ferrite cores help block interference flowing on the outside of the cable shield due to any poor shielding of the sockets/devices at the end (s) of the cable.

There are certainly a lot of junk aerial leads out there too which easily let in interference from nearby cables/devices.

See the attached pictures of a bargain aerial Coax Cable about 1.5 meters in length with Male, Female plugs at the ends (as used to connect a VCR/skybox etc to a TV etc) which was bought some years ago from a branch of what was the "4Home Superstores" but left in storage and not tried until the other day.
This was 'Made In China' by an obscure brand I never heard before called "JIN FAN", though the same thing was probably sold under other names too.

I tried using it between an FM tuner and an aerial wall socket (which was connected to an attic aerial) when tuned to a lower strength station. There was significant deterioration of reception compared with a decent cable ! And this at VHF Band II, not to mind talking about UHF!

It being worthless I cut the cable to see how bad the screening was (see picture)!