Signal Attenuation

G

grasmith

Member
My Satellite Setup
Freesat via Sony KDL-40w5810 TV
HP Pavilion 2GHz Notebook
My Location
Sunderland UK
Hi Folks

I have Freesat via Sony KDL-40W5810 TV. The cable feed from S/dish to TV is straight through the wall to the set, i.e no break. The signal strength is excellent.

What I really want to do is cable the TV in much the same way as it is cabled for UHF reception i.e via a wall-plate (with F-connector,of course). My question is - in cutting the cable, and creating 2 more connection points at the wall-plate (back of wall-plate; flying lead to TV F-connector) will there be a significant attenuation of sig' strength that might cause viewing problems?

Thanks.
 
Welcome to the forum grasmith.

From a technical point of view, the signal will be attenuated by around <2dB. Practically, this won't effect signal quality on a medium /short run so no cause for concern :)
 
If you use an F-barrel connector, and a wall plate with the guts ripped out, you certainly won't have a problem.

Some poor quality wall plates, or ones that have been poorly installed can cause problems.
 
And there are plenty of badly designed wall-plates out there.


Best advice is leave it as it is, but if you really are determined, use a deep back box so the incoming cable remains unkinked.
 
Thanks for both replies.

What concentrates the mind, in respect of my question, is that once the cable is cut there is no going back - except for a new and expensive cable run! Hey-Ho.
 
Well either that, or open up the hole on the room side to about 30mm, get a blank wall plate, long Female to female "F" adapter drill the plate and fit the connector. Then connect direct to the back with the incoming cable, waterproof with self amalgamating tape and screw the plate direct to the wall with small chromed screws. Works a treat and looks better than a surface mount.

A single join in the cable makes next to no difference at all, so don't worry.
 
While a join will have no practical effect on Strength, you need to ensure that screening is maintained at the join.

As Robbo indicates, if you go the Wallplate route, avoid poor quality examples and ensure you get one which is "fully screened" throughout.

The reason is that degradation of screening can provided loss of immunity to interference in the Intermediate Frequencies sent along the cable, and in particular can lead to problems with DECT phone interference at around 1.88 GHz.

Should this occur, you might get poor results on Channels originating from around 11630 MHz and around 12480 MHz.
 
And what I should have added to the last sentence in my above post is the word quality, should have read "A single (quality) join in the cable makes next to no difference at all, so don't worry." which makes more sense.:)
 
rolfw said:
And what I should have added to the last sentence in my above post is the word quality, should have read "A single (quality) join in the cable makes next to no difference at all, so don't worry." which makes more sense.:)
Click to expand...

A quality electrician's join (bare, twist and tape) should be avoided though ;)
 
Stout fellow(s) :cool: :)

One man's quality is another man's cause for opprobrium and apoplexy.
 
Quality Triax F Connector single screened module would suit.
 

Attachments

  • traix plate.satsukSM.webp
    traix plate.satsukSM.webp
    6.3 KB · Views: 34
Thanks to all contributors to this thread.

On the basis of the discussion so far, and the likely-hood of making a right royal mess of chasing holes in walls (I forgot to mention that there is also a twin cable, for future use, entering at the same point), I will most probably leave things as they are. Anybody got an idea how I could tidy up the cable entry point into the room?
 
For two cables you could use for example item No. 304264 (attached).
A surface pattress box wouldn't require chasing in, just two small screws for fixing.

Take a browse for a detailed list of plates. _http://www.triax.co.uk/upload/outlets.pdf
 

Attachments

  • quad plate.satsukSM.webp
    quad plate.satsukSM.webp
    3.1 KB · Views: 24
grasmith said:
Anybody got an idea how I could tidy up the cable entry point into the room?
Click to expand...

Yes, you could use 2 single cable entry hole tidys or grommet, or a double one if you can get hold of. Should be able to pick up on ebay.
 
Or one of these: _http://clearvisionsystems.co.uk/onlineshop/installation/brush-wall-plates/brush-faceplate-white-single-gang/prod_272.html
 
Back
Top