Multiple AV connectivity

[bathjobby]

This setup was done by the engineer when I had a Sat decoder installed;

I have a Sat decoder, DVD recorder and TV connected all using scart sockets and working fine. I also have the TV ariel connected into the RF input on the Sat, Sat RF output to DVD recorder RF in and DVD recorder RF out connected to the TV ariel input socket. All work fine.

Given that the DVD recorder (in addition to the TV) has its own built in TV tuner, I understand why the RF signal goes through that device i.e. to be able to tune to and record terrestial TV progs. Following that logic, I can not immediately see any reason why the RF signal goes to the Sat decoder at all, let alone the first device on its routing.

With regards to the RF (ariel) signal, can I bypass the Sat decoder ? or am I missing something ?

I'm asking before I'm trying as I need a fork lift truck to lift the TV to get to my connections. And in anticipation of the 'if it ain't broke, don't fix it' fraternity, I've got a bit of 'ghosting' on ITV since this set up was put in place and I'm thinking the more devices a signal goes through on it's journey, the weaker it gets.

 

[jtaunton]

Can't see any reason why not, but it may not solve the problem. Ghosting is usuall caused by multiple paths from the transmitter to your aerial.

Say there is a straight line between your TV and the transmitter. If there is a large metal structure somewhere nearby, then another path exist from the transmitter, to the metal object, and then bounced off that to your aerial.

The second signal reaches your TV fractionally later than the original, causing the faint ghost image to the right of the original.

Presumably your DVD recorder must demodulate and then remodulate the signal, so it should be up to strength at the output of that. I guess the Sky Box is just a through path, as the box doesn't actually do anything with the RF, but can't see it having much attenuation.

You could always try pointing your aerial at a different transmitter, if there is one in the area. Or watch terrestrial channels on Sky.

 

[bathjobby]

Thanks for that. I guess 'ghosting' is not strickly true here, more like very faint lines moving slowly across the screen like the 'net curtain' effect (real name for that escapes me right now). Had the problem years ago when trying to get a decent signal until I found right direction for ariel, so know that this terrestrial channel has a weak signal here and the only thing that has changed is adding this extra box. Understand the other (sky) options but trying to keep things simple. I'll get the fork lift truck out and take the RF signal out of the Sat decoder and see what happens.

 

[jtaunton]

Before you get the forklift out, why not try retuning ITV. Don't know where you are, but you may be receiving, lets say, Tyne Tees weakly whilst pointing at the Yorkshire transmitter.

 

[bathjobby]

All good stuff mate, thanks. Tried that though. ITV is my 'compromise' channel so to speak i.e. there is a better signal in a different direction where I am but if I point the ariel in that direction, then I almost loose the other channels. So where I'm pointed I have the best BBC reception with 'OK' ITV, until just now were it is just below 'OK' with the faint lines. So will try taking out the extra box (sky) in the RF link and see what happens. Another thought I guess is that I see no reason either for trying and having 2 ariels connected together, one pointing to my current BBC trans and the second pointing off towards the better ITV trans ! unless that really does give me 'ghosting' ! Um, warm up the fork lift.......