I've recently done some work on a rather large house (13 TV points 2x8 way boosters), and whilst there all the TV's lost signal. The owners then asked me to have a look at the system, and thinking it best to check the incoming signal I removed the aerial input from the first booster and plugged it into a portable TV. I got no signal except for channel 5, which I thought weird. So I went to my van and tried my totally portable TV using it's own aerial. Again only channel 5. Turns out BBC and ITV were down across the Granada area, so the system wasn't at fault.

Now, I didn't install the system, and realise this isn't anywhere near ideal, but the aerial feed comes into the living room just underneath the actual aerial, where it goes into the sky box, then out to the boosters WAYYYYYYYYY on the other side of a massive barn conversion, where the boosters are situated. Then from there out to the 13 TV points

Anyway, long story cut short, I ended up having to replace both boosters, since both had crumbling PCB's. But the new boosters (Again 2x8 way) don't transmit a good signal when all of the TV's are attached. As soon as you connect 5 or more, at least one of the TV's goes all grainy, but the others are spot on.
And, even weirder, the link from the 'Full Out' to the second booster just transmits noise unless you cut out the centre pin! Which I thought, correct me if I'm wrong, is the most important core?????:wonder:

Any ideas on what could be going on, since I can't really leave it like that?

Cheers folks

John:thumb:

A good mate of mine is an aerial man and I've seen a lot of his work.
So based on what I've seen, the original set up sounds far from ideal, but I'm guessing they wanted the Sky feeding to all the TV's?

Anyhoos, have you tried isolating the boosters and/or swapping them over to see if the fault changes? Surely if the fault wasn't there with the "old" boosters then from your post its only the boosters that's different!

Do you have a signal meter?
Can you see if there is a drop in signal strength at the various stages?

Other than that, erm . . . . . erm . . . . do you still have the old boosters?
Try them back on?

do they support the power over coax thingy for magic eye's?

I'm not sure mate. Here's the boosters that are currently installed.
SLx8 8 Way Aerial Amplifier for Satellite TV, Analogue TV and FM (http://www.beststuff.co.uk/slx8.htm)
They're just what my usual wholesaler has in stock.
The old one's just fell apart when the cables were unplugged. Virtually every plug came out with the socket still attached, and a piece of PCB on the back of it!
And yeah, they did want sky distributed, but why they didnt put the boosters a bit closer is beyond me:cuckoo:

Has the Normal terrestrial aerial got a masthead amp on it? or is it direct to sky STB , then out? I assume the 'installer' used a good grade co-ax from sky out to input on Amp? why did the old pcb's crumble? water ingress? would probably have been easier/better to locate the amp/s closer to the uotput of the Sky box due to any loss via the run from output to amp (shouldnt be overly great, but would be a little loss).. connections crimped ?

:lol1: Presume nothing mate, the cable's crap, and the amps were in a cold garage so there's probably been plenty of condensation to rot away the PCB over the years. I'm pretty sure the house was wired by numpties, so the whole lot is probably running right next to high voltage cables. Why take 2 routes when you can jam it all into one eh!:brickwall

Not sure if the aerial has a masthead on however.

yup, see it every working day fella :)

Does anyone have any idea why the 'Full out' link to the second booster only works when ONLY using the outer sheath? If you connect the middle core all you get in the second booster is noise:wonder:

Pass on the problem. But I bet you thought afterwards it was a case of ain't broke don't fix :D

One thing I can say is modern boosters don't seem to be as sensitive/powerful or have as good signal to noise when compared to old fashioned ones. Probably due to the old ones using discreet components (transistors, caps, resistors, coils, etc etc) whilst new ones are IC based. Technically they are supposed to be superior, but as far as I'm concerned, I'm yet to be totally convinced. (Same logic would also explain why my 25year old portable has a far better built in reciever than a 5year old one ;) ).

Bottom line, is what the old ones may be capeable of doing, the new ones might be a bit more picky. I also have to comment on if the customer only "just" noticed the picture was dodgy - seeing you messed with it, its now your fault. When it really was crappy all along just they never noticed or paid full attention to it. I can't tell you how many times I've been at the butt end of that old chesnut. The fact you can't be entirely sure of how good it was in the first place still stands to reason. ;)

Anyhoo, first thing I'd check is any bridgeing between sheilding and the core. Normally at the connector plugs or wall plates.

How are the two boosters wired?...daisy chained or used with a passive splitter from the feed (presumably aerial-->skybox-->boosters). I would suggest its an impedance problem coupled with amplifying unwanted noise. How exactly to combat that is tricky, but using low grade cable, dodgy connections and spanning huge distances will exasperate the issue.

Tell me about it mate. I didn't want to touch it in the first place, but since I'd added an extra TV point in the gym right above the garage that morning, I figured I was going to get the blame no matter what.
I found out later that the problem had occured 30 min's before I'd even been on site, so it was deffinately nothing I'd done. But hey, how often do BBC1, BBC2, ITV and Channel 4 all go off air?!!!! in 27 years I've never seen it happen!
I'm right in the middle of a rock and a hard place. Hopefully when I visit on Friday I'll be able to get something sorted.:wonder:
But yeah, the current order goes
Aerial>Sky Box>Booster 1>Booster 2

Using Booster 1's 'Full Output' to link to booster 2.
There's probably 50-60 meters of cable between the sky box and the first booster, and no way of checking the route, since it's all behind plaster:eek:

fella.. try getting on www.digitalspy or one of the derivatives (sp)?? you may find your answers on there... but agreed with 'sharkman' the *new* amps nowadays are not nearly as good as the older stuff..

I'll give them a whirl in the morning fella, cheers for that:thumb:

no probs, hope you get it sorted without too much more agg... theres nowt worse than having to carry the can when its nowt to do with you .. :(

I would say 50metres between skybox and booster is pushing the limits. I would also suggest checking aerial signal quality as it enters the skybox.

Now, you may want to ignore me on this, as I'm going out of my depth here, so don't start buying more boosters on my account ;):

But if you have a spare booster handy, try it near the skybox with it feeding the other boosters. Now technically, there are reasons why piggy backing lots of boosters is not a brilliant idea, but if it works....;)

Something else to check is if the boosters are providing line power on their input, as this would (well, should) not be needed on the 2nd booster, Come to think of it nor the 1st booster either, unless there is an inline pre-amp/booster hiding somewhere. I don't think it would have any effect, but seeing you are having problems, it maybe the case. And I should add that the premade leads usually supplied with skyboxes and TV etc are rubbish. They'll do for the TVs but between aerial and skybox and skybox and booster I'd think about using something better (can't beat making your own :) ).

Well fellas, I went down there and the signal had deffinately got worse from where I left it. After a bit of messing around I found out that the second booster was causing all the problems, and with it removed the first booster worked fine on all 8 TV outputs and the full output.
That gave me 9 outputs to feed the TV's which is plenty till I can return with a replacement booster, since some of the points in the house are duplicates (There are 3 in the lounge and 2 in the kitchen).
The picture wasn't 100% perfect on all channels, showing a bit of grain on the sky channel especially, but what can you expect when you have soo much cable in the system?:wonder:
At least the 50" plasma in the lounge comes straight off the sky box, so that's perfect.:lol1:

Cheers for all your replies, hopefully this is case closed:thumb:

Grainy picture on the sky TV channel is a PITA...

I've spent a fair few hours trying to sort out our distributed tv system with what maybe a similar proble. Main problem was getting a totally clear frequency channel for the box to work on. BBC2 kept interfering when on the original frequency, and we can pick up 3 seperate TV transmitters in our area (abeilt 2 are weak signals, 1 is strong) , so setting the skybox to use other frequency channels was hit and miss. Video being distributed as well didn't help either. The problem was mainly with the skybox itself not rejecting the interferance on its own frequency channel from the aerial input. Annoying to say the least.

There's a good article here (http://www.kat5.tv/taboo.html) about channel interference.

What I did was to work out (http://www.tvaerials.com/uk_frequencies.aspx) what channels I wanted to keep from the aerial, then bought a band pass filter that covered those, then set the Sky box to outside that range.

I got mine from e Spares (http://www.espares.co.uk/parts?k=bandpass)

To set the Sky output channel, you need to go to the installers menu whuch is hidden, press services then 4 01 Enter and you can set it to whatever you like.