No visual cable damage but a connection anomaly. Wolsey WFAV 425 4 way distribution amplifier and PSU.
Lots of coax arriving and departing from attic but to an agricultural eye the aerial and distribution amplifier seem cross connected. What I think is the aerial goes to TV on the PSU and IN goes to the distributor.
Can you enlighten me?
If it has been working and since died and the connections not changed then I would say yes, either the amp or it's PSU have died. ;-(
Ok
I can try.
Aerial goes to the 'In' on the mast head end / splitter bit.
Any output of the splitter amp goes to in of the PSU, or just one, depending on the markings on the masthead bit (DC though etc).
The output on the PSU goes to a TV, as do any unused outputs on the masthead / splitter / amp.
I think the idea is that the PSU feeds power to the masthead amp *and* the PSU either has it's own amp built in (as well) or it can control the gain on the masthead part remotely?
Either way I believe the interconnections to be the same.
Cheers, T i m
I forgot to add, assuming the masthead bit is in the loft (or you have easy access to it) and assuming you have sufficiently good signal where you are, you might be able to test the PSU part separately by putting the aerial directly into the PSU.
Don't do so till that has been qualified as I'm not sure if you would need to disable the PSU power output (switch?) when it's fed directly to the aerial?
If that's ok it should prove the signal path through the PSU to be ok or not. I think you should also be able to read a voltage (12V DC?) from the 'In' port.
Variables apply etc. ;-)
Cheers, T i m
From:
I would recheck the aerial goes to the input. Are you haunted by an unknown presence who enjoys moving cables around?
Though most likely the PSU has failed, I presume it's a 12V wall wort or similar?
Any of the signal outputs will accept 12V from the PSU. So the PSU should be along one of the feeders that take signal from any of the OUT sockets on the main unit to the TV sets. The PSU should be connected with 'TV' going to the TV set and 'IN' going to the main unit.
Bill
There's various routines to diagnose the fault, once you've made sure that everything is connected properly and that mains power is present at the PSU.
I hope you're taking your muddy wellies off before going into the house.
Bill
That would suggest there is power getting to the PSU and possibly available in the box somewhere, not that it's actually getting out of the unit.
Multimeter should do. 20V DC range and put on the 'IN' port of the PSU. It doesn't matter which way round you put the leads, just one on the outer thread and one down the middle (you might need a piece of wire if your probe is too thick). I believe you should see something like 12V DC. If you don't, it would suggest the PSU is faulty, if it do and it's also at the feed from the PSU to one of the mast head output ports (and no wiring has changed and no TV works anywhere), then it's likely the masthead box itself.
Cheers, T i m
Correct ... (but in your case, one would go via the PSU).
I don't think so. Remember it's primarily a PSU to power the distribution part of the masthead box (over having a passive splitter) and it get's it's power by being fed up the cable from the PSU whilst also feeding TV signals back down the same lead.
You could take that PSU away and power the amplifier from one of your TV's or STB's etc.
Do you have more than one aerial cable coming from the aerial (area) itself Tim?
Then are you sure both bits aren't in the loft?
Cheers, T i m
You built a new property without a 'boot room' ???
In message , T i m writes
OK. 12VDC at PSU.
Still no visible mast head box but I suppose it could be tucked under the tiles.
I'll drag out a ladder. *F* connectors so loose joint unlikely.
There is no visible mast head amplifier. I assume these are never built into the aerial itself?
12V DC at PSU. Trying to anticipate the *various routines*, I tried coupling what I now think is the aerial directly to the PSU and then tried each of the TV links in turn as I don't know which feeds the nearest TV. Nothing of interest found.Luckily her Humax is more tolerant of a weak signal and she can watch channels 1 to 5 through that.
Is it common practice to tuck the mast head amplifier under the tiles? New cables were fitted so tiles have been off.
Late thought.. what happens if a TV mast head supply is switched on as well?
Fuba did that.
Didn't the huge Televes ones have an optional "Margin Raising Device"?
Recent thunderstorms?? Brian
Surely, if the psu is meant to feed voltage up the cable it has to be short circuit proof, ie if the aerial was plugged into the psu where the amp distribution box was it should work on that downleead but at a lower signal level. If its non existant, then there could be another amp I guess. Back in the mists of time I had a little home made lead with a capacitor in series with the inner. If I inserted it and the signal was hugely low then the amp must be doing something when it was powered. Otherwise it means the dist amp is knackered. Bit odd for it to die so fast even the old Antiference ones lasted nearly a year. grin. Brian
On the 'In' or whatever the opposite of the Out / TV connection? Ok, well that looks good then (at least off load).
Any sign of the other TV feeds though Tim? They should all converge somewhere, either in the loft out outside somewhere.
No, but sometimes people can forget to fully tighten them or if the mast head box (that doesn't have to be at the mast head) isn't upright and water has got into it ...
The reason the put them at the 'mast head' hear the aerial is so that you have the best signal and the lowest noise before you amplify both and send it round the house.
However, with good quality cable (copper, foil sheathed), a fairly good signal (you should be in the 'good' signal area for CP?), the aerial 10m off the ground and pointing the right way, and the right aerial (Group A, 10db gain or better) you should have enough signal to get a good signal to noise ratio to be able to have the distribution-amp (and PSU) in the loft. This gives several advantages:
1) You don't have any electronics outside (weathering) 2) You don't have anything that might need maintenance, outside and up a pole (difficult access). 3) You only need one cable from the aerial to inside the loft. (Simplicity) 4) You can get to all the bits that can go wrong easily (easy access). 5) You can easily test / mix / match / replace all the fallible bits. (Easy repair)So, assuming you can find the mast head / distribution amp bit, you could remove the end of the cable that comes from the PSU and check for your 12V there. If it is and everything else looks ok (aerial still in place and still facing the right way, cables all good etc) then I think you are looking at a dead amp (the most likely under the circumstances and from the symptoms and results of your tests so far).
I think that would be a reasonable point to give your installer a call and see what he suggests is done next.
Any chance of a link to the actual kit you think you have there Tim?
Is it this (when you find it). ;-)
Cheers, T i m
Whilst they could be, I don't think I've ever seen one. I think it would make the whole thing quite inflexible, given that you may or may not want that specific amp on that specific aerial so probably would sell other than in very specific scenarios.
It's all pointing to a dead distribution amp then Tim. ;-(
So you are obviously getting *something* at the end of the wire? And when you say ' 1 to 5', you mean they are all A want's to watch so is happy? BBC1 and BBC2 are on the PSB1 Mux, ITV, C4 and C5 on PSB2, so you are getting at least 2 muxes. ;-)
Only if it is still reasonably accessible afterwards?
Ok.
On some downstairs gear you mean, like a Humax STB?
I think it would just be ignored by your loft PSU but could mean that it could cover the PSU role, in the event of it failing (by just bypassing the PSU and joining the two cables together).
Any chance seeing where the cables to / from the outlets converge in the loft Tim? Or are you saying they go up over any felt / roof lining and under the tiles and from different entry points?
Could you give your installer a ring and see if he remembers where he left it?
Cheers, T i m
And triax did that with their DAT45 and DAT75 but it was called a "MRD" Margin Raising Device and did require DC line power....
You have now
There's a relay, so with no power it's simply by-passed
I can see I am going to need a photo!
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.