Question Can't get my Antiference multi-switch system to output SKY Satellite signal

wp73

Novice Member
Hi,
We just moved into a new house and it has a preinstalled satellite multi-switch distribution system in the loft, it is an Antiference quad/quattro LNB iSYS7 model (5 inputs, 4x sat, 1x aerial) and 16 outputs. Every room in the house has a satellite wall plate however these are all female co-axial sockets. My question is do I need a diplexer/triplexer to correctly feed the satellite signal into the SKY boxes in each room? The only room I can get working with a freeview box is the one where the faceplate is a triplex plate i.e., it separates back out the TV and satellite and FM feeds. I should point out that I am only feeding the satellite dish into the multi-switch (no aerial signal or FM is fed), so my question is, do I still need a di/triplexer do get the satellite signal coming out of the female coaxial socket on the wall plate (i.e., do I need to replace all these sockets with triplex wall plates?). I would have hoped that if I only feed satellite into the multi-switch, I can get satellite back out without a diplexer since the signal never got combined with anything, or does the multi-switch do something else? I have setup the SKY boxes to work from just one line feed as required and I am using a normal coaxial cable to connect the wall plate to the SKY box.
Thank you
WP
 

Rodders53

Distinguished Member
Antiference quad/quattro LNB iSYS7 model (5 inputs, 4x sat, 1x aerial) and 16 outputs.
All the units I can find have UHF/DAB/FM inputs plus 4 lnb making it 7 inputs... but..
Every room in the house has a satellite wall plate however these are all female co-axial sockets.
F- sockets (screw thread style)? Or standard UHF TV type (Belling Lee)?
My question is do I need a diplexer/triplexer to correctly feed the satellite signal into the SKY boxes in each room?
No. Not if the socket's cable goes to one of the iSYS outputs and is correctly wired/terminated for satellite.
The only room I can get working with a freeview box is the one where the faceplate is a triplex plate i.e., it separates back out the TV and satellite and FM feeds.
:confused:Freeview is via a UHF terrestrial aerial. Do you mean 'Free Sat from Sky' perhaps? (as you state you have no aerial connected).
I am using a normal coaxial cable to connect the wall plate to the SKY box.
Do you mean a 'normal satellite cable' with F-plugs on each end or something else? (If unsure attaching a photo will help us to identify?)

The most likely reason that the $ky boxes do not get a signal is a mis-connection or lack of DC continuity in the cabling... Whether by inserting the F-plugs wrongly or a wallplate having a DC blocking effect* if Belling Lee isolating plates have been installed or some other problem such as a break in the cable. {NB handmade Belling Lee TV plugs can easily have no DC continuity, but still pass RF frequencies.} {* photos of both front and back (removed from wall) of a non-working wallplate would also be useful.}

That the $ky boxes work on one circuit with the filtered wallplate would suggest the system works... when properly terminated and connected. So we're looking for the reason why others do not.
 

wp73

Novice Member
Yes 7 inputs, although I only have 5 cables available to me, 4x satellite and 1x aerial, only satellite cables are connected.
UHF aerial type faceplates - i have been using an adaptor to get them to the F type socket on the SKY box
Free Sat was what I meant. Thanks for taking the time to help. I will try to take some pictures and come back.
 

Rodders53

Distinguished Member
I strongly suspect isolated wallplates will have been fitted. No idea why. These have a capacitor inline to stop DC passing. Ditch them all asap. Belling Lee connectors are not at all suitable for satellite signals and will give you problems sooner or later, anyway. Likely they are unscreened plates so not really suitable for UHF TV either.

Wall Plates face plates screened sockets and Satellite, Television, FM, DAB, Aerial, Coaxial Cable, Plugs, Sockets, Connectors & Leads are both worth a read through.

You could opt for triplex type plates to allow for a UHF and FM/DAB aerial addition over time... or just a single f-connector (which will be only slightly cheaper). Do use screened wallplates, or a cable joiner with f-plugs to maintain screening, though.
 

wp73

Novice Member
upload_2016-12-31_9-21-54.png


I managed to check a few sockets, some are properly shielded others are not. I actually managed to get some of the TV points working with freesat by playing around with the various cables the loft that attach to the outputs of the Antiference multi-switch. On several TV points however the SKY box builds the planner but still has no signal. The time updates so I know it's connected to the satellite, but no picture. I ensured that the box is setup to receive one cable only in settings. Any advice on this? Could it still be a bad connection?
Thank you
WP

Here is the outside of the socket as requested.
 

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Rodders53

Distinguished Member
That screened TV socket # 304124 is probably made by Triax, but is not a current product? Unlikely to be DC blocking - but I can't be sure as the part number doesn't google... Triax - Product Search{55310DE9-DD0F-47CC-8059-94C015A713C9}
Triax are good, so those ones may be worth retaining (or selling on)?

I suspect your TV to F plug converter cables may not be making a good DC path so not sending the correct signals to the iSYS7 ?
Low-noise block downconverter - Wikipedia

The centre pin on a Belling Lee plug needs soldering , crimping or a screw connection to ensure DC continuity... although the kinky centre core method can sometimes work as well - after a fashion (but may not be reliable).

I don't know if the iSYS7 squirts out one of the four LNB inputs in the presence of no 'request' signal... or which one if it did. Should it do so and if it were the default transponder for $ky (High band 11.778 GHz, Vertical (13V=V, 22kHz=High)) other transponders in the same High, Vertical band would include TV programmes (in the clear) from:
Viva UK, Yesterday, Drama, Really, Sky News, Pick TV, Pick TV+1 and Community Channel. So not very many to give a signal if the iSYS7 isn't switching any other LNB input to the attached receiver... I don't know the $ky EPG LCNs for any of them though. {A large number of encrypted $ky channels are also on High, V transponders}.

The installation menu should also give access to a signal level quality meter?

Note that the $ky intermediate frequency signals from the LNBs at are in excess of 950MHz and the Belling Lee socket is only quoted for working up to 890MHz ... they could have very strange impedance mismatching and increased losses at the satellite intermediate frequencies used. So do plan to replace them with F-plugs and sockets in the long term!
 

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