Saorview/Freesat Using same loft wiring

Spn744

Hoping someone can help with the issue I’m having.

Aerial and satellite are split down to the sitting room using a TV/Sat splitter (using the same wire) they both receive a signal but the issue I am having is that I can only use the Saorview is when the satellite box is completely unplugged from the wall otherwise it says “no signal”

From what I can see online there’s something about one being the master connection and knocking off the other when both are pulling for signal.

I am using a sky q LNB and some suggest changing to the old sky hd LNB as this won’t pull as much power and should allow a joint connection.

Any help would be much appreciated, above was completed by a satellite company and may have to bring them back out if the issue isn’t easily fixed.

Elvis Hammond

Are you sure it's a proper terrestrial/satellite splitter (diplexer) you have?

Spn744

Elvis Hammond wrote: »

Are you sure it's a proper terrestrial/satellite splitter (diplexer) you have?

This is the exact one I have https://www.aerialsandtv.com/product/diplexer-internal-terr-satellite-cw-f-connector

Thanks

Elvis Hammond

If the signals from dish & aerial are combined with one of those, any interference from the LNB in the terrestrial frequencies should be greatly reduced. So if it's definitely a diplexer like that in the attic, the Saorview signal must just be very poor to begin with.

These diplexers aren't compatible with wideband LNBs, like the Sky one in non-legacy mode, which is why I wondered if some kind of bodge had been done with an unfiltered splitter.

Spn744

Elvis Hammond wrote: »

If the signals from dish & aerial are combined with one of those, any interference from the LNB in the terrestrial frequencies should be greatly reduced. So if it's definitely a diplexer like that in the attic, the Saorview signal must just be very poor to begin with.

These diplexers aren't compatible with wideband LNBs, like the Sky one in non-legacy mode, which is why I wondered if some kind of bodge had been done with an unfiltered splitter.

They’re connected up with a wideband LNB thats 100% the case. Both connected but Saorview only works if the sky box is off at the wall. Do you think if I change it to a standard sky HD LNB the issue might resolve? Saorview signal brilliant when working so I don’t think it’s a signal issue. Appreciate the help.

UrbanFret

Do you have another splitter in the sitting room to split them back out?

Elvis Hammond

Spn744 wrote: »

They’re connected up with a wideband LNB thats 100% the case. Both connected but Saorview only works if the sky box is off at the wall. Do you think if I change it to a standard sky HD LNB the issue might resolve? Saorview signal brilliant when working so I don’t think it’s a signal issue. Appreciate the help.

What kind of satellite receiver do you have? (It ways Sky in the quoted post & Freesat in the OP.) If it's expecting a wideband signal from a non-hybrid LNB, that diplexer will be blocking some of the frequencies it needs.

atilladehun

Not much help other than I have the same problem. Mine come on separate cables but can't watch saorview without turning freesat box off at the wall.

Elvis Hammond

UrbanFret wrote: »

Do you have another splitter in the sitting room to split them back out?

It doesn't matter as much if the diplexer type is used at the receiver end. Signal levels will be better with the diplexer though.

Spn744

UrbanFret wrote: »

Do you have another splitter in the sitting room to split them back out?

Yes the exact same one in the loft as the sitting room

Spn744

Elvis Hammond wrote: »

What kind of satellite receiver do you have? (It ways Sky in the quoted post & Freesat in the OP.) If it's expecting a wideband signal from a non-hybrid LNB, that diplexer will be blocking some of the frequencies it needs.

It’s currently connected to a sky Q box, got the aerial installed in anticipation of cancelling sky next month and then I have bought a freesat 4K box (arris) that I’ll have by the end of the week which was suppose to replace the sky set up as it accepts the new LNB. I’ll have to get the satellite people back out I just need to know what’s the best thing to do going forward

Glaceon

Terrestrial/satellite diplexers don’t work with wideband LNBs, only the more traditional types. The wideband LNBs will output on frequencies as low as 350 MHz and therefore interfere with the terrestrial signal. Other LNBs output at 950 MHz and higher and this is what allows the signals to be combined.

Spn744

atilladehun wrote: »

Not much help other than I have the same problem. Mine come on separate cables but can't watch saorview without turning freesat box off at the wall.

Which LNB do you have? Thanks

Spn744

Glaceon wrote: »

Terrestrial/satellite diplexers don’t work with wideband LNBs, only the more traditional types. The wideband LNBs will output on frequencies as low as 350 MHz and therefore interfere with the terrestrial signal. Other LNBs output at 950 MHz and higher and this is what allows the signals to be combined.

So you would be confident if I switched to the old style LNB this should resolve the issue? Appreciate the response.

Elvis Hammond

Spn744 wrote: »

It’s currently connected to a sky Q box, got the aerial installed in anticipation of cancelling sky next month and then I have bought a freesat 4K box (arris) that I’ll have by the end of the week which was suppose to replace the sky set up as it accepts the new LNB. I’ll have to get the satellite people back out I just need to know what’s the best thing to do going forward

Well, terrestrial TV & wideband LNBs don't mix, & I suppose a dedicated cable for terrestrial would make sense. I assume there are also other frequency-shifting options, like unicable/SCR.

That said, I would have expected Saorview to work with the present setup, unless the output of the LNB is overwhelming the diplexer filtering, or the Saorview signal is borderline to begin with. Or the Sky box itself might just be causing interference closer to the TV.

Glaceon

Spn744 wrote: »

So you would be confident if I switched to the old style LNB this should resolve the issue? Appreciate the response.

Absolutely. The intermediate frequency (IF) on wideband LNBs is around 300 to 2350 MHz. The Saorview channels are between 470 and 690 MHz which is within the IF range of the wideband LNB. The IF on regular (universal) LNBs is 950 to 2150 MHz, so the Saorview frequencies are left alone.

Spn744

Thanks for everyone’s replies, I think I have all the info I need and will update the post later in the week to let you know how I get on appreciate the help!

Elvis Hammond

Glaceon wrote: »

Absolutely. The intermediate frequency (IF) on wideband LNBs is around 300 to 2350 MHz. The Saorview channels are between 470 and 690 MHz which is within the IF range of the wideband LNB. The IF on regular (universal) LNBs is 950 to 2150 MHz, so the Saorview frequencies are left alone.

You realise the sat./terr. diplexer is supposed to filter anything below 950MHz on the sat. input, so Saorview should be 'left alone' with the wideband LNB too?

The diplexers at least seem to cope alright with any spurious terrestrial band output from universal LNBs.

Glaceon

Elvis Hammond wrote: »

You realise the sat./terr. diplexer is supposed to filter anything below 950MHz on the sat. input, so Saorview should be 'left alone' with the wideband LNB too?

The diplexers at least seem to cope alright with any spurious terrestrial band output from universal LNBs.

The problem there is that it would filter out any satellite channels in the sub 950 MHz range. You’d end up losing a lot of channels on whatever polarity you fed the terrestrial signal into. The point of wideband LNBs is to shift down the entire band.

Elvis Hammond

Glaceon wrote: »

The problem there is that it would filter out any satellite channels in the sub 950 MHz range. You’d end up losing a lot of channels on whatever polarity you fed the terrestrial signal into ...

Yes, I mentioned that already myself. It doesn't explain why Saorview doesn't work with the current setup though, unless the diplexer just can't handle the LNB output, compared to what it would have to filter out for a 'universal' LNB.

Glaceon

Let's do some investigative work here.

The local oscillator on a Sky Q wideband LNB is 10.41 GHz and uses one cable for vertically polarised frequencies and a second one for horizontally polarised frequencies. Let's say you're picking up Saorview from Woodcock Hill on channels 44 and 47, which are 658 and 682 MHz. Transponder 64 (11.068 V), which contains some ITV HD regions, would be downconverted by the LNB to 658 MHz and directly interfere with the Saorview signal on channel 44 if you happened to have the diplexer attached to the vertical feed from the LNB. Chances are that the channels on that transponder are also wiped out.

Spn744

Just to note to the above discussion Rte One, +1 and Saorview information work at the same time as the satellite feed. A few of the radios might as well but can check when home the rest don’t work unless the satellite box is completely unplugged.

Elvis Hammond

Glaceon wrote: »

Let's do some investigative work here.

The local oscillator on a Sky Q wideband LNB is 10.41 GHz and uses one cable for vertically polarised frequencies and a second one for horizontally polarised frequencies. Let's say you're picking up Saorview from Woodcock Hill on channels 44 and 47, which are 658 and 682 MHz. Transponder 64 (11.068 V), which contains some ITV HD regions, would be downconverted by the LNB to 658 MHz and directly interfere with the Saorview signal on channel 44 if you happened to have the diplexer attached to the vertical feed from the LNB.

You know what a diplexer actually does, right? Why do you think the sat. input is letting through enough signal below its supposed cutoff point, to cause interference to Saorview?

Glaceon

Sounds to me like you don’t understand it. You’re feeding two signals at the same frequency down the same wire. You can’t separate them once combined, you’ll end up with garbage on both feeds even after splitting the cable on the receiver end. The only way this would work is if your diplexer downshifted the frequency of the Saorview signal below 300 MHz before combining it with the satellite signal.

In my example above, even if one of the feeds was filtered out, you’d lose the ITV HD channels or the Saorview mux. You can’t have both.

Elvis Hammond

Glaceon wrote: »

Sounds to me like you don’t understand it. You’re feeding two signals at the same frequency down the same wire. You can’t separate them once combined, you’ll end up with garbage on both feeds even after splitting the cable on the receiver end ...

The satellite input on the diplexer is supposed to filter out anything below 950MHz. One of the main points of a diplexer is that you avoid 'feeding two signals at the same frequency down the same wire'.

Universal LNBs produce spurious crap on terrestrial freqs., that needs to be filtered out.

Glaceon

Elvis Hammond wrote: »

The satellite input on the diplexer is supposed to filter out anything below 950MHz. One of the main points of a diplexer is that you avoid 'feeding two signals at the same frequency down the same wire'.

Universal LNBs produce spurious crap on terrestrial freqs., that needs to be filtered out.

That’s fine for a universal LNB but not for a wideband, which needs the extra frequency space below 950 MHz. If the satellite input filtered out anything below 950 that’s a lot of satellite channels you’ll lose. If your LNB has downconverted something to 658 MHz and your aerial also receives something at 658 MHz, how else could it work unless your diplexer downconverted the Saorview signal too?

Elvis Hammond

Glaceon wrote: »

That’s fine for a universal LNB but not for a wideband, which needs the extra frequency space below 950 MHz. If the satellite input filtered out anything below 950 that’s a lot of satellite channels you’ll lose. If your LNB has downconverted something to 658 MHz and your aerial also receives something at 658 MHz, how else could it work unless your diplexer downconverted the Saorview signal too?

Obviously the OP is missing some satellite channels with the setup as it is. The question they asked though is why Saorview isn't working unless the Sky box is switched off.

Glaceon

Forget about it, I’m done here.

Elvis Hammond

Spn744 wrote: »

Just to note to the above discussion Rte One, +1 and Saorview information work at the same time as the satellite feed. A few of the radios might as well but can check when home the rest don’t work unless the satellite box is completely unplugged.

That multiplex (mux 2), must either have a better signal than mux 1 (RTE2, TG4 ... ) to begin with, or it's less impacted by the interference.

Where is the Saorview aerial installed?

Spn744

Elvis Hammond wrote: »

That multiplex (mux 2), must either have a better signal than mux 1 (RTE2, TG4 ... ) to begin with, or it's less impacted by the interference.

Where is the Saorview aerial installed?

Aerial is in the loft - Satellite on an outside wall

Elvis Hammond

Spn744 wrote: »

Aerial is in the loft ...

I wonder was this purely for installer convenience or is it providing a good healthy signal. If it's the former, then poor signal could be at the root of the problem, & it could still be troublesome even if changing the LNB helps out interference-wise.