What Distribution Amplifier - Sky&Freeview

[Lucid]

Are you talking about Freeview reception in total, or trying to get the RF2 out signal from the Sky box?


Alexandra Palace muxes - 31, 32, 37

Crystal Palace muxes - 22, 23, 25, 26, 28, 30
Crystal Palace local mux - 35


When you say you get nothing from ch 50-68, if we're talking Freeview then that's no surprise. Those channels are blocked off for mobile phone use.

If you mean for the Sky RF out, then the issue is the RF amp you have. It has this LTE 700 feature. That means the amp filters out ch49~68. Any signals from the aerial in that range are blocked by the amp so that they don't make it to the 1~8 outputs. The amp can only pass signals in the ch21~48 range. (This also renders your separate LTE filter redundant too.)

Here's the info from the horse's mouth. This is a screen grab from the Triax/Wolsey website for that amp. Read where it says Output frequency range MHz

If you bought the amp from the TradeWorks site, then their information is incorrect. Here's a screen grab for the tech specs from that site. They show the UHF (TV) frequency range as 470~790MHz. That's the ch 21~59 range after the 800MHz clearance.

What's happened then is that the Wolsey amp spec has changed, but the retailer either wasn't made aware or they didn't understand the significance of that change. Whatever the reason, the upshot is that they never updated the info on their own product listing.


You have a get-out here because of their mistake. It is possible for you to say you needed an amp that goes higher than ch48 @ 690MHz, and their tech specs says the amp goes to 790MHz but you have found that it doesn't. For this reason, it's not as described and so not suitable.

If they counter by saying that 'LTE' is shown (and I don't think they will), you can reply that you don't know what they mean by that. There are different versions of LTE and their listing hasn't made it clear which LTE standard applies. However, their frequency spec suggests that the amp is LTE 800 protected. This would have been fine, but it turns out that their info is wrong. I would recommend that you take screen grabs of the page as insurance.

That still leaves you with the task of finding an 8-way variable amp that's either the old 490-850MHz range (ch21~68) or a true LTE800 amp which means you have from channels 49~59 available for the Sky RF2 output.

The wiring would then use your LTE 700 filter as follows.

 

[rossyl]

Are you talking about Freeview reception in total, or trying to get the RF2 out signal from the Sky box?


Alexandra Palace muxes - 31, 32, 37

Crystal Palace muxes - 22, 23, 25, 26, 28, 30
Crystal Palace local mux - 35


When you say you get nothing from ch 50-68, if we're talking Freeview then that's no surprise. Those channels are blocked off for mobile phone use.

If you mean for the Sky RF out, then the issue is the RF amp you have. It has this LTE 700 feature. That means the amp filters out ch49~68. Any signals from the aerial in that range are blocked by the amp so that they don't make it to the 1~8 outputs. The amp can only pass signals in the ch21~48 range. (This also renders your separate LTE filter redundant too.)

Here's the info from the horse's mouth. This is a screen grab from the Triax/Wolsey website for that amp. Read where it says Output frequency range MHz

View attachment 337625

If you bought the amp from the TradeWorks site, then their information is incorrect. Here's a screen grab for the tech specs from that site. They show the UHF (TV) frequency range as 470~790MHz. That's the ch 21~59 range after the 800MHz clearance.

View attachment 337628

What's happened then is that the Wolsey amp spec has changed, but the retailer either wasn't made aware or they didn't understand the significance of that change. Whatever the reason, the upshot is that they never updated the info on their own product listing.


You have a get-out here because of their mistake. It is possible for you to say you needed an amp that goes higher than ch48 @ 690MHz, and their tech specs says the amp goes to 790MHz but you have found that it doesn't. For this reason, it's not as described and so not suitable.

If they counter by saying that 'LTE' is shown (and I don't think they will), you can reply that you don't know what they mean by that. There are different versions of LTE and their listing hasn't made it clear which LTE standard applies. However, their frequency spec suggests that the amp is LTE 800 protected. This would have been fine, but it turns out that their info is wrong. I would recommend that you take screen grabs of the page as insurance.

That still leaves you with the task of finding an 8-way variable amp that's either the old 490-850MHz range (ch21~68) or a true LTE800 amp which means you have from channels 49~59 available for the Sky RF2 output.

The wiring would then use your LTE 700 filter as follows.

View attachment 337632

Lucid, thank you so much for coming back to me and the comprehensive response. Much appreciated.

The Distribution Amplifier has two inputs
1. Freeview
2. Sky RF Out.

The Freeview signal is perfect.
The Sky RF Out is the one that is fuzzy.

Thanks for your research, helps me understand the issue.

So, it appears that the Distribution Amplifier by blocking CH49-CH68 the result is that I cannot use a LTE filter.

Couple of questions, please

1. On your diagram above, why would I only need an LTE filter on the Freeview signal but not the Sky RF Out, before plugging into a 'Full Range' (non filtered) Distribution Amplifier?

2. I am a little confused as to how the LTE800 distribution Amplifier would solve the issue?
Frequency range UHF 470-790 MHz
Frequency range DAB 217-230 MHz

This one appears to fit the bill. https://www.google.com/url?sa=t&sou...oQFnoECBAQBg&usg=AOvVaw23h0P4kOqSV4laiDhOhgJm


Many thanks again.

 

[Lucid]

The Distribution Amplifier has two inputs
1. Freeview
2. Sky RF Out.

The distribution amp has only one input for TV signals. It's the UHF input. The other one if for radio aerials - FM or/and DAB. If you're trying to connect the Sky RF2 Out into the FM-DAB connection then that will cause you problems straight away.

The signal path is exactly like the diagram I made for you in my previous post. But lets go through this in small steps so you can see where everything fits.

If we'd have been doing this before the 800MHz and 700MHz clearances then it would have been quite simple: Aerial signal into the aerial in of the Sky box, and then RF OUT-2 goes to whatever distribution amp. It would then have been a case of juggling the RF2 frequency to find the cleanest. Higher frequencies tend to work better, but you have to stay away from nearby mux channels by a 2channel margin both below and above.

When they completed the 800MHz clearance there were no digital TV transmissions in the RF ch 59~68 range, but there'd be something interfering. This was mobile phone mast transmissions. In order to block those, we started to use LTE 800 filters. They would clear that chunk of the frequency range and so make it free for the Sky RF2 signal.

This tech started to get built into distribution amps, but that would pose a problem for someone trying to distribute RF2 since it would also wipe out the Sky signal if set in the ch 59~68 range.

Now we have clearance in the 700MHz range too. The new range of filters block from ch50 all the way up to ch68. Filtering the aerial signal before it goes through the Sky box makes ch50 to 68 available for the Sky RF2 signal. It's important then that the aerial distribution amp doesn't have a filter too. That would wipe the same 50-68 range, and so kill the Sky RF2 signal if it was in that range.