Split my aerial input, can no longer get Freeview HD

blizeH

Active Member
Hi all,

I have recently split the input that goes into my aerial splitter box, meaning instead of the aerial going directly into it, I've used a joiner so it has the Sky going into it too (meaning I can get Sky in each room)

http://imgur.com/a/JRbLm

This works perfectly now, in that I can get Sky in each room, and Freeview on each TV in the house that supports it, but since doing this, the TV in the bedroom just displays a blank picture now for the HD channels

Is there anyway around this? Maybe purchasing some kind of booster, or maybe a new splitter to go into the attic that can amplify the signal better? I've already switched the 'strength' of the box all the way onto full, to no avail.

Thanks!
 

Peter Rhea

Active Member
One possibility is a conflict between the output of the Skybox modulator & the UHF channel carrying the HD multiplex.

The Skybox output should be at least 2 channels away from anything else wanted.
 

Peter Rhea

Active Member
You'll first have to find out what UHF channels the Freeview services are carried on.

Then go into the Skybox 'secret' service menu; on your remote quickly press Services-4-0-1-Select or Services-0-0-1-Select on a HD box.

The option for RF outlets should show which channel is currently in use & allow you to change it, if needed.
 

blizeH

Active Member
Oh wow, thank you! I never even knew there was a hidden services menu (unfortunately I also only have a Harmony remote, with afaik no services button, but I shall look for that later!) and shall experiment with different frequencies, hopefully I can find one that doesn't conflict with the Freeview HD channels.
 

blizeH

Active Member
Okay, just a heads up, I tried this and had no joy, I then disconnected the aerial from the Sky and I still can't pickup any Freeview HD channels, seems to be a signal strength issue? :(
 

Rodders53

Distinguished Member
It's odd in that, typically, people report the HD signals are more robust and often work with lower strength than SD.

In order to give considered, constructive advice we need to know where (approx) you live (so we know which transmitter you use).

Presumably reconnecting the aerial direct to the distribution amplifier brings the HD signals back in the bedroom?

Do you only have the one aerial cable between the amplifier and lounge (where the Sky box is)? The usual way to do what you want is to pass the aerial signal down to the Sky box and use its RF2 out to feed back to a distribution point to all the other TVs. {However, as it seems you need the signal amplified before passing it downstairs this may not be the correct course in your particular case}. One solution might be to have an extra lowish gain (6 to 8dB) aerial amplifier before you 'combine' the aerial and Sky signal?
 

Peter Rhea

Active Member
Okay, just a heads up, I tried this and had no joy, I then disconnected the aerial from the Sky and I still can't pickup any Freeview HD channels, seems to be a signal strength issue? :(

What exactly did you try though? Which UHF channel carries the HD mux in your area & what channel was the Skybox output set to?

Also, just to clarify, is this bedroom tv the only Freeview HD capable set? ie it's a problem with the HD signal, not one particular tv or room.
 
Last edited:

blizeH

Active Member
Many thanks again for your replies, I'll try and be as descriptive as I possibly can!

With regards to the UHF channel, I believe I set the frequency to 33, or something? Maybe it was 233, I can't remember, I'll check tonight, although I thought since I disconnected the RF cable from the Sky box it shouldn't matter too much. I looked on Google to see which UHF my Freeview HD uses and found nothing unfortunately.

I live in Quedgeley (Gloucestershire) and yes, it's the only TV in the house with Freeview HD unfortunately. The cable literally goes from the Sky box -> join with aerial -> amplifier -> rest of house. I haven't tried removing the join yet, but I assume it's fine without it since I've never had a problem before (also I'm scared of going back into the attic right now after finding a hornet in there, eek!)
 

Peter Rhea

Active Member
Here is the Digital UK postcode checker trade view result for a random Quedgeley postcode (you can try your own).

It shows decent reception prospects from 3 transmitters, but purely local factors such as hills, trees & other buildings can change all this.

Using UHF channel 33 for the Skybox output would be fine if you're receiving from any of these sites.
 

Gavtech

Administrator
BlizeH - You have not mentioned it, but it is important to check: Have you retuned the TV at any stage? Either when you lost the HD channels or since making other changes.

If you have not retuned at all - DO NOT do so at this stage.
 

blizeH

Active Member
Many thanks Peter, seems to be fine - and Gavtech, unfortunately I have re-tuned the TV (many times!)

Quite desperate to sort this now, since I've noticed that on certain channels the signal isn't very clear and you get occasional popping/squeaking noises in the sound too - my plans to watch Question Time in bed tonight (in SD, not even in HD!) could have been dashed, nooo!
 

Rodders53

Distinguished Member
Quite desperate to sort this now,
Assuming the gain control knob on the amplifier is already at maximum, all you can do quickly is to remove the 'combiner' and feed the aerial direct to the distribution amplifier (DA).

That will lose the Sky box feed but should restore the Freeview reception you had before you modified the wiring.

Do you need the Sky feed to go to all the other 4 rooms? If only one needs it you could combine the Sky feed and the one room's output from the 4-way DA to that room only?

If you do need it for all the others then the only other thing is to do is to amplify the aerial signal before you combine it with the Sky feed and distribution unit as I suggested in my previous post in this thread.

[I assume you don't have TV stations stored in the 800s on these receivers that are 'good quality copies' of the problem ones... that would suggest reception from multiple transmitters and need a manual tune, based on the transmitter your aerial points to (probably Ridge Hill, we think)]
 
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blizeH

Active Member
Many thanks again for the info, I shall try and amplifier I think, but check 100% later that the amplifier is currently pushed all the way up. I don't have any TV stations stored in the 800s unfortunately, although they do show up on my TV guide, just without anything in the channel description, hmm.

Is it worth me also trying a different splitter, just in case that one is faulty? Long shot I know. I guess I could also try a manual tune just to one of the HD channels, so I'll look up on how to do that now.

One final question, if none of this works and I do need a new device, which one would you recommend? I can only find ones like this on Ebay which are 1 input and 2 outputs, I guess I want it the other way around!

Thanks
 

Rodders53

Distinguished Member
Is it worth me also trying a different splitter, just in case that one is faulty?
<snip>
One final question, if none of this works and I do need a new device, which one would you recommend? I can only find ones like this on Ebay which are 1 input and 2 outputs, I guess I want it the other way around!
Yes if you have another. Don't bother spending any money though.

You need a 1-way amplifier between the aerial and the splitter in reverse (aka a 'combiner'), leaving the Sky input where it is.

This 1-way amplifier is to make up the losses in the splitter (4dB inductive, to 6dB for a resistive type). One with variable gain may be best but do not be tempted to get a 'high gain' one - in this instance bigger isn't better.

1 WAY aerial signal amplifier freeview & digital TV booster tele television SLx | eBay is an example. It claims 0dB (unity gain) at 'min' to +14dB (around 30x gain) at 'max'.

It's never ideal to cascade two amplifiers but your aerial seems (from your descriptions) to only be providing 'just enough' when going via the 4-way amp direct in, so it needs improving (larger array) or amplifying.
 

Peter Rhea

Active Member
. . . if none of this works and I do need a new device, which one would you recommend?

A diplexer is a frequency selective combiner which has lower losses & no unpredictible interactions between the inputs as they are better isolated than the standard splitter/combiner.

For the Skybox setup, you need one that passes VHF frequencies on the lower frequency leg (for the magic eyes) & your tv channels will have to be in the range of the high leg.

Unfortunately, this won't be the case if you're receiving from Ridge Hill.
 

blizeH

Active Member
Many thanks again for the replies and info guys, for what it's worth I've just tried getting the Sky Magic Eye working, and even after seeing the RF power to On, it doesn't even light up. I think I need to maybe boost the strength of both signals but I'm not sure.

Is there anything which will amplify two signals, or am I pretty much screwed? If so I'll go with that booster above and just cross my fingers :) Thanks again
 

Rodders53

Distinguished Member
Many thanks again for the replies and info guys, for what it's worth I've just tried getting the Sky Magic Eye working, and even after seeing the RF power to On, it doesn't even light up. I think I need to maybe boost the strength of both signals but I'm not sure.

Is there anything which will amplify two signals, or am I pretty much screwed? If so I'll go with that booster above and just cross my fingers :) Thanks again
The splitter you have will almost certainly not pass DC for the magic eyes - although you can get ones that do.

Similarly it is unlikely that the 4-way amplifier will pass the DC required and may not be able to pass back the VHF signal - again you can get ones that do this. {If you can find the make and model number it should be possible to check that all out).
 

Rodders53

Distinguished Member
Would something like this be a good buy?

NO. Because one input is for VHF/DAB radio and is filtered to not pass UHF signals, so you'll still need to sort out the aerial signal levels and how to combine them..

There is a chance your amplifier will be OK with the magic eyes... test by plugging the Sky feed direct into the amplifier (where the aerial was in originally). While there you'll be able to find any make and model numbers on it.

All the boxes that are available to do this 'magic eye distribution' assume the RF2 output fed to them contains the UHF aerial signals as well as the modulated Sky picture.
 

blizeH

Active Member
Ah! Thank you, that's a great spot, I didn't even realise that. I'm at a bit of a loss on what to do to be honest, I'll try as you suggested and plug the Sky directly into the input and see if the magic eye lights up, although as you said it's unlikely, and still wouldn't help too much in that I'd need the other input.

Damn.

By the way I turned the gain up on the device (I believe?) and the number of channels I can get has actually dropped, sigh: imgur: the simple image sharer
 

Rodders53

Distinguished Member
By the way I turned the gain up on the device (I believe?) and the number of channels I can get has actually dropped, sigh:
Gain is at max when the knob points to 'weak signal areas' (clockwise) and min when at 'strong signal areas' (anti-clockwise).

That suggests the amplifier is possibly 'overloading' the TVs... and not a 'weak' aerial signal at all? :confused:

More things to try, for you to help us diagnose :

1. connect the splitter to one TV at a time (the troublesome bedroom one to start with, perhaps) by using a 'coupler/joiner/barrel' on the end of the 'splitter/combiner' . Do you get all the channels then?
2. If you connect the aerial alone to the one TV via the joiner. Is that now OK?

If the answer to 1 is NO and 2 is YES then the Sky box RF channel may need retuning (perhaps set it to ch 68 or 69?) OR the addition of noise from the Sky circuit is upsetting things... Solution may well be to route aerial via Sky box RF input and back up on a new cable to the loft?

If answer to 1 is YES, and using the amplifier on minimum gain doesn't work OK then maybe you still have too much gain in the amplifier. This is where I then suggest you try another passive splitter to feed two sets...

However, before doing that: do try the aerial direct into the amplifier and see if the bedroom TV is happy. {I'm wondering if it was fed from one leg of the splitter previously in your first pic - which would have been a slightly attenuated (lower) signal to it??}

This type Labgear 2-Way Splitter with Power Pass All Ports | Screwfix.com is probably suitable for 'power pass' to magic eyes, but you'l need to adapt from F-plug to Belling Lee/IEC via (for example) Labgear F Plug To Coax Socket Pack of 10 | Screwfix.com.
 

blizeH

Active Member
Many thanks again Rodders, I'll try retuning the Sky RF channel and see if I get any light on the Magic Eye, if not, I shall try connecting the Sky output cable straight into the amplifier I have, and if it then works, I will purchase the Labgear splitter and the coax socket adapters you recommended, thank you :)

Interesting you said about potentially the amplifier is overloading the TVs? Does that mean I should try switching it onto the 'Medium' or even 'Strong' setting before potentially investing in any extra boosters? Being stupid I'm not even sure if it's set to weak signals anyway, it doesn't seem to be as clear as I'd have liked (what's the 6 turns about?)

Really sorry to continuously be so stupid about this by the way :/
 

GaryMo

Well-known Member
Many thanks again Rodders, I'll try retuning the Sky RF channel and see if I get any light on the Magic Eye, if not, I shall try connecting the Sky output cable straight into the amplifier I have,

Retuning won't enable/disable the red LED on the magic eyes, the only way to enable/disable them is to turn on the power to them in the hidden menu as posted above.
 

blizeH

Active Member
Thanks Gary, I've already got that turned on I believe, it's just not receiving the signal due to either the join I have, or the amplifier. One of them (or both of them) are blocking the signal.

Ideally I'd just buy a new thing with two inputs and 5+ outputs that supports magic eyes but I can't find anything ;_; I think the stuff that Rodders has recommended could be a great alternative though, once again thank you :)
 

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