Masthead Amplifier or Distribution Amplifiers?

hpoom · 17-11-2009, 12:29 PM

Hi all, I have done lots of searches on the forums for my answers but I'm still confused.

At the moment in my current house I have an antiference 2 way masthead amplifier and I am very pleased with it. It means I get freeview to my topfield PVR in the lounge then chain on the second tuner and onto the TV. The lounge TV does not pick up BBC channels, but I can get them on the PVR so no hastle. The second feed goes to the TV in the spare room and we get good freeview there too.

We will be moving house soon and in the new house I plan to Cat5e the whole house and while I am there I plan to send Coax to each room for Freeview, Freesat and DAB. This is where the confusion starts.

I did plan on getting a 5 way antiference masthead amp and then also getting a quad LNB for the dish that is already on the house we are going to move into. Then getting all these Coax cables (9 in total coming into the node zero I will setup an inbuilt cupboard in one of the bedrooms. From here I planned to have lots of Coax running to each room and then I could use F Connector joints to change the use of f connector face plates in each room from Sat to Freeview.

After some more reading I found out about distribution amplifiers and thought that might enable me to only do 1 run to each room carry sat, freeview and DAB on the single cable.

So my questions are:
1/ Should I stick to my old plan of lots of Coax or look into distribution amp?
2/ If I go distribution I assume I still need a masthead amp for freeview as the reception is rubbish here.
3/ Do I need PSU for this masthead amp or can I power it from the distribution amp?
4/ What if I want 2 sat or 2 freeview sockets in a single room do I then still run 2 coax? (I want to have 2 freeviews feed to the lounge 1 for topfield and 1 for TV so I can get BBC on TV)
5/ Do I need a DAB mast or can I just use the TV one for DAB reception?

Sorry for all the questions, I'm sure there will be more. Although it might not sound it I am very technical minded. Just sounds like what I have read on distribution amps I can cut down on running a lot of coax!

Thanks in advance.

grahamlthompson · 17-11-2009, 12:40 PM

Quote:

Originally Posted by hpoom

Hi all, I have done lots of searches on the forums for my answers but I'm still confused.

At the moment in my current house I have an antiference 2 way masthead amplifier and I am very pleased with it. It means I get freeview to my topfield PVR in the lounge then chain on the second tuner and onto the TV. The lounge TV does not pick up BBC channels, but I can get them on the PVR so no hastle. The second feed goes to the TV in the spare room and we get good freeview there too.

We will be moving house soon and in the new house I plan to Cat5e the whole house and while I am there I plan to send Coax to each room for Freeview, Freesat and DAB. This is where the confusion starts.

I did plan on getting a 5 way antiference masthead amp and then also getting a quad LNB for the dish that is already on the house we are going to move into. Then getting all these Coax cables (9 in total coming into the node zero I will setup an inbuilt cupboard in one of the bedrooms. From here I planned to have lots of Coax running to each room and then I could use F Connector joints to change the use of f connector face plates in each room from Sat to Freeview.

After some more reading I found out about distribution amplifiers and thought that might enable me to only do 1 run to each room carry sat, freeview and DAB on the single cable.

So my questions are:
1/ Should I stick to my old plan of lots of Coax or look into distribution amp?
2/ If I go distribution I assume I still need a masthead amp for freeview as the reception is rubbish here.
3/ Do I need PSU for this masthead amp or can I power it from the distribution amp?
4/ What if I want 2 sat or 2 freeview sockets in a single room do I then still run 2 coax? (I want to have 2 freeviews feed to the lounge 1 for topfield and 1 for TV so I can get BBC on TV)
5/ Do I need a DAB mast or can I just use the TV one for DAB reception?

Sorry for all the questions, I'm sure there will be more. Although it might not sound it I am very technical minded. Just sounds like what I have read on distribution amps I can cut down on running a lot of coax!

Thanks in advance.

A masthead amplifier and a distribution amplifier serve two purposes, a masthead amplifier is a very low noise potentially high gain device designed to be mounted as close to your aerial as possible to deliver the best signal possible to your entire system (think of it as a launch amplifier). A distribution amplifier is simply designed to recover the losses associated with splitting a signal to more than one device. Whether you need a masthead or not depends on how good a signal you get from your transmitter. The need for a distribution amp depends largely on how much signal you have to start with and how many times you want to split it. Briefly you might need both, either one or neither. Masthead amps require a seperate power supply which send the power up the cable from anywhere a coax goes from the amp

hpoom · 17-11-2009, 2:28 PM

Thanks for the fast reply. I will need a masted amp as in Kent a the downs blocks the dover transmitter.

My questions, if somebody could help answer some or all of my numbered questions, are more about should I just have a 5 way masterhead and quad LNB and then send those 9 cables round the house, or should I put this all into a distribution amp to combine Freeview, Freesat and DAB on a single coax.

I am thinking the non-distribution amp, original idea, might be best...

grahamlthompson · 17-11-2009, 4:05 PM

Quote:

Originally Posted by hpoom

Thanks for the fast reply. I will need a masted amp as in Kent a the downs blocks the dover transmitter.

My questions, if somebody could help answer some or all of my numbered questions, are more about should I just have a 5 way masterhead and quad LNB and then send those 9 cables round the house, or should I put this all into a distribution amp to combine Freeview, Freesat and DAB on a single coax.

I am thinking the non-distribution amp, original idea, might be best...

First of all you can't distribute a satellite feed like you describe. Each satellite tuner needs it's own dedicated feed to a lnb, twin tuner pvrs need two, this is because unlike an aerial a lnb is not a passive device the tuner has to pass control signals to it's lnb. The normal limit for a conventional universal lnb is 8 (octal). If you need more than this you need a bigger dish a quattro lnb and a multiswitch (not a cheap option) and you still need a seperate cable from the multiswitch to each tuner. You can multiplex terrestrial signals with one lnb feed to cut down on cabling but that's it. Which is best depends on what you want to do, if say you want to use say a twin tuner freesat pvr output in other rooms using rf it makes sense to route a single cable from a masthead amp together with two lnb feeds to the pvr loaction and then transmit the outputs of anything you want to distribute to a dis amp in the loft.

See this picture

4shared.com - photo sharing - download image FinalRFDigaram.jpg

hpoom · 17-11-2009, 4:56 PM

Thanks again graham from the explanation on satellite. That makes things a lot clearer.

Also I have not plans to distribute the output of a Freeview or Freesat PVR over coax. If I do distribute the output of a PVR will do it over HDMI and Cat5e.

So for my needs I think I will not multiplex. I will just run 4 coax to the lounge from node zero, and 4 coax to the second TV room from node zero and 1 coax to each bedroom.

Then I can use these for freeview or freesat. So to start with no sat will go to the lounge but 2 will go to the second TV room, but later I could change freeviews to sat by switching the f connetions at node zero.

Does this sounds about right? Will this work?

Also what about DAB and FM. Do I need to multiplex DAB into a TV coax and do I need a DAB/FM arial, or can I use the TV arial for DAB?

The 4 feed the the lounge I plan to be one DAB, two freeview a one spare initially, but in time I might switch the satellite (all comes down to Freesat HD or Freeview HD).

I am thinking lots of Coax is best, but am I wrong. Maybe I will draw a diagram as struggling to explain at the mo...

hpoom · 17-11-2009, 5:13 PM

So I have done an image here:

http://hpoom.100webspace.net/files/CoaxSetup.png

This diagram does not show DAB/FM as I am still unclear on how that will work?

I would have 5 coax form masthead and 4 from quad LNB all coming into the cupboard all ending in an f connector.

I would then also have 12 cables coming from the rooms in the house ending in an f connector.

I can then use coupler to send what I want to each room. So to start lounge will get 2 Freeview and a DAB and one spare, but in a year or 2 I can then change that at node zero by changin couplers to send it 2 sat, 1 freeview and 1 DAB.

Would this description work? How will DAB feature in this? Am I doing this right or should I use multiplex to reduce down to 1 or 2 cable runs to the lounge and home cinema room?

Thanks again

grahamlthompson · 17-11-2009, 5:30 PM

Quote:

Originally Posted by hpoom

So I have done an image here:

http://hpoom.100webspace.net/files/CoaxSetup.png

This diagram does not show DAB/FM as I am still unclear on how that will work?

I would have 5 coax form masthead and 4 from quad LNB all coming into the cupboard all ending in an f connector.

I would then also have 12 cables coming from the rooms in the house ending in an f connector.

I can then use coupler to send what I want to each room. So to start lounge will get 2 Freeview and a DAB and one spare, but in a year or 2 I can then change that at node zero by changin couplers to send it 2 sat, 1 freeview and 1 DAB.

Would this description work? How will DAB feature in this? Am I doing this right or should I use multiplex to reduce down to 1 or 2 cable runs to the lounge and home cinema room?

Thanks again

You can triplex, 1 lnb feed, 1 UHF aerial terrestrial feed and and a DAB Aerial onto 1 coax with some signal loss in the combining and splitting out process. You wont get mich of a signal from a UHF TV aerial for VHF radio (Band 1 for VHF and Band 3 for DAB from memory) so you will really need one antenna for each service. So yes three cables will give you 2 sat feeds plus UHF TV Plus FM. Running seperate cables will be more flexible of course. Bringing them all together so you patch them in different ways sounds a good idea.

Just one suggestion consider using an octal lnb and running 4 shotgun cables from the dish to give you more future sat tuner options

hpoom · 18-11-2009, 1:25 PM

Thanks I am now sure I will go for the lots of coax option. For the DAB FM stuff can I use a passive splitter like there:
Online TV Splitters, Amps & Diplexers sales

To split an FM or DAB feed to multiple rooms?

hpoom · 03-02-2010, 1:09 PM

I'm back thinking about this again, and I plan to build my own Coax Patch Panel using f connectors and a 1U blank panel. The issue I have is after drilling the wholes for the f connectors I can't just screw them on as the outside of the f connector will be in contact with the metal panel.

I think I need to use some kind of rubber washers so that I can screw the f connectors in to make a coax patch panel but without the outer cable of the coax making contact with the panel.

Can anybody suggest some washers for this job or any other suggestions on how to avoid this issue?

hpoom · 03-02-2010, 5:18 PM

Another idea I had was instead of constructing my own f connector patch panel. I could just buy a BNC patch panel like this:
Keene Electronics

And then use BNC ends on my cables instead of f connectors.
Would this work for Satellite and FreeView? Can I use BNC connectors, I can't see why not as stil just coax whether you use f connector, bnc connector, or push on connector.

Help needed please

Rodders53 · 03-02-2010, 5:26 PM

All the coax outers should be bonded to the main electrical earth (as should the aerial and dish metalwork). This is seldom done in domestic installations though.

So fixing them to a 1U mtal panel will actually be OK. Ideally get a good 6sq.mm earth bond up to your rack and fly-lead off that to each panel.

BNCs are most often 50ohm (although you can get 75ohm versions which you'll need for the application you propose). So do check! (Also check for losses at up to 1GHz). F-sockets are a fraction of the price.

hpoom · 03-02-2010, 9:06 PM

OK so BNC is a bad idea. I'm back to f connectors though a 1U blank panel to make a homemade patch panel.

Rodders53 Thanks for your reply. I had not realised the outer is not used for set for freeview on coax cables. I assumed both the outer and inner where used.

What you saying is that if I do short the outer to the metal 1U panel then I should earth the panel. That sounds quite extreme. Is there any risk if I don't earth the 1U panel? I already have the drop lead from the aerial and sat dish via a surge protector. Would that deal with the earthing for me???

grahamlthompson · 04-02-2010, 12:29 PM

You only need to earth bond when using a communal sat/terrestrial distribution system. This is purely to avoid possible transfer of voltages from locations supplied by a different phase (potential difference of 415V),

Screwfix sell a modular range that clip into a back plate that will fit on a standard accessory box, this includes a f connector male to male accessory (just what you need to knock up a patch board). It's best to use f connectors even for terrestrial and fit f to belling lee (male or female) adaptors when needed.

There is no difference in the connection requirements for terrestrial to satellite a 75 ohm matched connection is required with both screen and centre core connected.

hpoom · 04-02-2010, 1:41 PM

Thanks for the reply grahamlthompson

I know screwfix and many other playes sell modular ranges but I have been trying to avoid this as it would be very expensive.

My plan is to instead make a coax patch panel for my node 0 buy attatching the ends of the cables coming up from each room to an f connector, and then fixing these f connectors (12 of them) into the a blank 1U to make the patch panel.

I can then attache the other ends in each room to f connectors which I will mount though a standard blank plate to go on a single back box as this will be a lot cheaper then modular systems.

Then I will run the quad LNB drop leads and the 5 leads form the masthead amp into the node 0 and attach to the patch panel where needed.

One I get started I will post some pictures so people can se what I am going on about. My plan is that one day I can have a freeview socket in the bedroom for example and at a later time I can change that to a sat feed just by moving cables on my patch panel at the node 0.

I think I am clear on what I am doing even if others are not

grahamlthompson · 04-02-2010, 3:15 PM

Quote:

Originally Posted by hpoom

Thanks for the reply grahamlthompson

I know screwfix and many other playes sell modular ranges but I have been trying to avoid this as it would be very expensive.

My plan is to instead make a coax patch panel for my node 0 buy attatching the ends of the cables coming up from each room to an f connector, and then fixing these f connectors (12 of them) into the a blank 1U to make the patch panel.

I can then attache the other ends in each room to f connectors which I will mount though a standard blank plate to go on a single back box as this will be a lot cheaper then modular systems.

Then I will run the quad LNB drop leads and the 5 leads form the masthead amp into the node 0 and attach to the patch panel where needed.

One I get started I will post some pictures so people can se what I am going on about. My plan is that one day I can have a freeview socket in the bedroom for example and at a later time I can change that to a sat feed just by moving cables on my patch panel at the node 0.

I think I am clear on what I am doing even if others are not

If by standard blank you mean a plastic front plate they are a bit thick to enable the connectors to be secured by a nut. A thin piece of aluminium is ideal.

See here

How to fit F Connectors to coaxial cable

hpoom · 04-02-2010, 3:29 PM

Thanks that is exactly what I plan to make, using my 1U blank plate. That has always answered my queries about the metal touching the plate, as they don't seem to have an issue with that on that page.

Thanks again

grahamlthompson · 04-02-2010, 3:43 PM

Quote:

Originally Posted by hpoom

Thanks that is exactly what I plan to make, using my 1U blank plate. That has always answered my queries about the metal touching the plate, as they don't seem to have an issue with that on that page.

Thanks again

Sorry I did not realise that was the problem. There's no problem at all in commoning the screens. In a communal installation all the screens are commoned and then earth bonded for the reasons posted above. The screens are also connected together in a multilnb.