Aerials Setup

[Greenie9657]

Morning All

Im in the process of going through my house fitting wired internet access, DAB and TV points in all the rooms. (theres nothing at the minute except a coax direct from my aerial, straight down the front of my house, into the living room, minging!) I was just wondering if anyone could help about the following points:

1. Im fitting these Diplex plates and am I right in thinking, I run the coax from both TV and DAB/FM aerials into my attic, connect it to an amp (pictured), then just 1 single coax is required from the OUT on the amp to run the diplex plate for TV and DAB. (as there is only one input into the diplex plate) Im using the PF/WF100 Coax as it seems to be the best at the minute. Im happy working with coax.


2. Is this AMP pictured a decent one? (im happy its got enough outputs, I was just wandering about the brand/quality). The attic is powered as im also wanting a network switch up there too.

3. Is this aerial ok (pictured) for DAB and FM signals?

Any suggestions/thoughts would be great.

Kind Regards.

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• Greenie9657
• 7 Feb 2014
• 1

(DIPLEX PLATE)

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• Greenie9657
• 7 Feb 2014
• 1

Untitled

• Greenie9657
• 7 Feb 2014
• 1

(AERIAL)

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• Greenie9657
• 7 Feb 2014
• 1

(AMP)

 

[Lucid]

1) Yes, single coax will carry TV (UHF) and FM/DAB (VHF) signals mixed (multiplexed) in a single "stream". The diplex plates split it back out in to separate signals again.

2) I like Proception gear. I've used it on several jobs to good effect. Touch wood it has never let me down.

3) Aerials.... the one you pictured will work, but how well depends more about the strength of signal in your area.

If it's a strong signal area, then the losses from the smaller amount of metal in the air and having the dipole set at 45 degrees so it works to a fashion for DAB (vertical) and FM (horizontal) polarisations might not matter.

The other advantage of the aerial design in your picture is that it's not so sensitive to transmitter direction.

Personally I go for a dual aerial setup. A dedicated FM and DAB arrangement with the signals multiplex on the mast head. IMO DAB is crap for anything other than talk stations. But unfortunately that's our future as dictated by greedy and short-sighted Governments FM is still very good; particularly where there's care taken with programme material and studio transmission quality e.g. Proms on BBC radio. Then again I value quality over convenience but I can see how that might not be practical for everyone, so c'est la vie

Final thoughts.... Have a think if you want to distribute Sky around the house via the TV coax. All that takes is a down-lead from the roof aerial to the lounge, and then an up-lead back to the loft. Make sure the amp can do SkyPass.

 

[Greenie9657]

Hi lucid

Do you know any web sites that show the dual aerial setup up and a mast multiplexer just so I can try and pic what you are talking about?

As I'm at the bottom of a hill, not steep but enough, when tuned into FM a little crackling is heard and like wise when DAB is selected. (Not crackling but you get the interference) Not the greatest range of channels either. Would a different aerial suit?

Thanks

 

[Sam Gangee]

Crackling indicates a weak signal but could be exacerbated by poor cable/connections or local interference. If it really is a poor signal then separate high-gain aerials with correct polarisation, aimed in the optimum direction(s)* should improve it.

Regarding diplexers, this might help.
http://www.satcure.co.uk/tech/combiners.htm

* Not necessarily in the direction of the transmitter(s). You'd have to determine it by trial and error, since you don't have a clear line of sight. Try it near ground level first and don't bother with a diplexer until you have each aerial working separately.

 

[Lucid]

This triplexer is a 3-way combiner. Separate inputs for your TV aerial, FM aerial and DAB aerial. A single down lead carries all three signals multiplexed in to one. You can use it just to combine FM and DAB, then feed that signal in to your loft amp on the FM/DAB leg. TV aerial signals would go to the loft amp in the normal way.

There are a couple of caveats with any device that combines signals. The one that might affect you is signal loss. There's always a bit of loss because of the device itself. So if your signal is very weak even with a good aerial correctly aligned then you should think twice before using combiners and splitters.

Unlike TV signals which all tend to come from a single mast serving a region, FM and DAB may be from transmitters in different locations. A dipole aerial picks up equally from all directions so long as it isn't blocked by buildings, structures or geography. The trade-off is sensitivity. It won't do so well with the weaker or more distant transmitters.

Aerials with more elements tend to be higher gain*. This also means they are more directional. You'll get a much stronger signal from transmitters in the aerial's path, but not so much from those to the sides or behind.

You could do with working out where the main transmitters are for the stations you listen to, and then choose the most appropriate type of aerial for each. Here's a link to the UK transmitter location map: http://www.ukfree.tv/radiomaps.php



* read the gain figure rather than just assuming more elements equals higher gain.

 

[Sam Gangee]

I told you what to do and Lucid has explained in detail why I suggested buying high-gain aerials, testing them separately, and locating the optimum direction empirically.

BTW I'm not happy to use the word "multiplexing". In my personal experience, it's used more nowadays to describe the encoding of several digital programmes into a single channel centred on a specific frequency.

In the case of received aerial signals, I prefer to use "combining" and "decombining", of aerial signals, using diplexers or triplexers as appropriate because the digital programmes are already "multiplexed" into several specific "UHF channels". (I feel that I'm not explaining this very well!) Anyway, it's purely a matter of nomenclature and avoiding ambiguity.[/i]

* Look for the aerial gain figure in "dBd". If it's expressed in "dBi" subtract 2.1 to get the true figure in "dBd". Many suppliers cheat by using the wrong units of measurement (or none at all - in which case assume "dBi").

 

[Sureitsoff?]

Hi lucid

Do you know any web sites that show the dual aerial setup up and a mast multiplexer just so I can try and pic what you are talking about?

As I'm at the bottom of a hill, not steep but enough, when tuned into FM a little crackling is heard and like wise when DAB is selected. (Not crackling but you get the interference) Not the greatest range of channels either. Would a different aerial suit?

Thanks

have look on this site especially their aerial tests

http://www.aerialsandtv.com/index.html

http://www.aerialsandtv.com/aerialtestsfullresults.html#FM&DABreadings

 

[Sam Gangee]

That's Justin's site and he's brilliant. However, I find it difficult to draw a conclusion from those test result tables.

 

[Greenie9657]

Just wondering what are your thoughts on using satcures ANTIFERENCE A281LR PRO 8 way amplifier? A lot cheap than the amp I posted previous.

Also I had a look at those transmitters for FMa be AM and there's one not too fat from here, about half a mile away so the aerial I posted in the OP should be ok.

 

[Sam Gangee]

It's good that you just know the aerial will be OK without doing the tests I suggested.

I don't understand why you need an amplifier.

 

[Greenie9657]

I'm not sure I do either Sam, but I needed the signal split 8 ways so I just thought I'd use an amp to do it. What would you do?

2 rooms already run faceplates upto the attic. So I'd still want to split the signal up there.

 

[Sam Gangee]

OK, in that case the A281LR or similar should do the job. Keep the coaxial cable between it and the aerial(s) reasonably short but not less than 1 metre.

 

[Greenie9657]

Thanks Sam, I'll take a look. What is the difference between that one and the one in the OP?

 

[Sam Gangee]

I can't see a model number on the Proception amplifier so you'll have to determine what it is and look up the specification then compare the two.

 

[Lucid]

It's a Proception proAMP28R http://www.blake-uk.com/downloads/pdf/instructions/PA2011-9043-01_(proAMPs%20Mk%203).pdf

I've only ever used the Proception phantom powered stuff. I like that because it's small, neat and means I don't have to worry about leaving a mains powered device unattended in a loft for years.