Boosting Signal Strength Of Analogue Aerial

[securespark]

Hi guys


My father has just e-mailed me.

He has an elderly Analogue aerial with standard 75 Ohm co-ax running to a TV with freeview digibox.

He would like to add another set with freeview.

From my own personal experience, I know in my area (SK7), the signal strength from such an aerial (I have the same) is sufficient to power three TV's with F/V boxes via a 4way SLx amp. He lives in M21.

I know the best scenario is to replace the ageing aerial with a digi aerial using cable with a foam di-electric & a mast-head amp.

However, given he has limitations with his existing aerial, what is the best way to boost the signal strength, or rather, limiting the losses, if required?

Which amps have the highest gain? I'm having trouble finding more than 6db per output.

Thanks for your input (forgive the pun..)

 

[ban-all-sheds]

Which amps have the highest gain? I'm having trouble finding more than 6db per output.

http://www.tvaerials.com/shop.aspx?categoryid=106

Mind you - are you sure that a signal 4x stronger won't be enough?

 

[gman76]

If the existing aerial is grouped to receive all multiplexes, I can't see the point in replacing it. The downlead however, would be worth upgrading, if interference spikes are a problem.

I have a four way Vision masthead from Satcure.co.uk with adjustable gain from 10 - 20dB from memory - this works lovely on min gain where I am (mind you, I can see the repeater transmitter). Probably lucky my also ageing aerial is in the loft (Antiference TC18W).

 

[electronicsuk]

Why the obsession with 6dB gain per output? If the signal into the booster is too weak then an amplifier is not the correct fix, as it amplifies EVERYTHING, not just the signals you're interested in.

If he can get a good signal on a single freeview box on the end of the downlead then even a low gain amplifier will be suitable for distributing to multiple TVs around the house.

 

[radioredcat]

I take it your recieving winter hill like myself as the aerial group is C/D for analogue and freeview,I think you would be better off getting a variable amplifier so you can adjust it to suit the incoming signal.
The noise figure is also important the lower the better,Have a look at the site below they test everything they sell and what they don't know is not worth knowing.

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

andy

 

[ericmark]

Some times you read these web sites and wonder where they learnt their trade. To send and receive weak signals it is common to stack aerials although it does take some skill to ensure they are tuned to each other and one is unlikely to be able to do that with wide band.
I have seen 9 x 17 element yagi beams on a rotator with azimuth used for bouncing signals off the moon to send Morse to and from USA on 2 meters or 144.100Mhz.
But rubbish in get rubbish out with any amplifier so the closer to aerial the better. Because of the problems in matching any passive splitters will have resistors in and to run two sets of one aerial would reduce the signal well below half for each set so where splitting active splitters are required.
If you are Winter Hill then then you can use a narrow band aerial but Moel-y-parc needs a wide band and you will need to check your area to find out.
If you are close to other transmitters, Police, Ambulance, Fire or Taxi then you may need to use something a little special but in the main there is no need to vary signal strength.
My Ariel feeder has band pass filters but that's because I also transmit from the house but not required in most cases.
Eric