Recommend an aerial amplifier please? For FM / DAB

[TonyRPH]

I'm looking for an aerial amplifier for FM and DAB (primarily FM)

An Ebay search shows hundreds of the things, Chinese brands, well known UK brands such as Labgear etc.

I don't want to spend to much unless I can help it.

I only require a single outlet, however a dual outlet would be useful for future use.

My FM tuner currently reports around 49dB of signal, and I need about 60dB or better.

The aerial is a simple loft dipole (not easy to upgrade this to a multi element Yagi).

35 years ago, I used to install aerials and would have known right away the best amp to buy, but not anymore.

Any recommendations appreciated.

TIA.

[Alucidnation]

Those brands are still around.

[bristolracer]

The problem you have is the gain you require.

A mains powered "set back" amp will only give about 12db gain

A masthead while much higher powered 12 to 25 db are less likely to pass FM/DAB these days as they have been trimmed to stop LTE (4G) signals getting in. If you can find one rated from 47mhz to 860 then go for that, but many are now 470 to 860.
This may be ok, i suspect it is new old stock and you will need to buy a suitable power supply too.
http://www.ebay.co.uk/itm/New-Televes-8118-Outdoor...

This may also be suitable
http://www.ebay.co.uk/itm/Wolsey-Topaz-Launch-Ampl...
(no association with the seller example for illustration)

Be aware that you may need to turn the gain down on the TV input, as too much signal can be as bad as too little.

[TonyRPH]

@bristolracer

Thanks - I did wonder if the 4G filter would be an issue, even though some were stated as 47MHz to 860MHz (with 4G filter).

Is it the filter characteristic that causes reduced amplification around FM & DAB frequencies?

[megaphone]

OP. What aerial do you have in the loft? You are aware FM and DAB aerials are different, usually (but not always) on a different H & V polarity? You can get a good combined aerial, I have used these with good results when I've only had one down lead.

example. http://www.ebay.co.uk/itm/DAB-FM-AERIAL-COMBINED-A...

This is a good source of information http://www.aerialsandtv.com/fmanddabradio.html#TVa...

[megaphone]

TonyRPH said:

@bristolracer

Thanks - I did wonder if the 4G filter would be an issue, even though some were stated as 47MHz to 860MHz (with 4G filter).

Is it the filter characteristic that causes reduced amplification around FM & DAB frequencies?

4G filtering affects frequencies above 800Mhz, channel 61 and above. FM and DAB are down the bottom, up to around 215Mhz, so should not be affected.

Where are you going to position the amp? In the loft or at the equipment? AS suggested a masthead amp is better just make sure it can go down to the low frequencies.

Something like this will work, you'll need a power supply for it which can plug in downstairs.

http://www.labgear.co.uk/product-categories/amplif...

Edited by megaphone on Monday 4th September 09:44

Edited by megaphone on Monday 4th September 09:52

[TonyRPH]

megaphone said:

OP. What aerial do you have in the loft? You are aware FM and DAB aerials are different, usually (but not always) on a different H & V polarity? You can get a good combined aerial, I have used these with good results when I've only had one down lead.

example. http://www.ebay.co.uk/itm/DAB-FM-AERIAL-COMBINED-A...

This is a good source of information http://www.aerialsandtv.com/fmanddabradio.html#TVa...

I have a standard (single element) FM dipole (not even a folded dipole!) at the moment, as that's all there is space for (we have a loft conversion, so the aerial is just mounted in a void).

That aerial in your link looks quite interesting - although I'm not too bothered about DAB at this stage, it's just a nice to have (my DAB tuner is in storage).

megaphone said:

Where are you going to position the amp? In the loft or at the equipment? AS suggested a masthead amp is better just make sure it can go down to the low frequencies.

The amp will be about 1.5M downstream of the aerial. I'm using some very good quality low loss coax cable (some ex Virgin stuff I had, from a long extension), so the loss over 1.5M should be negligible. As it happens, I also have a coupler (f-type) at this distance, so it would be convenient to insert an amp at this point. All the connectors are crimped, barring the f-type which plugs into the tuner, so my connections should be pretty low loss too.

My issue at the moment is choice of amplifier - an all in one unit would be most suited to my requirements.

I've seen a Labgear (SDA243) and a Mercury (brand unknown to me) on Ebay - the Mercury is only £5 but seems to offer a respectable gain (10dB) and noise figure (<4dB) - I can't seem to find noise figures for the Labgear stuff, although the gain is slightly higher at 12dB.

Edited by TonyRPH on Monday 4th September 10:08

[Hayek]

How did you get on in the end? I'm considering similar options.

[TonyRPH]

The project was eventually abandoned, and I took a completely different path (went back to internet radio).

The 'romance' of FM was short lived!!

So I can't help unfortunately.

What I can recommend though, is that if you have a long cable run, get the lowest loss cable you can buy, as that in itself made a huge difference on my relatively short cable run.

[Hayek]

TonyRPH said:

The project was eventually abandoned, and I took a completely different path (went back to internet radio).

The 'romance' of FM was short lived!!

So I can't help unfortunately.

What I can recommend though, is that if you have a long cable run, get the lowest loss cable you can buy, as that in itself made a huge difference on my relatively short cable run.

Ok thanks. My immediate issue is the TV, although the FM antenna is in the works. Labgear have an amplifier that seems to take an input from the TV aerial and the FM aerial, not sure I want to pollute the FM before it goes to the hifi though!

I'm just trying to change to a different TV Tuner setup, the new one is complaining about a weak signal on the HD channels. My old tuner reports 66% strength, 100% quality and has no issues. My new tuner has dual tuners so I'm wondering if this is the source of the worse performance (i.e. effectively a splitter inside the unit).

My cabling is a nice new single ~6m piece of copper shielded WF100 cable from the aerial in the loft to the F-type connector on the faceplate in the living room.

[VEX]

Double, Triple check your connections on the cable to make sure you don’t have any shorts, even a single earth strand can diminish the signal cable.

Check behind the faceplate too.