Loft aerial help / boosters etc

opencube

Active Member
Trying to help a relative with their loft aerial and booster setup to solve a TV signal issue.

All had been fine with their setup until earlier this year then they could only receive scrambled Freeview channels.

Their setup was like this

Loft Aerial > loft Booster Distributer with mains plug > three outputs

The three outputs goto:

  • Small old LG portable LCD
  • 40 inch Hisense LCD
  • FM Booster > 40 inch Panasonic Plasma

I suspected it was either a fault of the loft powered distributer or 4G signal interference.

To test I unplugged and removed the powered distributer box in the loft, and bought a Labgear 4G/5G/LTE 700 Interference Filter (F5GA) , and connected one end to the aerial coaxial and the other to the coaxial that went to the FM Booster > Panasonic Plasma.

This solved the issue and channels looked v good with strong signal rating displayed on TV.

However, I still needed to have a solution that would work with all three TVs.

So I bought a mains powered Labgear LDA204LR 4 Way Distribution Amplifier to replace the old powered distribution box and it also had 4G filtering too, so could remove the single F5GA filter.

However, this didn't work. The signal is now back to being non existent/rubbish.

I thought perhaps having a powered distributer box and FM Booster to the Panasonic plasma was causing too strong a signal, but removing the FM Booster from the setup made no difference.

Am I missing something really obvious here? If so please let me know!
 

Rodders53

Distinguished Member
FM booster? Make/model/ pictures of it (any markings).
UK TV is UHF so FM (VHF radio) is wrong frequency.

What was the original loft booster amplifier make and model?

In some locations it's possible to have too much signal = overloading the TV input(s) ad the symptoms are very similar to too little signal.
BUT that is pretty unusual AND doesn't suddenly happen! TV transmitter powers and frequencies rarely change.

Having two amplifiers in circuit is a recipe for problems - but if one is a remote power supply for the remote electronics that's a different kettle of fish.

Use the TV signal strength and quality meters with aerial direct and the different amplifiers in turn (on every frequency received, ideally).
Check on all three connected TVs.

It might be worth going back to the original loft amp, but adding the 5G filter in before it. That will filter out more than the 4G filters in the new amplifier (in the exceedingly unlikely event that something in the 700-800 MHz range is the issue).
It will, of course filter out the temporary HD COM 7 ch 55 multiplex if it's available in this location.

Location (nearby shop, pub, church, school postcode) will allow use of prediction tools to confirm if overload might be an issue.
 

opencube

Active Member
FM booster? Make/model/ pictures of it (any markings).
UK TV is UHF so FM (VHF radio) is wrong frequency.
Labgear Booster Model MSE122. Can't find any reference online but there are MSE112 which looks like a single output model opposed to two of the MSE122.

Here's a pic of the MSE112
s-l640~2.jpg



What was the original loft booster amplifier make and model?

Can't remember at the moment and will need to go back to check. Been working fine for years though up until earlier this year.

In some locations it's possible to have too much signal = overloading the TV input(s) ad the symptoms are very similar to too little signal.
BUT that is pretty unusual AND doesn't suddenly happen! TV transmitter powers and frequencies rarely change.

Having two amplifiers in circuit is a recipe for problems - but if one is a remote power supply for the remote electronics that's a different kettle of fish.

Use the TV signal strength and quality meters with aerial direct and the different amplifiers in turn (on every frequency received, ideally).
Check on all three connected TVs.
The plasma downstairs has always required a second booster on it to get a good signal

Whereas the other two TVs in the house upstairs, (an old small portable LG LCD, and a hisense LCD), both worked fine without a second booster on the coaxial going into those TVs.

It might be worth going back to the original loft amp, but adding the 5G filter in before it. That will filter out more than the 4G filters in the new amplifier (in the exceedingly unlikely event that something in the 700-800 MHz range is the issue).
It will, of course filter out the temporary HD COM 7 ch 55 multiplex if it's available in this location.
Tried the single 4/5G filter before the original loft amp, didn't work.


Location (nearby shop, pub, church, school postcode) will allow use of prediction tools to confirm if overload might be an issue.

Nearby council building: Lewsey Community Centre Landrace Rd, Luton LU4 0SW


Hope this info helps others to help me!
 

opencube

Active Member
So, I have a temporary solution for it for now and have two tvs in the house with a decent signal...but im still a bit stumped on whats going on.

I now have it Loft Aerial > 4/5G single filter (in loft) > Labgear Booster (moved from downstairs by plasma to the loft) > Plasma.

This works well, signal and quality strength very good.

As the Labgear Booster has two outputs it allowed me to get a signal to one of the upstair TVs, which is all thats needed at the moment.

I am presuming that the new mains powered Labgear LDA204LR 4 Way Distribution Amplifier is a dud, or the 4g filter in it is inferior to the single filter that is labelled 4/5G.

If it is a dud, that would make three similar labgear bits of kit ive had over the last couple of years either faulty or not upto the task. So strange as always thought they were a decent brand.

In my own home we havent been able to get Freeview for a few years, and tried a powered distributor unit to no avail. Its got me thiniing that maybe its down to a single 4/5G filter might sort things.
 

Rodders53

Distinguished Member
Lewsey Farm area is Sandy Heath most likely with a possible strong signal from Luton relay (Farley Hill) of same (although poor interference predictions for Luton).
Luton MF has closed so no possibility of AM interference.
Check auto tuning hasn't stored the wrong ones? If so manual will do it properly!
Some in Luton area choose to go for Crystal Palace for London news... ?

MSA 262 has 8dB gain on the main 6 and a 22dB 'full' which - if needed - could feed the long cable run to the Plasma TV and avoid the cascaded amplifier bit? But will be very high level (+14dB on the other outlets).
There should (MUST) be a 'terminator' (75 ohm resistor in a can/TV plug) on the full output if unused. {Which I think I see on the photo as a knurled alloy part?}.

MSA 122 probably has 10dB gain or thereabouts (MSA 111/121 booklet online), so the 'full' output may not be much higher that what used to work? But won't have unwanted second amplifier noise added.

Go over all the cables, plugs and sockets and re-make any suspect or loose ones. Many problems are down to connections (poor screening or resistive joints).

Wolfbane predicts a not-line-of-sight 55dB signal level (outside at 10 metres, ref 1 microVolt). An aerial will have about 8-10 dB gain. In a loft there will be attenuation by the roof of 10 dB or so. Cables really don't lose much signal, -3 dB is a fair rule of thumb in most houses. Very long cables will lose more --- but how long is that one to this problem TV?

TVs should be presented with between 45 and 65 dB (ref 1 microVolt). So amplification shouldn't be required for one set and only low gain for multiple sets at that postcode if all is well (and no local obstructions: trees, buildings).
 

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