An interesting problem with my parents TV reception occurred a while back.

My parents set-up was as follows. A high gain digital TV aerial on the roof,
pointed towards the Belmont transmitter. This fed into a 6-way TV booster in
the loft, which supplied TV signals to outlets in the 3x upstairs bedrooms,
2x outlets to the living room (front and rear) and to 1x outlet in the
back/dining room.

The TV booster had a Wickes badge on the front, but was manufactured by
Labgear. It was one of their older models which I had installed back in
1990, but the digital TV reception through it had been fine, up until a few
months ago....

Then one day, the reception went on several of the channels. BBC1 & 2 was
poor, but ITV and CH4 & 5 seemed OK. Checking the signal strength on the
sets, the strength was quite high (90%) but the signal quality was poor.
Even on the good channels, quality was only about 20%, despite the strength
being over 90%.

The one exception being the set in the back/dining room, in which the
reception was perfect and signal strength and quality were both around 90%,
which was odd.

I actually found that the reception on the other sets was fine when the
outlets where linked direct to the aerial and not through the booster.

Anyway, have replaced the old booster with a new one, think its a Tri-star
model, which I got from B&Q (think they're made by Philex?) and reception on
all sets is now excellent.

What I was curious about though was firstly, was this simply a case of the
old booster developing a fault, or or was it that they altered the digital
broadcast somehow (upped the power, changed the transmission frequencies or
something) a few months back that was causing some sort of interference with
the booster, due to its age? In either case, how come the reception was fine
on the set in the back room?

Any thoughts on this? Just trying to make sense of the anomalous results I
got.


--
Best Wishes
Simon Taylor

On Thu, 2 Jul 2015 21:59:34 +0100
"Simon T" wrote:

An interesting problem with my parents TV reception occurred a while
back.

My parents set-up was as follows. A high gain digital TV aerial on
the roof, pointed towards the Belmont transmitter. This fed into a
6-way TV booster in the loft, which supplied TV signals to outlets in
the 3x upstairs bedrooms, 2x outlets to the living room (front and
rear) and to 1x outlet in the back/dining room.

The TV booster had a Wickes badge on the front, but was manufactured
by Labgear. It was one of their older models which I had installed
back in 1990, but the digital TV reception through it had been fine,
up until a few months ago....

Then one day, the reception went on several of the channels. BBC1 & 2
was poor, but ITV and CH4 & 5 seemed OK. Checking the signal strength
on the sets, the strength was quite high (90%) but the signal quality
was poor. Even on the good channels, quality was only about 20%,
despite the strength being over 90%.

The one exception being the set in the back/dining room, in which the
reception was perfect and signal strength and quality were both
around 90%, which was odd.

I actually found that the reception on the other sets was fine when
the outlets where linked direct to the aerial and not through the
booster.

Anyway, have replaced the old booster with a new one, think its a
Tri-star model, which I got from B&Q (think they're made by Philex?)
and reception on all sets is now excellent.

What I was curious about though was firstly, was this simply a case
of the old booster developing a fault, or or was it that they altered
the digital broadcast somehow (upped the power, changed the
transmission frequencies or something) a few months back that was
causing some sort of interference with the booster, due to its age?
In either case, how come the reception was fine on the set in the
back room?

Any thoughts on this? Just trying to make sense of the anomalous
results I got.



It could have been a solder joint on the booster's PCB gone bad.

--
Davey.

On 02/07/2015 21:59, Simon T wrote:
An interesting problem with my parents TV reception occurred a while back.

My parents set-up was as follows. A high gain digital TV aerial on the
roof, pointed towards the Belmont transmitter. This fed into a 6-way TV
booster in the loft, which supplied TV signals to outlets in the 3x
upstairs bedrooms, 2x outlets to the living room (front and rear) and to
1x outlet in the back/dining room.

The TV booster had a Wickes badge on the front, but was manufactured by
Labgear. It was one of their older models which I had installed back in
1990, but the digital TV reception through it had been fine, up until a
few months ago....

Then one day, the reception went on several of the channels. BBC1 & 2
was poor, but ITV and CH4 & 5 seemed OK. Checking the signal strength on
the sets, the strength was quite high (90%) but the signal quality was
poor. Even on the good channels, quality was only about 20%, despite the
strength being over 90%.

The one exception being the set in the back/dining room, in which the
reception was perfect and signal strength and quality were both around
90%, which was odd.

Depends a bit where you are. My parents high gain antenna catches the
Welsh transmitter in a sidelobe and their daft old Panasonic TV puts
first found into the standard channel positions. Which means all
channels turn into Welsh if an autoretune occurs (now disabled).

It was fine until D-day when the Xmit power levels were increased.

It is possible that when digital switchover occurred and they boosted
the Welsh transmitter power significantly that this could lead to
intermodulation distortion in your ageing booster amplifier.

I actually found that the reception on the other sets was fine when the
outlets where linked direct to the aerial and not through the booster.

Anyway, have replaced the old booster with a new one, think its a
Tri-star model, which I got from B&Q (think they're made by Philex?) and
reception on all sets is now excellent.

What I was curious about though was firstly, was this simply a case of
the old booster developing a fault, or or was it that they altered the
digital broadcast somehow (upped the power, changed the transmission
frequencies or something) a few months back that was causing some sort
of interference with the booster, due to its age? In either case, how
come the reception was fine on the set in the back room?

Any thoughts on this? Just trying to make sense of the anomalous results
I got.

It could be that the booster has gone bad. Does it still ruin the signal
if you interpose it in the new signal path at the TV end?

Or do the TVs that coped still cope and those that didn't still fail?

Some TVs are tetchy about signal levels and will misbehave if the aerial
input signal is too strong as well as too weak.

--
Regards,
Martin Brown

On 02/07/2015 23:11, Davey wrote:
On Thu, 2 Jul 2015 21:59:34 +0100
"Simon T" wrote:

An interesting problem with my parents TV reception occurred a while
back.

My parents set-up was as follows. A high gain digital TV aerial on
the roof, pointed towards the Belmont transmitter. This fed into a
6-way TV booster in the loft, which supplied TV signals to outlets in
the 3x upstairs bedrooms, 2x outlets to the living room (front and
rear) and to 1x outlet in the back/dining room.

The TV booster had a Wickes badge on the front, but was manufactured
by Labgear. It was one of their older models which I had installed
back in 1990, but the digital TV reception through it had been fine,
up until a few months ago....

Then one day, the reception went on several of the channels. BBC1 & 2
was poor, but ITV and CH4 & 5 seemed OK. Checking the signal strength
on the sets, the strength was quite high (90%) but the signal quality
was poor. Even on the good channels, quality was only about 20%,
despite the strength being over 90%.

The one exception being the set in the back/dining room, in which the
reception was perfect and signal strength and quality were both
around 90%, which was odd.

I actually found that the reception on the other sets was fine when
the outlets where linked direct to the aerial and not through the
booster.

Anyway, have replaced the old booster with a new one, think its a
Tri-star model, which I got from B&Q (think they're made by Philex?)
and reception on all sets is now excellent.

What I was curious about though was firstly, was this simply a case
of the old booster developing a fault, or or was it that they altered
the digital broadcast somehow (upped the power, changed the
transmission frequencies or something) a few months back that was
causing some sort of interference with the booster, due to its age?
In either case, how come the reception was fine on the set in the
back room?

Any thoughts on this? Just trying to make sense of the anomalous
results I got.



It could have been a solder joint on the booster's PCB gone bad.

If it was suddenly and fairly recently could it have been anything to do
with 4G being enabled on a local phone mast? I cant say why this
wouldn't have affected everything equally other than perhaps different
cable lengths being affected differently by the interference? Its just a
guess but your new booster may have a 4G filter built in.

--
CB

Simon T wrote:
An interesting problem with my parents TV reception occurred a while back.

My parents set-up was as follows. A high gain digital TV aerial on the
roof, pointed towards the Belmont transmitter. This fed into a 6-way TV
booster in the loft, which supplied TV signals to outlets in the 3x
upstairs bedrooms, 2x outlets to the living room (front and rear) and to
1x outlet in the back/dining room.

The TV booster had a Wickes badge on the front, but was manufactured by
Labgear. It was one of their older models which I had installed back in
1990, but the digital TV reception through it had been fine, up until a
few months ago....

Then one day, the reception went on several of the channels. BBC1 & 2
was poor, but ITV and CH4 & 5 seemed OK. Checking the signal strength on
the sets, the strength was quite high (90%) but the signal quality was
poor. Even on the good channels, quality was only about 20%, despite the
strength being over 90%.

The one exception being the set in the back/dining room, in which the
reception was perfect and signal strength and quality were both around
90%, which was odd.

I actually found that the reception on the other sets was fine when the
outlets where linked direct to the aerial and not through the booster.

Anyway, have replaced the old booster with a new one, think its a
Tri-star model, which I got from B&Q (think they're made by Philex?) and
reception on all sets is now excellent.

What I was curious about though was firstly, was this simply a case of
the old booster developing a fault, or or was it that they altered the
digital broadcast somehow (upped the power, changed the transmission
frequencies or something) a few months back that was causing some sort
of interference with the booster, due to its age? In either case, how
come the reception was fine on the set in the back room?

Any thoughts on this? Just trying to make sense of the anomalous results
I got.



I've just had a secondary Labgear booster die. Been in service for
maybe 5 years, first one I've ever had fail. Fortunately I always buy
these things for stock, so there was a spare one on the shelf. The
original Labgear loft booster is now 42yrs old and going as good as new!

On 02/07/2015 21:59, Simon T wrote:
An interesting problem with my parents TV reception occurred a while back.

My parents set-up was as follows. A high gain digital TV aerial on the
roof, pointed towards the Belmont transmitter. This fed into a 6-way TV
booster in the loft, which supplied TV signals to outlets in the 3x
upstairs bedrooms, 2x outlets to the living room (front and rear) and to
1x outlet in the back/dining room.

The TV booster had a Wickes badge on the front, but was manufactured by
Labgear. It was one of their older models which I had installed back in
1990, but the digital TV reception through it had been fine, up until a
few months ago....

Then one day, the reception went on several of the channels. BBC1 & 2
was poor, but ITV and CH4 & 5 seemed OK. Checking the signal strength on
the sets, the strength was quite high (90%) but the signal quality was
poor. Even on the good channels, quality was only about 20%, despite the
strength being over 90%.

The one exception being the set in the back/dining room, in which the
reception was perfect and signal strength and quality were both around
90%, which was odd.

I actually found that the reception on the other sets was fine when the
outlets where linked direct to the aerial and not through the booster.

Anyway, have replaced the old booster with a new one, think its a
Tri-star model, which I got from B&Q (think they're made by Philex?) and
reception on all sets is now excellent.

What I was curious about though was firstly, was this simply a case of
the old booster developing a fault, or or was it that they altered the
digital broadcast somehow (upped the power, changed the transmission
frequencies or something) a few months back that was causing some sort
of interference with the booster, due to its age? In either case, how
come the reception was fine on the set in the back room?

Any thoughts on this? Just trying to make sense of the anomalous results
I got.

I would suggest that the booster developed a parasitic oscillation that
would substantially increase the noise floor.

Why the two TVs have different symptoms is less clear, perhaps the
receivers have different performances and the lengths of cables may have
a bearing through different filtering characteristics.

Simon T wrote:
An interesting problem with my parents TV reception occurred a while back.


DIY amps often develop a fault in which the smooth DC generated
internally has ripple on it. This superimposes a waveform on the muxes
which affects different TV sets to different degrees. Some TV sets can
be unaffected. An affected set will typically show good strength but
poor or fluctuating quality.

Or it could be 4G or some other strong signal swamping the old amp. Many
of the older amps are an open door from 40MHz to light.

Bill

Thanks for the replies everybody.

I'll put it down to the old booster developing a fault then.

Again, new booster is working nicely. So hopefully there will be no more
problems for a while.

--
Best Wishes
Simon Taylor

In article , Bill Wright
writes
Simon T wrote:
An interesting problem with my parents TV reception occurred a while back.


DIY amps often develop a fault in which the smooth DC generated
internally has ripple on it. This superimposes a waveform on the muxes
which affects different TV sets to different degrees. Some TV sets can
be unaffected. An affected set will typically show good strength but
poor or fluctuating quality.

Or it could be 4G or some other strong signal swamping the old amp.
Many of the older amps are an open door from 40MHz to light.

Bill
Roughly how far from the 4G transmitter to be safe from this?
--
bert

On 03/07/2015 13:27, Bill Wright wrote:

DIY amps often develop a fault in which the smooth DC generated
internally has ripple on it. This superimposes a waveform on the muxes
which affects different TV sets to different degrees. Some TV sets can
be unaffected. An affected set will typically show good strength but
poor or fluctuating quality.

Spot-on Bill, as usual. The PSU in those amps was just a mains
transformer, bridge rect, reservoir cap and 78xx regulator. Almost
certainly the reservoir cap has failed o/c. Very simple to repair, of
course.

Or it could be 4G or some other strong signal swamping the old amp. Many
of the older amps are an open door from 40MHz to light.

True, 'light' being about 2GHz in this case. However if an 800MHz 4G
base station has come on-air nearby it's likely the OP would have had a
postcard from 'at800' offering a free filter.

--
Andy (ex-Labgear 1978-2014)

Well assuming the cables are still the same ones as before, it kind of
sounds like the outputs or at least some of them weere faulty. Normally
though, as has been noted before, its normally input overload whether it be
by 4G or other transmission that causes poor quality reception.
Brian

--
From the Sofa of Brian Gaff Reply address is active
"Simon T" wrote in message
...
An interesting problem with my parents TV reception occurred a while back.

My parents set-up was as follows. A high gain digital TV aerial on the
roof, pointed towards the Belmont transmitter. This fed into a 6-way TV
booster in the loft, which supplied TV signals to outlets in the 3x
upstairs bedrooms, 2x outlets to the living room (front and rear) and to
1x outlet in the back/dining room.

The TV booster had a Wickes badge on the front, but was manufactured by
Labgear. It was one of their older models which I had installed back in
1990, but the digital TV reception through it had been fine, up until a
few months ago....

Then one day, the reception went on several of the channels. BBC1 & 2 was
poor, but ITV and CH4 & 5 seemed OK. Checking the signal strength on the
sets, the strength was quite high (90%) but the signal quality was poor.
Even on the good channels, quality was only about 20%, despite the
strength being over 90%.

The one exception being the set in the back/dining room, in which the
reception was perfect and signal strength and quality were both around
90%, which was odd.

I actually found that the reception on the other sets was fine when the
outlets where linked direct to the aerial and not through the booster.

Anyway, have replaced the old booster with a new one, think its a Tri-star
model, which I got from B&Q (think they're made by Philex?) and reception
on all sets is now excellent.

What I was curious about though was firstly, was this simply a case of the
old booster developing a fault, or or was it that they altered the digital
broadcast somehow (upped the power, changed the transmission frequencies
or something) a few months back that was causing some sort of interference
with the booster, due to its age? In either case, how come the reception
was fine on the set in the back room?

Any thoughts on this? Just trying to make sense of the anomalous results I
got.


--
Best Wishes
Simon Taylor

En el artículo , Simon T darkangel5@REMOVET
HISBITlineone.net escribió:

What I was curious about though was firstly, was this simply a case of the
old booster developing a fault

My money would be on bad caps in the booster power supply. The age is
about right, and it's been hot recently, which will have hastened the
demise of the booster with it being in the loft.

The one problem-free output is harder to explain away - perhaps it's a
direct feed from the aerial and is not actually amplified.

--
(\_/)
(='.'=)
(")_(")

On 03/07/2015 22:31, Andy Wade wrote:
On 03/07/2015 13:27, Bill Wright wrote:

DIY amps often develop a fault in which the smooth DC generated
internally has ripple on it. This superimposes a waveform on the muxes
which affects different TV sets to different degrees. Some TV sets can
be unaffected. An affected set will typically show good strength but
poor or fluctuating quality.

Spot-on Bill, as usual. The PSU in those amps was just a mains
transformer, bridge rect, reservoir cap and 78xx regulator. Almost
certainly the reservoir cap has failed o/c. Very simple to repair, of
course.

You may recall I had a similar problem with a (decent) Labgear amp when
I moved in here. Good enough levels coming out of it, but poor quality.
Looking at an analogue channel at the time, you could see a noise
pattern in the output that was similar to "run through" from an adjacent
out of sync channel[1], however in this case it was fixed in position
and not moving at all.

[1] Horizontal bar about 1/10th screen height, and a narrower vertical
one offset from the left of frame.

Replaced it with a passive splitter and a variable gain proception
masthead amp. Been fine ever since.


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On 04/07/2015 19:13, John Rumm wrote:
On 03/07/2015 22:31, Andy Wade wrote:

You may recall I had a similar problem with a (decent) Labgear amp when
I moved in here. Good enough levels coming out of it, but poor quality.
Looking at an analogue channel at the time, you could see a noise
pattern in the output that was similar to "run through" from an adjacent
out of sync channel[1], however in this case it was fixed in position
and not moving at all.

The beauty of analogue was that the trained eye could see what was
wrong, well-nigh immediately. Digital just falls off its cliff.

[1] Horizontal bar about 1/10th screen height, and a narrower vertical
one offset from the left of frame.

Cross-mod, by the sound of it.

Replaced it with a passive splitter and a variable gain proception
masthead amp. Been fine ever since.

I think the Proception amps are proving pretty reliable. The
mains-powered units all have decent quality 105 deg caps in the PSU.
I've got an early prototype in a friend's loft that's been running
continuously since 2004 and still seems OK. But MRD applies... :~)

--
Andy

In article , Mike Tomlinson
writes
En el artículo , Simon T darkangel5@REMOVET
HISBITlineone.net escribió:

What I was curious about though was firstly, was this simply a case of the
old booster developing a fault

My money would be on bad caps in the booster power supply. The age is
about right, and it's been hot recently, which will have hastened the
demise of the booster with it being in the loft.

The one problem-free output is harder to explain away - perhaps it's a
direct feed from the aerial and is not actually amplified.

I've recently started having problems with Freeview signal dropping out
esp at daytime on some channels. As a result of this thread I've swopped
round the outputs from my booster amp and now it's OK - (except for the
(unused) socket which is now fed from the faulty output)

--
bert

bert posted
I've recently started having problems with Freeview signal dropping out
esp at daytime on some channels.

Yes, me too. BBC1 often becomes unwatchable in the morning and early
evening.

As a result of this thread I've swopped round the outputs from my
booster amp and now it's OK - (except for the (unused) socket which is
now fed from the faulty output)

I don't have a booster amp, just a standard loft aerial. We have an 80%
strength signal from the Honiton transmitter, but quality spasmodically
drops below 50 per cent.

--
Les