A Home cinema forum. HomeCinemaBanter

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » HomeCinemaBanter forum » Home cinema newsgroups » UK digital tv
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

Dumb question: aerial connections to TV



 
 
Thread Tools Display Modes
  #1  
Old September 30th 18, 01:17 PM posted to uk.tech.digital-tv
Another John
external usenet poster
 
Posts: 66
Default Dumb question: aerial connections to TV

Sorry for interrupting this august body with a question so simple but ...

Our TV (Sony Bravia) gets its aerial feed via the PVR (Humax Fox T2).

Owing to its continuing Green Screen problems, the Humax is frequently
powered off (via the switch on the back of the box).

The TV picture then degrades, until lost completely, so we have to
switch the Humax back on.

My dumb question: why does the aerial need the power on, to connect
through to the TV?

Cheers chaps
John
  #2  
Old September 30th 18, 02:34 PM posted to uk.tech.digital-tv
Indy Jess John
external usenet poster
 
Posts: 1,384
Default Dumb question: aerial connections to TV

On 30/09/2018 13:17, Another John wrote:
Sorry for interrupting this august body with a question so simple but ...

Our TV (Sony Bravia) gets its aerial feed via the PVR (Humax Fox T2).

Owing to its continuing Green Screen problems, the Humax is frequently
powered off (via the switch on the back of the box).

The TV picture then degrades, until lost completely, so we have to
switch the Humax back on.

My dumb question: why does the aerial need the power on, to connect
through to the TV?

Cheers chaps
John


The Humax takes the signal in, looks for the channels it knows about so
that it can warn you of new ones, then regenerates the aerial signal so
that it passes on to the TV. When working properly, the Humax will
slightly amplify the output signal so that the TV gets a slightly
stronger signal.

If you turn off the Humax power, it cannot regenerate the signal for the
TV so that the wire going into the TV goes dead. The Humax power supply
has a small reserve of power in its capacitors, which is why the picture
degrades before disappearing.

If you have a strong signal, you might get away with a 2-way splitter on
the aerial wire, one output going to the TV and the other to the Humax.
If you have a weaker signal, then a signal booster with 2 or more
output ports will allow you to connect one output to the TV and the
other to the Humax. Either solution will give you a signal to the TV
whether the Humax is on or off. What you won't be able to do is take
the Humax playback output as an RF channel down the aerial cable, but
you probably were not doing that anyway; the normal connection method
will be either HDMI or SCART.

Jim

  #3  
Old September 30th 18, 02:56 PM posted to uk.tech.digital-tv
Yellow[_3_]
external usenet poster
 
Posts: 160
Default Dumb question: aerial connections to TV

In article , lalaw44
@hotmail.com says...

Sorry for interrupting this august body with a question so simple but ...

Our TV (Sony Bravia) gets its aerial feed via the PVR (Humax Fox T2).

Owing to its continuing Green Screen problems, the Humax is frequently
powered off (via the switch on the back of the box).

The TV picture then degrades, until lost completely, so we have to
switch the Humax back on.

My dumb question: why does the aerial need the power on, to connect
through to the TV?

Cheers chaps
John


Because the Humax contains a powered splitter so each device gets more
than half of the signal that comes from the aerial.

The alternative is to run a separate aerial lead to your TV and Humax.
You can use a passive device if you have a strong enough signal or you
can buy a powered unit.

I have this one for example -

https://www.amazon.co.uk/Philex-Way-...dp/B00DB22ZTI/
  #4  
Old September 30th 18, 04:43 PM posted to uk.tech.digital-tv
R. Mark Clayton[_2_]
external usenet poster
 
Posts: 732
Default Dumb question: aerial connections to TV

On Sunday, 30 September 2018 14:56:39 UTC+1, Yellow wrote:
In article , lalaw44
@hotmail.com says...

Sorry for interrupting this august body with a question so simple but ....

Our TV (Sony Bravia) gets its aerial feed via the PVR (Humax Fox T2).

Owing to its continuing Green Screen problems, the Humax is frequently
powered off (via the switch on the back of the box).

The TV picture then degrades, until lost completely, so we have to
switch the Humax back on.

My dumb question: why does the aerial need the power on, to connect
through to the TV?

Cheers chaps
John


Because the Humax contains a powered splitter so each device gets more
than half of the signal that comes from the aerial.


I had a similar problem with a satellite receiver.


The alternative is to run a separate aerial lead to your TV and Humax.
You can use a passive device if you have a strong enough signal or you
can buy a powered unit.


If the signal is good you can use a resistive splitter. ~-4.5dB £1 pound shop

Less good and you can use a reactive splitter. -3dB £4 "Maplins"

Less good still and you can use a switch ~-0.3dB. £2. TV place.

Amp' unlikely to be required unless signal is marginal.


I have this one for example -

https://www.amazon.co.uk/Philex-Way-...dp/B00DB22ZTI/


  #5  
Old September 30th 18, 05:18 PM posted to uk.tech.digital-tv
NY
external usenet poster
 
Posts: 1,495
Default Dumb question: aerial connections to TV

"R. Mark Clayton" wrote in message
...
If the signal is good you can use a resistive splitter. ~-4.5dB £1 pound
shop

Less good and you can use a reactive splitter. -3dB £4 "Maplins"

Less good still and you can use a switch ~-0.3dB. £2. TV place.

Amp' unlikely to be required unless signal is marginal.


I live in an area that has 62 dBuV/m according to
http://www.macfh.co.uk/JavaJive/Audi...lculator.shtml
which is fairly good but not brilliant. The aerial will feed one device (TV,
PVR, USB adaptor) without any problems. With a simple splitter (not sure
whether it's resistive or reactive) all multiplexes except COM7 and COM8 are
fine; I've even managed to cascade two splitters to give a total of three
outputs and they are fine (except COM7/8). But the PVR is dramatically worse
than anything else, even when it is fed as the output of the first
splitter - ie with 4.5 dB loss rather than 9 dB loss. The TV which is
daisy-chained off the PVR's aerial feed is OK, so evidently the PVR needs a
much stronger signal than anything else.

An amplified splitter (amplifier with four outputs) feeds everything fine.
That cost about £15 on Amazon.

  #6  
Old September 30th 18, 05:38 PM posted to uk.tech.digital-tv
Java Jive[_3_]
external usenet poster
 
Posts: 1,638
Default Dumb question: aerial connections to TV

On 30/09/2018 17:18, NY wrote:

I live in an area that has 62 dBuV/m according to
http://www.macfh.co.uk/JavaJive/Audi...lculator.shtml
which is fairly good but not brilliant.


The calculation used on my site is done by a combination of client-side
(in other words, browser) JavaScript and server-side Python script, and
must of necessity be simple enough to return a prediction within a
realistic time to be useful. Accordingly the UK Transmitter Help
section says: "In particular, signal levels given here should be
regarded as likely relative rather than absolute". In other words,
where there is a choice of possible transmitters to align to, it's
probably fairly good at comparing the likely relative strengths of their
signals to give you an idea of which is likely to be the best, but I'd
want to see the output of an analyser or equivalent professional
equipment before I relied on the actual numerical figures given.
  #7  
Old September 30th 18, 05:58 PM posted to uk.tech.digital-tv
Yellow[_3_]
external usenet poster
 
Posts: 160
Default Dumb question: aerial connections to TV

In article ,
says...

On Sunday, 30 September 2018 14:56:39 UTC+1, Yellow wrote:
In article , lalaw44
@hotmail.com says...

Sorry for interrupting this august body with a question so simple but ...

Our TV (Sony Bravia) gets its aerial feed via the PVR (Humax Fox T2).

Owing to its continuing Green Screen problems, the Humax is frequently
powered off (via the switch on the back of the box).

The TV picture then degrades, until lost completely, so we have to
switch the Humax back on.

My dumb question: why does the aerial need the power on, to connect
through to the TV?

Cheers chaps
John


Because the Humax contains a powered splitter so each device gets more
than half of the signal that comes from the aerial.


I had a similar problem with a satellite receiver.


The alternative is to run a separate aerial lead to your TV and Humax.
You can use a passive device if you have a strong enough signal or you
can buy a powered unit.


If the signal is good you can use a resistive splitter. ~-4.5dB 1 pound shop

Less good and you can use a reactive splitter. -3dB 4 "Maplins"


Maplins? Didn't they go bust.



Less good still and you can use a switch ~-0.3dB. 2. TV place.

Amp' unlikely to be required unless signal is marginal.


I have this one for example -

https://www.amazon.co.uk/Philex-Way-...dp/B00DB22ZTI/


  #8  
Old September 30th 18, 06:31 PM posted to uk.tech.digital-tv
Davey
external usenet poster
 
Posts: 2,325
Default Dumb question: aerial connections to TV

On Sun, 30 Sep 2018 14:34:49 +0100
Indy Jess John wrote:

On 30/09/2018 13:17, Another John wrote:
Sorry for interrupting this august body with a question so simple
but ...

Our TV (Sony Bravia) gets its aerial feed via the PVR (Humax Fox
T2).

Owing to its continuing Green Screen problems, the Humax is
frequently powered off (via the switch on the back of the box).

The TV picture then degrades, until lost completely, so we have to
switch the Humax back on.

My dumb question: why does the aerial need the power on, to connect
through to the TV?

Cheers chaps
John


The Humax takes the signal in, looks for the channels it knows about
so that it can warn you of new ones, then regenerates the aerial
signal so that it passes on to the TV. When working properly, the
Humax will slightly amplify the output signal so that the TV gets a
slightly stronger signal.

If you turn off the Humax power, it cannot regenerate the signal for
the TV so that the wire going into the TV goes dead. The Humax power
supply has a small reserve of power in its capacitors, which is why
the picture degrades before disappearing.

If you have a strong signal, you might get away with a 2-way splitter
on the aerial wire, one output going to the TV and the other to the
Humax. If you have a weaker signal, then a signal booster with 2 or
more output ports will allow you to connect one output to the TV and
the other to the Humax. Either solution will give you a signal to
the TV whether the Humax is on or off. What you won't be able to do
is take the Humax playback output as an RF channel down the aerial
cable, but you probably were not doing that anyway; the normal
connection method will be either HDMI or SCART.

Jim


Here, I am within a few miles of Tacolneston, and I can drive two PVRs
and a TV set using only splitters. I have a booster available if I need
it, but so far, it just sits in a box.

--
Davey.
  #9  
Old September 30th 18, 07:14 PM posted to uk.tech.digital-tv
R. Mark Clayton[_2_]
external usenet poster
 
Posts: 732
Default Dumb question: aerial connections to TV

On Sunday, 30 September 2018 17:58:32 UTC+1, Yellow wrote:
In article ,
says...

On Sunday, 30 September 2018 14:56:39 UTC+1, Yellow wrote:
In article , lalaw44
@hotmail.com says...

Sorry for interrupting this august body with a question so simple but ...

Our TV (Sony Bravia) gets its aerial feed via the PVR (Humax Fox T2).

Owing to its continuing Green Screen problems, the Humax is frequently
powered off (via the switch on the back of the box).

The TV picture then degrades, until lost completely, so we have to
switch the Humax back on.

My dumb question: why does the aerial need the power on, to connect
through to the TV?

Cheers chaps
John

Because the Humax contains a powered splitter so each device gets more
than half of the signal that comes from the aerial.


I had a similar problem with a satellite receiver.


The alternative is to run a separate aerial lead to your TV and Humax..
You can use a passive device if you have a strong enough signal or you
can buy a powered unit.


If the signal is good you can use a resistive splitter. ~-4.5dB £1 pound shop

Less good and you can use a reactive splitter. -3dB £4 "Maplins"


Maplins? Didn't they go bust.


Yes that's why they were in inverted comma's - not sure where you would go now - local RS trade counter if they will serve you?

OTOH
https://www.screwfix.com/p/labgear-2...pass-all-ports £4



Less good still and you can use a switch ~-0.3dB. £2. TV place.

Amp' unlikely to be required unless signal is marginal.


I have this one for example -

https://www.amazon.co.uk/Philex-Way-...dp/B00DB22ZTI/


  #10  
Old September 30th 18, 08:19 PM posted to uk.tech.digital-tv
Bill Wright[_3_]
external usenet poster
 
Posts: 2,949
Default Dumb question: aerial connections to TV

On 30/09/2018 16:43, R. Mark Clayton wrote:

If the signal is good you can use a resistive splitter. ~-4.5dB £1 pound shop


More like 5 to 8dB

Less good and you can use a reactive splitter. -3dB £4 "Maplins"


Inductive splitter. 4dB.

Less good still and you can use a switch ~-0.3dB. £2. TV place.


Switch losses can be 2dB. Daft to use a switch. Just gets left turned
the wrong way and you lose a recording.

Bill
 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Dumb aerial question Pandora UK digital tv 3 February 2nd 05 07:25 PM
Another dumb question. Gonzo High definition TV 0 February 15th 04 05:00 PM
dumb NBA all-star Question Mark Garceau High definition TV 1 February 15th 04 03:09 PM
connections, connections! dave UK home cinema 3 December 3rd 03 05:40 PM
Connections Connections Connections geo Home theater (general) 1 August 20th 03 08:55 AM


All times are GMT +1. The time now is 09:01 AM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
Copyright 2004-2018 HomeCinemaBanter.
The comments are property of their posters.