HDTV - experince (tip) - Melbourne Metro

[Joe G \(Home\)]

Hi All,

Background
===========
I have a little bit of RF and electronics experience and I was called to my
friends house to help fix the HDTV signal problems on ABC(HD). The
complaint was poor signal or no signal and some pixelation (spelling). [I'm
no TV expert].

How could ABC(HD) be poor and the other HD channels and SD channels be OK?
Hmmm I said.

When I turn on the VCR and or the DVD player etc the pixelation got worse
, but most significantly on ABC(HD).
Ahhhh I said, it must be the switch mode power supplies causing
interference.

The problem had recently occurred over the last few months.

- Setup External Analog TV antenna and 2way splitter to another room (all
HDTV signals good in the other room)

Connection
========
The setup had a Belkin surge protector that protected the RF and mains
power.

Hence the antenna RF signal when through the surge protector (probably
arrestor inside).


Theory
========
I thought that since the interference was worse with other power devices
on... I suspected that the RF surge arestor must be
coupling noise/interference in to the RF of the HDTV TV set.

Removing /bypassing the RF surge protection ..... all signals including the
ABC(HD) GOOD ! ;-)

==> Problem Solved <==== (I think - but no RF surge protection).

Comment
=======
Perhaps the signal level to the HDTV set was marginal and the extra
interference triggered a threshold level of noise/interference.


QUESTIONS
=========
Q1
Are digital TV antenna significantly different to Analog TV antenna's in RF
pass bands etc?

Is more signal gain required for digital?

Q2
Can you suggest any HDTV forums that might focus on Melbourne?

Q3
What are your comments about RF surge protection (and earthing etc). Is it
really necessary.
Surely the HDTV set has internal surge protection (it's a well known brand
P..c).

Q4
Do you have any clues , comment or tips you can share?


I welcome your comments.

Thanks in advance

Regs
Joe [not a TV expert]

 

[atec 77]

Hi All,

Background
===========
I have a little bit of RF and electronics experience and I was called to my
friends house to help fix the HDTV signal problems on ABC(HD). The
complaint was poor signal or no signal and some pixelation (spelling). [I'm
no TV expert].

How could ABC(HD) be poor and the other HD channels and SD channels be OK?
Hmmm I said.

When I turn on the VCR and or the DVD player etc the pixelation got worse
, but most significantly on ABC(HD).
Ahhhh I said, it must be the switch mode power supplies causing
interference.

The problem had recently occurred over the last few months.

- Setup External Analog TV antenna and 2way splitter to another room (all
HDTV signals good in the other room)

Connection
========
The setup had a Belkin surge protector that protected the RF and mains
power.

Hence the antenna RF signal when through the surge protector (probably
arrestor inside).


Theory
========
I thought that since the interference was worse with other power devices
on... I suspected that the RF surge arestor must be
coupling noise/interference in to the RF of the HDTV TV set.

Removing /bypassing the RF surge protection ..... all signals including the
ABC(HD) GOOD ! ;-)

==> Problem Solved <==== (I think - but no RF surge protection).

Comment
=======
Perhaps the signal level to the HDTV set was marginal and the extra
interference triggered a threshold level of noise/interference.


QUESTIONS
=========
Q1
Are digital TV antenna significantly different to Analog TV antenna's in RF
pass bands etc?

Is more signal gain required for digital?

Q2
Can you suggest any HDTV forums that might focus on Melbourne?

Q3
What are your comments about RF surge protection (and earthing etc). Is it
really necessary.
Surely the HDTV set has internal surge protection (it's a well known brand
P..c).

Q4
Do you have any clues , comment or tips you can share?


I welcome your comments.

Thanks in advance

Regs
Joe [not a TV expert]

Research the actual frequency of the aerial frequency required you are
using , I expect there is nothing close to a resonant length on the
thing close to that required so it may well need replacing with one more
a-tuned

 

[Phil Allison]

"Joe G (Home)"

Are digital TV antenna significantly different to Analog TV antenna's in
RF pass bands etc?

** Yep.

Digital only antennas ( for metropolitan use) are small - cos they have no
long elements fitted for receiving channels below ch 6. They also cover the
VHF range up to ch 12 which few analogue antennas do - plus the UHF range.

ABC Digital is on VHF ch 12 so can be problematic.

Is more signal gain required for digital?

** Post antenna gain will not help.

But a well sited, high gain antenna designed for digital may be essential
in some locations.


..... Phil

 

[Trevor Wilson]

Hi All,

Background
===========
I have a little bit of RF and electronics experience and I was called
to my friends house to help fix the HDTV signal problems on ABC(HD).
The complaint was poor signal or no signal and some pixelation
(spelling). [I'm no TV expert].

How could ABC(HD) be poor and the other HD channels and SD channels
be OK? Hmmm I said.

When I turn on the VCR and or the DVD player etc the pixelation got
worse , but most significantly on ABC(HD).
Ahhhh I said, it must be the switch mode power supplies causing
interference.

The problem had recently occurred over the last few months.

- Setup External Analog TV antenna and 2way splitter to another room
(all HDTV signals good in the other room)

Connection
========
The setup had a Belkin surge protector that protected the RF and
mains power.

Hence the antenna RF signal when through the surge protector (probably
arrestor inside).


Theory
========
I thought that since the interference was worse with other power
devices on... I suspected that the RF surge arestor must be
coupling noise/interference in to the RF of the HDTV TV set.

Removing /bypassing the RF surge protection ..... all signals
including the ABC(HD) GOOD ! ;-)

==> Problem Solved <==== (I think - but no RF surge protection).

Comment
=======
Perhaps the signal level to the HDTV set was marginal and the extra
interference triggered a threshold level of noise/interference.


QUESTIONS
=========
Q1
Are digital TV antenna significantly different to Analog TV antenna's
in RF pass bands etc?

Is more signal gain required for digital?

Q2
Can you suggest any HDTV forums that might focus on Melbourne?

Q3
What are your comments about RF surge protection (and earthing etc).
Is it really necessary.
Surely the HDTV set has internal surge protection (it's a well known
brand P..c).

Q4
Do you have any clues , comment or tips you can share?


I welcome your comments.

Thanks in advance

Regs
Joe [not a TV expert]

**For HDTV you need the following:

1) A decent antenna and good signal.
2) Decent, quad shield cable. (VERY important).

BTW: Surge protection devices are bullshit.

 

[westom]

Theory
========
I thought that since the interference was worse with other power devices
on... I suspected that the RF surge arestor must be
coupling noise/interference in to the RF of the HDTV TV set.

Removing /bypassing the RF surge protection ..... all signals including the
ABC(HD) GOOD ! ;-)

You have assumed the protector was providing protection, Even its manufacturer numeric specs do not make that claim. And those specs also forget to mention how much it degrades TV signals.

Same reason why cable companies recommend no protector on their cable. Protection must be located when the antenna (cable) enters the building. Better protection means making the connection where protection works - and without any protector. A reduced signal means intermittent loss of the digital signal (pixilation and other noise problems).

That protector would also be a conductor for noise. Noise that otherwise would not get into a cable is connected to the cable by excessive capacitance inside some protectors.

 

[westom]

Q1
Are digital TV antenna significantly different to Analog TV antenna's in RF pass bands etc?

Antenna only understands frequency (and direction) of a radio wave. To an antenna, a digital and an analog signal are same. Only difference between digital and analog is how the modulated signal is demodulated. That is completely and only inside a TV – irrelevant to the antenna.

Why do some hype digital antennas? Because that myth is so profitable. And because so many don’t ask damning questions that would expose a ‘high profit’ retail myth.

 

[Joe G \(Home\)]

Hi All,

Background
===========
I have a little bit of RF and electronics experience and I was called to
my friends house to help fix the HDTV signal problems on ABC(HD). The
complaint was poor signal or no signal and some pixelation (spelling).
[I'm no TV expert].

How could ABC(HD) be poor and the other HD channels and SD channels be
OK? Hmmm I said.

When I turn on the VCR and or the DVD player etc the pixelation got
worse , but most significantly on ABC(HD).
Ahhhh I said, it must be the switch mode power supplies causing
interference.

The problem had recently occurred over the last few months.

- Setup External Analog TV antenna and 2way splitter to another room (all
HDTV signals good in the other room)

Connection
========
The setup had a Belkin surge protector that protected the RF and mains
power.

Hence the antenna RF signal when through the surge protector (probably
arrestor inside).


Theory
========
I thought that since the interference was worse with other power devices
on... I suspected that the RF surge arestor must be
coupling noise/interference in to the RF of the HDTV TV set.

Removing /bypassing the RF surge protection ..... all signals including
the ABC(HD) GOOD ! ;-)

==> Problem Solved <==== (I think - but no RF surge protection).

Comment
=======
Perhaps the signal level to the HDTV set was marginal and the extra
interference triggered a threshold level of noise/interference.


QUESTIONS
=========
Q1
Are digital TV antenna significantly different to Analog TV antenna's in
RF pass bands etc?

Is more signal gain required for digital?

Q2
Can you suggest any HDTV forums that might focus on Melbourne?

Q3
What are your comments about RF surge protection (and earthing etc). Is
it really necessary.
Surely the HDTV set has internal surge protection (it's a well known
brand P..c).

Q4
Do you have any clues , comment or tips you can share?


I welcome your comments.

Thanks in advance

Regs
Joe [not a TV expert]

Research the actual frequency of the aerial frequency required you are
using , I expect there is nothing close to a resonant length on the thing
close to that required so it may well need replacing with one more a-tuned

Yeah, abc digital is 226MHz.

 

[Phil Allison]

"Joe G (Home)"

Yeah, abc digital is 226MHz.

** In reality, ABC Digital transmits THREE signals in the band from 203 to
210 MHz.



.... Phil

 

[atec 77]

Hi All,

Background
===========
I have a little bit of RF and electronics experience and I was called to
my friends house to help fix the HDTV signal problems on ABC(HD). The
complaint was poor signal or no signal and some pixelation (spelling).
[I'm no TV expert].

How could ABC(HD) be poor and the other HD channels and SD channels be
OK? Hmmm I said.

When I turn on the VCR and or the DVD player etc the pixelation got
worse , but most significantly on ABC(HD).
Ahhhh I said, it must be the switch mode power supplies causing
interference.

The problem had recently occurred over the last few months.

- Setup External Analog TV antenna and 2way splitter to another room (all
HDTV signals good in the other room)

Connection
========
The setup had a Belkin surge protector that protected the RF and mains
power.

Hence the antenna RF signal when through the surge protector (probably
arrestor inside).


Theory
========
I thought that since the interference was worse with other power devices
on... I suspected that the RF surge arestor must be
coupling noise/interference in to the RF of the HDTV TV set.

Removing /bypassing the RF surge protection ..... all signals including
the ABC(HD) GOOD ! ;-)

==> Problem Solved <==== (I think - but no RF surge protection).

Comment
=======
Perhaps the signal level to the HDTV set was marginal and the extra
interference triggered a threshold level of noise/interference.


QUESTIONS
=========
Q1
Are digital TV antenna significantly different to Analog TV antenna's in
RF pass bands etc?

Is more signal gain required for digital?

Q2
Can you suggest any HDTV forums that might focus on Melbourne?

Q3
What are your comments about RF surge protection (and earthing etc). Is
it really necessary.
Surely the HDTV set has internal surge protection (it's a well known
brand P..c).

Q4
Do you have any clues , comment or tips you can share?


I welcome your comments.

Thanks in advance

Regs
Joe [not a TV expert]

Research the actual frequency of the aerial frequency required you are
using , I expect there is nothing close to a resonant length on the thing
close to that required so it may well need replacing with one more a-tuned

Yeah, abc digital is 226MHz.

The you need to determine how far off the resonant frequency the
existing aerial is and then replace it with a suitable unit as others
have ( cutting most likely wont work )alluded to

 

[David L. Jones]

"Joe G (Home)"


** Yep.

Digital only antennas ( for metropolitan use) are small - cos they
have no long elements fitted for receiving channels below ch 6. They
also cover the VHF range up to ch 12 which few analogue antennas do - plus
the UHF range.
ABC Digital is on VHF ch 12 so can be problematic.

And there is the log-periodic antenna type that, whilst lower in gain, make
up for it by having a better frequency response and do not need a balun.
So in many cases the log-periodic type can improve your performance.

** Post antenna gain will not help.

But a well sited, high gain antenna designed for digital may be
essential in some locations.

As is good quality RG6 quad shield coax and F connectors. This is usually
the first step in upgrading your antenna system to better support digital.

Dave.

 

[Phil Allison]

"David L. Jones"

And there is the log-periodic antenna type that, whilst lower in gain,
make up for it by having a better frequency response and do not need a
balun.
So in many cases the log-periodic type can improve your performance.

** Think Dave is alluding to one of these:

http://www.academytv.com.au/prod444.htm

Cheap and small - less than 1 metre square.

Conventional Yagi designs give more gain and directionality, but are
somewhat larger and more expensive.




..... Phil

 

[David L. Jones]

"David L. Jones"


** Think Dave is alluding to one of these:

http://www.academytv.com.au/prod444.htm

Cheap and small - less than 1 metre square.

Conventional Yagi designs give more gain and directionality, but are
somewhat larger and more expensive.

Yup.
See:
http://www.aerialsandtv.com/aerials.html#LogPeriodicTheory

I had a noticeable improvement in impulse noise immunity on digital after
installing my log-periodic.

Dave.

 

[Joe G \(Home\)]

Hi All,

Background
===========
I have a little bit of RF and electronics experience and I was called to
my
friends house to help fix the HDTV signal problems on ABC(HD). The
complaint was poor signal or no signal and some pixelation (spelling).
[I'm
no TV expert].

How could ABC(HD) be poor and the other HD channels and SD channels be
OK?
Hmmm I said.

When I turn on the VCR and or the DVD player etc the pixelation got
worse
, but most significantly on ABC(HD).
Ahhhh I said, it must be the switch mode power supplies causing
interference.

The problem had recently occurred over the last few months.

- Setup External Analog TV antenna and 2way splitter to another room (all
HDTV signals good in the other room)

Connection
========
The setup had a Belkin surge protector that protected the RF and mains
power.

Hence the antenna RF signal when through the surge protector (probably
arrestor inside).


Theory
========
I thought that since the interference was worse with other power devices
on... I suspected that the RF surge arestor must be
coupling noise/interference in to the RF of the HDTV TV set.

Removing /bypassing the RF surge protection ..... all signals including
the
ABC(HD) GOOD ! ;-)

==> Problem Solved<==== (I think - but no RF surge protection).

Comment
=======
Perhaps the signal level to the HDTV set was marginal and the extra
interference triggered a threshold level of noise/interference.


QUESTIONS
=========
Q1
Are digital TV antenna significantly different to Analog TV antenna's in
RF
pass bands etc?

Is more signal gain required for digital?

Q2
Can you suggest any HDTV forums that might focus on Melbourne?

Q3
What are your comments about RF surge protection (and earthing etc). Is
it
really necessary.
Surely the HDTV set has internal surge protection (it's a well known
brand
P..c).

Q4
Do you have any clues , comment or tips you can share?


I welcome your comments.

Thanks in advance

Regs
Joe [not a TV expert]

Where in the Melbourne metro is your friend located?
Have they got a clear line-of-sight of Mt Dandenong?
They're not in The Basin, or really close to the foothills somewhere like
that are they?

Near South Land