I am going nuts.
We are using a 2.4GHz wireless video broadcaster in our home (Germany,
240V, 50Hz, PAL TV 25fps). It is based in the lower level and
transmits a satellite receiver output to the upper level TV room,
about 25ft away (3x 1ft stone walls in between).
The received video signal has a large regular interference, a
horizonal stripe (about 5% high, small vertical bands with colored
specks, almost white appearance) crawls fast through the picture,
accompanied by a chopping noise, about 8-10 chops per second. The
stripe scrolls fast through the picture, about 2-3 times per second,
downwards.
A classical interference. PAL operates at 25cycles per second, German
power at 50Hz, what does this tell about the interference spectrum/
freq?

Yes, we have a variety of other wireless devices in the house,
including a Fritz! WLAN, 2 2.4GHz phone bases (5 mobile phones),
several wireless weather stations, a Razr cell phone.
I pulled ALL plugs of all known wireless devices, unscrewed fuses
wherever needed, NADA! The noise remains, as strong as before.
I even put all wireless phones into a metal box and carried it out of
the building, still no change.
Meaning that all my wireless devices do NOT have any impact at all,
the other noise is the main problem. WHERE THE HELL IS IT COMING FROM?

The received video signal is rather weak, moving the receiver around
yields interesting spots of "almost" no noise (about 1ft apart).
Interesting to note: the noise gets typically more solid if the
overall picture is better and clear/strong. Meaning if I settle for a
grainy video, then the stripe is almost invisible (yet noticable in
the audio part as the mentioned fast 'chop chop chop' noise)

I am at the end of my wits. Cannot analyze freq sprectrum nor do I
have other tools handy to investigate. Am a left handed physicist, not
an electrical freak, hence my plead for support here!
What could cause this strong interference, a neighbor, the power line,
the antenna from the satellite/cable (even switched off the HF
amplifier for TV)?

What else should I try to isolate the problem? Cut the power line of
all my neighbors?

Thanks a bunch!
michael

wrote:

A classical interference. PAL operates at 25cycles per second, German
power at 50Hz, what does this tell about the interference spectrum/
freq?

If you are using SCART, it's probably the internal tuner output from
your TV crossmodulating with the output from the sender receiver box.
Open up the SCART lead at the TV end and cut pin 19 (composite video
out). Or you may be able to switch this output off in a setup menu.

For a quick check before you do any of this - remove the aerial lead
from the TV. What happens? :-)

--
Adrian C

On Jul 11, 2:30*pm, Adrian C wrote:
wrote:
A classical interference. PAL operates at 25cycles per second, German
power at 50Hz, what does this tell about the interference spectrum/
freq?

If you are using SCART, it's probably the internal tuner output from
your TV crossmodulating with the output from the sender receiver box.
Open up the SCART lead at the TV end and cut pin 19 (composite video
out). Or you may be able to switch this output off in a setup menu.

For a quick check before you do any of this - remove the aerial lead
from the TV. What happens? :-)

--
Adrian C

What about a microwave oven????

Bob Hofmann

wrote:
snip

What else should I try to isolate the problem? Cut the power line of
all my neighbors?

Thanks a bunch!
michael

Sounds suspiciously like what my WiFi router does to my 2.4gig video
link. If you have a laptop with wifi, try checking for a signal in your
area...or ask a friend to bring over his laptop, if not.

jak

"jakdedert" wrote in message
.. .
wrote:
snip

What else should I try to isolate the problem? Cut the power line of
all my neighbors?

Thanks a bunch!
michael

Sounds suspiciously like what my WiFi router does to my 2.4gig video link.
If you have a laptop with wifi, try checking for a signal in your
area...or ask a friend to bring over his laptop, if not.

jak

Could well be from a neighbour's WiFi. As well as my own, I can see three
other networks on my machines, one of which is stronger at one of my
locations, than my own network ! You could try rotating a large saucepan lid
around the video link receiver to see if the interference is minimised at
any point. That will then tell you the direction that it's getting in from.

Arfa

Could well be from a neighbour's WiFi.

I agree, that's the most likely.

Most WiFi access points send out a "beacon" packet every 100
milliseconds or so, even when they have no associated clients - this
is how client systems can "see" them, and send a request-to-associate.

I tried a 2.4 GHz wireless video sender/receiver system a few years
ago, and quite quickly gave up on it. It was bothered by WiFi, by a
2.4-gig frequency-hopping spread spectrum cordless telephone, and by
every microwave oven within half a block.

Between that interference, and the fact that the sender had difficulty
getting a reasonably clean video image through just three sheet-rock
interior walls, I gave it up as a bad job and ran a "composite video
plus stereo audio" cable through the ceiling.

--
Dave Platt AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

wrote:
I am going nuts.
We are using a 2.4GHz wireless video broadcaster in our home (Germany,
240V, 50Hz, PAL TV 25fps). It is based in the lower level and
transmits a satellite receiver output to the upper level TV room,
about 25ft away (3x 1ft stone walls in between).
The received video signal has a large regular interference,

You are the lucky reciever of WIFI data blocks, if possible,
select the highest possible frequency you can get out of
your transmitter.
Been there, done that and solved it, because few people bother
to switch their WIFI to the high frequency channels.

In article , "hr(bob) " wrote:
On Jul 11, 2:30=A0pm, Adrian C wrote:
wrote:
A classical interference. PAL operates at 25cycles per second, German
power at 50Hz, what does this tell about the interference spectrum/
freq?

If you are using SCART, it's probably the internal tuner output from
your TV crossmodulating with the output from the sender receiver box.
Open up the SCART lead at the TV end and cut pin 19 (composite video
out). Or you may be able to switch this output off in a setup menu.

For a quick check before you do any of this - remove the aerial lead
from the TV. What happens? :-)

--
Adrian C

What about a microwave oven????

Bob Hofmann
I bet you have an XBOX360? Their wireless radio in the box that communicates
with the controllers cuases massive interference within the 2.4ghz range.


What i dont get is why doesnt the FCC get after Microsoft on this one????


http://www.itwire.com/content/view/15821/1103/

http://www.gamespot.com/news/6136388.html

http://www.joystiq.
com/2007/12/15/strange-xbox-360-signal-might-affect-wireless-lans/

In article ,
Meat Plow wrote:

I bet you have an XBOX360? Their wireless radio in the box that
communicates with the controllers cuases massive interference within the
2.4ghz range.

What i dont get is why doesnt the FCC get after Microsoft on this one????

As far as the FCC and wireless gear is concerned you can move the source
of the interferrence. I've read many disclaimers on various wireless
apparatus stating to the effect of that. I imagine it's because of the low
power output that there is no tight regulation.

That's about the size of it. The XBOX360, 802.11 b/g network devices,
and 2.4-gig video senders are all certificated under Part 15 of the
FCC regs. They are not individually licensed.

They all have to comply with certain power output rules.

In terms of sharing spectrum, such devices [1] must not interfere with
licensed users of the spectrum, and [2] must accept interference from
any and all devices, both licensed and unlicensed.

In short, as long as it's properly designed and certificated, an
XBOX360 and its controllers has just as much right to use the 2.4 gig
spectrum as do 802.11 network devices and 2.4-gig video senders. None
of these is protected from interference by any other. It's up to
their owners/users to cooperate in order to alleviate any interference
which does occur.

--
Dave Platt AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

On 12 Jul., 20:52, (GMAN) wrote:
In article , "hr(bob) " wrote:



On Jul 11, 2:30=A0pm, Adrian C wrote:
wrote:
A classical interference. PAL operates at 25cycles per second, German
power at 50Hz, what does this tell about the interference spectrum/
freq?

If you are using SCART, it's probably the internal tuner output from
your TV crossmodulating with the output from the sender receiver box.
Open up the SCART lead at the TV end and cut pin 19 (composite video
out). Or you may be able to switch this output off in a setup menu.

For a quick check before you do any of this - remove the aerial lead
from the TV. What happens? :-)

--
Adrian C

What about a microwave oven????

Bob Hofmann

I bet you have an XBOX360? Their wireless radio in the box that communicates
with the controllers cuases massive interference within the2.4ghzrange.

What i dont get is why doesnt the FCC get after Microsoft on this one????

http://www.itwire.com/content/view/15821/1103/

http://www.gamespot.com/news/6136388.html

http://www.joystiq.
com/2007/12/15/strange-xbox-360-signal-might-affect-wireless-lans/- Zitierten Text ausblenden -

- Zitierten Text anzeigen -

Actually I DO NOT have an XBOX 8-( - and I don't miss it 8-)
And remember that I unplugged all devices and also pulled breakers
where needed? I literally sat in the dark with only the TV sets, Sat
receiver and xmitter working.

But I DO have success, sort of:
the transmitter allows to select 4 different broadcast channels, and
in one (D, the highest?) I noticed that the wide speckled and running
bar disappeared. It was replaced by 2 very narrow and absolutely
static ones! That was actually good news, as it was a DIFFERENT
interference, one I quickly identified as being from my own wireless
base station, located in the same room as the 2.4GHz receiver. That
one can be unplugged anytime; also I am considering to disable/cut the
transmitter or antenna - the base is not actively used, it only serves
as a charger for one cordless phone. It produces a very sharp, whitish
bar, in synch with the receiver for some reason (overtone or fraction
of the xmit frequency I suppose?), no audio interference noticable.
I am quite convinced that the other broad noise is indeed from a
neighbor's WiFi/WLAN system. What is baffling is that the plentitude
of my own wireless devices (with the exception of the one phone base
in the same room) have absolutely no impact on the xmitter/receiver
signal, and this ******* HAS, from 100ft away, through several 1foot
mason walls.
Anyways - thanks for the ideas, hints and suggestions, highly
appreciated!
michael

In article , Meat Plow wrote:
On Sat, 12 Jul 2008 18:52:33 +0000, GMAN wrote:

In article
,
"hr(bob) " wrote:
On Jul 11, 2:30=A0pm, Adrian C wrote:
wrote:
A classical interference. PAL operates at 25cycles per second, German
power at 50Hz, what does this tell about the interference spectrum/
freq?

If you are using SCART, it's probably the internal tuner output from
your TV crossmodulating with the output from the sender receiver box.
Open up the SCART lead at the TV end and cut pin 19 (composite video
out). Or you may be able to switch this output off in a setup menu.

For a quick check before you do any of this - remove the aerial lead
from the TV. What happens? :-)

--
Adrian C

What about a microwave oven????

Bob Hofmann
I bet you have an XBOX360? Their wireless radio in the box that
communicates with the controllers cuases massive interference within the
2.4ghz range.


What i dont get is why doesnt the FCC get after Microsoft on this one????

As far as the FCC and wireless gear is concerned you can move the source
of the interferrence. I've read many disclaimers on various wireless
apparatus stating to the effect of that. I imagine it's because of the low
power output that there is no tight regulation.

Being a class B computing device, it cannot and must not by law cause
interferance with other items.

In article , (Dave Platt) wrote:
In article ,
Meat Plow wrote:

I bet you have an XBOX360? Their wireless radio in the box that
communicates with the controllers cuases massive interference within the
2.4ghz range.

What i dont get is why doesnt the FCC get after Microsoft on this one????

As far as the FCC and wireless gear is concerned you can move the source
of the interferrence. I've read many disclaimers on various wireless
apparatus stating to the effect of that. I imagine it's because of the low
power output that there is no tight regulation.

That's about the size of it. The XBOX360, 802.11 b/g network devices,
and 2.4-gig video senders are all certificated under Part 15 of the
FCC regs. They are not individually licensed.

They all have to comply with certain power output rules.

In terms of sharing spectrum, such devices [1] must not interfere with
licensed users of the spectrum, and [2] must accept interference from
any and all devices, both licensed and unlicensed.

In short, as long as it's properly designed and certificated, an
XBOX360 and its controllers has just as much right to use the 2.4 gig
spectrum as do 802.11 network devices and 2.4-gig video senders. None
of these is protected from interference by any other. It's up to
their owners/users to cooperate in order to alleviate any interference
which does occur.

But the 360 cannot **** all over every bit of that 2.4ghz spectrum!!!!


Also if there is a ham radio operator nearby and he gets interference on his
gear from your 360 or other device , he has recourse thru the courts and the
FCC to have you not use your device anymore.

In article , " wrote:
On 12 Jul., 20:52, (GMAN) wrote:
In article
, "hr(bob)
" wrote:



On Jul 11, 2:30=A0pm, Adrian C wrote:
wrote:
A classical interference. PAL operates at 25cycles per second, German
power at 50Hz, what does this tell about the interference spectrum/
freq?

If you are using SCART, it's probably the internal tuner output from
your TV crossmodulating with the output from the sender receiver box.
Open up the SCART lead at the TV end and cut pin 19 (composite video
out). Or you may be able to switch this output off in a setup menu.

For a quick check before you do any of this - remove the aerial lead
from the TV. What happens? :-)

--
Adrian C

What about a microwave oven????

Bob Hofmann

I bet you have an XBOX360? Their wireless radio in the box that communicates
with the controllers cuases massive interference within the2.4ghzrange.

What i dont get is why doesnt the FCC get after Microsoft on this one????

http://www.itwire.com/content/view/15821/1103/

http://www.gamespot.com/news/6136388.html

http://www.joystiq.
com/2007/12/15/strange-xbox-360-signal-might-affect-wireless-lans/-
Zitierten Text ausblenden -

- Zitierten Text anzeigen -

Actually I DO NOT have an XBOX 8-( - and I don't miss it 8-)
And remember that I unplugged all devices and also pulled breakers
where needed? I literally sat in the dark with only the TV sets, Sat
receiver and xmitter working.

But I DO have success, sort of:
the transmitter allows to select 4 different broadcast channels, and
in one (D, the highest?) I noticed that the wide speckled and running
bar disappeared. It was replaced by 2 very narrow and absolutely
static ones! That was actually good news, as it was a DIFFERENT
interference, one I quickly identified as being from my own wireless
base station, located in the same room as the 2.4GHz receiver. That
one can be unplugged anytime; also I am considering to disable/cut the
transmitter or antenna - the base is not actively used, it only serves
as a charger for one cordless phone. It produces a very sharp, whitish
bar, in synch with the receiver for some reason (overtone or fraction
of the xmit frequency I suppose?), no audio interference noticable.
I am quite convinced that the other broad noise is indeed from a
neighbor's WiFi/WLAN system. What is baffling is that the plentitude
of my own wireless devices (with the exception of the one phone base
in the same room) have absolutely no impact on the xmitter/receiver
signal, and this ******* HAS, from 100ft away, through several 1foot
mason walls.
Anyways - thanks for the ideas, hints and suggestions, highly
appreciated!
michael


Do you live close to a microwave tower or amateur radio operator?

As Bob mentions, this is most likely to be caused by a microwave oven,
especially if it continues for a few minutes then stops completely. There's
nothing you can do except change the channel used for your video sender to
try and minimise it, use more directional aerials, or use a video sender
that uses a different band.

Regards,
Gary