noisy and scrambled pictures with wireless transmitter

[cd090580]

Hi,

I have a wireless video transmitter connected to my digital satellite receiver to I can watch satellite tv in my bedroom.
But I have a big problem, the picture is very noisy and scrambled at some moments. Sometimes it can work several hours ou days without any artifacts.

I even tried putting the receiver and transmitter in the same room to make sure the problem is not due to the house's walls but it's the same.

Here is how it's connected:
Satellite receiver => output 1 => TV, VCR output => wireless transmitter
On the TV => I/O 1 or 2 => wireless receiver.


But I notice a very strange thing: if I put my hand just in front of the receiver's antenner (parabolic antenna), the noise instantly disappeard and the picture becomes very clear without any degradation. It only works with my hand, a sheet of paper, a cd-r box,... doesn't improve or degrade the picture.

I uploaded a collection of several produced noises.
Available here => http://www3.partage-facile.com/1017084-wireless_noise.avi.html

What can I do to make it work ??

[Krispy Kritter]

My first thought would be interference from another source. Without knowing the exact hardware you are using, I don't know the frequency range.

[cd090580]

There are 4 channels (A,B,C and D). All of these produce the same interferences. Main frequency is 2,4 Ghz.

[cd090580]

I don't have any other wireless sources in my home. How can I determine if there are other sources around my house ?

[SingSing]

2.4GHz is where wireless internet aka wi-fi operates.

Since a non-conductive shield work for you, then origami a piece of paper and fix it on the antenna, and run down to the local patent office.

[Krispy Kritter]

Cordless phones also use the 2.4ghz range, which could be you or a neighbor. Most of the newer models use 5.8ghz. If all else fails, get a different wireless transmitter that uses a different freq range.

[Midzuki]

IIRC, microwave ovens also produce 2.4GHz radiation.

[cd090580]

Is there any devices or some king of scanners that can tell me if there are 2,4 Ghz radiations in my home ???

[mikel]

You might try this...

http://www.wlanparts.com/product/WI-SPY?meta=FRG&utm_source=GBASE&utm_medium=CPC&utm_c...&utm_campaign=

[SingSing]

IIRC, microwave ovens also produce 2.4GHz radiation.

God job! I did not figured out where is microwave oven op frequency, until you say so.
Remember the screen behind the oven door is NOT a screen, it is just an attenuator.

To make a home brew 2.4GHz detector, JUST goto your part box, and

Connector a horn antenna, feed into a LNA, then a 2.4GHz band pass filter, AM detector, a 50 OHM load, and measured the voltage across the load, with a voltmeter. Use a calculator and convert voltage to dB ( Hopefully it is actually dBm. )

Or

Buy this for $29.00 : http://www.lessemf.com/mw-oven.html

[Richard_G]

Cordless phones also use the 2.4ghz range

Not in Europe they don't....

If all else fails, get a different wireless transmitter that uses a different freq range.

There aren't any available for domestic use, 2.4GHz (2400-2483MHz is the exact range) is the only band used. The 4 channels are evenly spaced between these band edges, each being around 16-20MHz wide. Microwave ovens operate on a nominal frequency of 2450MHz. WiFi operates between 2400 and 2483MHz. Do these numbers sound familiar? If there is only your own WiFi in the area you can set that at one end of the band and the video sender at the other. If all your neighbours have WiFi chances are the whole band is full and you won't find a free bit of spectrum.