Welcome to White space filter.com

If you found this page you must be having reception problems with your DTV or ATSC over the air television reception. Our government has changed the licensing of the 700 to 800 MHz frequencies from television to communication devices. These devices are called Television Band Devices or White Space Devices.

At this point in not sure what the name brands will call the devices, or how they work. They could be based on the LTE, WiMax or the 802.22 standard. We do know that these Fixed TVBD’s will have a radiated power of up to 4 watts with portable devices having a 100 mW limit.

You may be looking for a filter Here is my e-comerce web site where I sell TV band filters.

You will need to identify the problem, the first issue is Digital TV channels have what is known as virtual channels. For example ch 2.1 could really be operating on ch 12 go to the table to identify the real channel from the virtual channel Table

Once you know what channel you are watching you can identify what channel to eliminate with a notch filter or low pass filter.

The process to identify the offending source:

Take note of the loss of the digital picture; for example does it blink out every 5 seconds?

Then you will be looking for something that blinks every 5 seconds! The process to identify the problem requires you to use your analog tv tuner inside the TV. You will be looking at the Snow on the analog TV picture. You will be looking for something at the same blink rate =5 seconds.

If this interference is on channels 2-51 procede below

If this interference is on channels 52 or 53 you will need a LPF-49 filter Like This.

If this interference is on channels 54 to 60 you will need a LPF-51 filter Like This.

Now you know the interference from these devices can be seen, it will usually be:

1. Adjacent to a DTV channel you want to watch--- See adjacent below

2. 7 channels above the channel you want to watch --- See 7 channels below

3. 14 or 15 channels above the channel you want to watch --- See 15 channels below

4. All channels are lost --- See all channels below

Adjacent—If one of these devices is operating on a channel + or -, 1 or 2 channels from the channel you are watching It could be overloading the TV tuner inside your TV set. Notching out this channel can be done.

If the problem source is on ch 7 to 13 you need this notch filter

If the problem source is on ch 14 to 51 you need this notch filter

7 Channels above could interfere with the oscillator inside the tuner. There can be two paths for this: The first is through the antenna and can be eliminated with the appropriate filter from My e-comerce site. The second path of interfearence is called Direct pickup and is caused by this transmitter causing a instability inside of the TV tuner. Shielding the tuner is the only cure with a shield Like This or by rotating/ turning the TV away from the interfearence.

15 channels above is what is known as the image frequency. This is a common weakness of common TV tuners. You should be able to filter out the interfering signal with a filter

If the problem source is on ch 7 to 13 you need this notch filter unlikely unless ch5 or 6 is bad

If the problem source is on ch 14 to 51 you need this notch filter

If this source is on channels 52 or 53 you will need a LPF-49 filter Like This Low pass filter.

If this source is on channels 54 to 60 you will need a LPF-51 filter Like This Low pass filter.

If all Channels come and go this is caused by pure overload. The most likely cause is the antenna pre amplifier getting to much signal. Removal of the preamp or getting a better one could resolve the issue. If you do not have a preamp other possible remedies include adding attenuation of 3,6 or 9 dB Like This could help.

Hope this helps

Bill Bennett

Kq6ly@hotmail.com