WiFi Notch Filter?
- Thread starter Forly192
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I'm not sure it's rated that high but the graph looks like it might be. https://www.aliexpress.com/item/LPF...7463-48c3-b54e-0fdb5bc7fb4a&priceBeautifyAB=1
os something like this https://www.123securityproducts.com/lpf-470.html
os something like this https://www.123securityproducts.com/lpf-470.html
I live in a dense WiFi signal area and I need to remove as much RF noise from my surrounding. The biggest is WiFi, followed by cellular.
Before the proliferation of WiFi, I used to be able to pick up a repeater some 30 miles away. Now it barely make it past the noise floor.
So I need dedicated notch filters to really drown out the RF noise from WiFi, LTE, BC FM and shortwave. I have found notch filters for all the others, but I'm having a hard time finding anything for WiFi.
Before the proliferation of WiFi, I used to be able to pick up a repeater some 30 miles away. Now it barely make it past the noise floor.
So I need dedicated notch filters to really drown out the RF noise from WiFi, LTE, BC FM and shortwave. I have found notch filters for all the others, but I'm having a hard time finding anything for WiFi.
Have you ruled out any failures of your equipment, such as Coax or Antenna?
Also have you ruled out the possibility that changes were made to the repeater that you have been monitoring or listening to?
I highly doubt that, given the low-power nature of Wi-Fi, and how far its frequencies are from the VHF range you say you're trying to receive. Unless your Wi-Fi router is right next to your antenna, or someone near you is running an illegal and grossly overpowered Wi-Fi power amp, it's not going to cause interference to VHF.
A better approach to your problem would be to find a ~150MHz bandpass filter, rather than daisychaining a bunch of notch filters, each of which will introduce additional signal loss.
i have seen hf/vhf interference from the router/wifi device itself (cpu noise and such) as well a those darn wall warts !
Only when they are close to the antenna. The range of that sort of thing is a few feet, and can usually be fixed by moving the antenna away from the router or wall wart. If the antenna is outside, the problem goes away.
My antennas are outside and they beg to differ
not to mention my remote HF setup hears stuff from all over the neighborhood
Possibly in older or less expensive gear. Not so much today.
If you have a wall wart generating so much RFI that it is being picked up by an outdoor antenna, then replace it. Most of them have no detectable RFI if the antenna is more than a few feet away.
you guys ought to live where i live
it isnt my stuff making noise
it isnt my stuff making noise
Folks, the OP is looking for 2.4 GHz and 5 GHz notch filters, not better wall warts. Let's get back on topic.
Frankly, I think a bandpass filter for the frequencies of interest sounds like a better approach than a stack of notch filters, but that's up to the OP to decide.
Frankly, I think a bandpass filter for the frequencies of interest sounds like a better approach than a stack of notch filters, but that's up to the OP to decide.
Ubbe
Member
Output from WiFi transmitters are something like 100mW and at 2.4GHz it is filtered out in scanners and receivers to absolut nothing.
It's not a WiFi frequency filter you need.
If you go to ebay and do a search for "low pass filter" you get several filters that cut off higher frequencies above what you receive.
If they will work for you are another matter.
When you monitor 145Mhz the filters in the reciever attenuate everything above 200MHz a lot and should not be possible to get interfered from higher frequencies.
I guess you have the inteference from something else like a LCD/plasma tv, a cpu controlled device like routers, RasberryPi or LED lights.
Get a portable receiver/scanner and try to search for the strongest interfering signal in the band by having the squelch open and search the frequencies and then try to locate the source.
It would help to use a $10 SDR dongle with #SDRsharp and check the spectrum.
/Ubbe
It's not a WiFi frequency filter you need.
If you go to ebay and do a search for "low pass filter" you get several filters that cut off higher frequencies above what you receive.
If they will work for you are another matter.
When you monitor 145Mhz the filters in the reciever attenuate everything above 200MHz a lot and should not be possible to get interfered from higher frequencies.
I guess you have the inteference from something else like a LCD/plasma tv, a cpu controlled device like routers, RasberryPi or LED lights.
Get a portable receiver/scanner and try to search for the strongest interfering signal in the band by having the squelch open and search the frequencies and then try to locate the source.
It would help to use a $10 SDR dongle with #SDRsharp and check the spectrum.
/Ubbe
Kb2Jpd
Member
Sounds like you have an electrical ground but not true rf ground.
Did you sink a ground rod for your hf setup?
Adam Kb2Jpd
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I tried to remove all electrical noise by turning off the main power to the house and the signal was the same, no changes.
That led me to believe that it was WiFi in the neighborhood since the last time I listened to this repeater was a few years back when there were just one or three hotpots around me.
But, it is possible that the repeater was somehow changed, I guess I won't know for sure.
It's also possible that a new broadcast FM station popped up in a nearby town and is overloading the front end of the receiver. I tried an FM notch filter. That didn't change much.
That led me to believe that it was WiFi in the neighborhood since the last time I listened to this repeater was a few years back when there were just one or three hotpots around me.
But, it is possible that the repeater was somehow changed, I guess I won't know for sure.
It's also possible that a new broadcast FM station popped up in a nearby town and is overloading the front end of the receiver. I tried an FM notch filter. That didn't change much.
I'll second the use of a dongle and SDRSharp. It gives you a good visual representation of the RF that is in your area. I did just the same thing to resolve a problem with interference I've been having with wireless microphones.
Kb2Jpd
Member
It is the concenus of the readers that the noise may not be at those microwave frequency but rather induced by the adjacent gear he owns and operates.
There is plenty of gear outside of his residence which may be operating improperly such as oscillating cable amplifiers sending crap up to the 2.4 and 5 GHZ band.
The other thing may be the receiver is receiving stuff on adjacent if frequency.
Time to do some old fashioned detective work.
Adam Kb2Jpd
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