RFI Between Radio, Amp & Wireless Mouse

[Yankee]

Just wanted to share my successful fix for curing radio interference from my wireless mouse and keyboard to the radio. I would hit a key or move the mouse and hear static on the 2985dx. Even worse, if I had the amp on and keyed up, the mouse would freeze, the computer would lock up and not even a Ctrl + Alt + Del would do it. I would have to hit the reset button.

Today, I went to the hardware store and bought a 2 foot by 3 foot piece of aluminum mesh window screen and just stood it up on my desk so it was between the mouse, keyboard, wireless USB antenna and the radio, and tested it. It works perfectly, out of the box. Just saying.

 

[Captain Kilowatt]

It would have to be grounded to be effective. If not then it was just a fluke and it could reoccur any time. Best way to prevent that type of RFI is to check the frequency the wireless stuff operates. A lot of wireless mouse/keyboards etc still use 27 MHz.

 

[Yankee]

It's not grounded and it's not a fluke. It's worked all afternoon within inches of the radio and nothing. Before the screen, one click of the Mic and bam, lockup, restart.

Do you know how the screen in the front of a microwave oven works? Simplified, the holes are too small for the radio waves to get through, so is the screen mesh size. It's not absorbing or grounding them, it's just blocking them.

 

[AudioShockwav]

Simplified, the holes are too small for the radio waves to get through, so is the screen mesh size. It's not absorbing or grounding them, it's just blocking them.

op: op: op: op: op: op: op: op: op:



73
Jeff

 

[9C1Driver]

It's not grounded and it's not a fluke. It's worked all afternoon within inches of the radio and nothing. Before the screen, one click of the Mic and bam, lockup, restart.

Do you know how the screen in the front of a microwave oven works? Simplified, the holes are too small for the radio waves to get through, so is the screen mesh size. It's not absorbing or grounding them, it's just blocking them.

:hea:laugh::headbang:laugh:dbang

 

[Yankee]

You guys are too easy. Try and work it out, you'll get there.

Just don't tell me it don't work.

 

[Mudfoot]

 

[jessejamesdallas]

op:op:op:op:op:op:op:op:op:op:op:op:op:op:op:op:op:

 

[Hc714]

How Is Seeing Related to Wavelength?


Can you see atoms by looking through a visible-light microscope?
Why don't microwaves escape through the holes in a microwave oven's door? It is impossible to use electromagnetic radiation to "see" an object if the wavelength of the radiation is larger than that object. Therefore, you cannot see atoms by using visible light, because atoms are much smaller than visible-light wavelengths. Visible-light waves range from 0.4 to 0.7 micrometer (4000 to 7000 angstroms), whereas an atom is only a few angstroms in size. For the same reason, microwaves, also a kind of electromagnetic radiation, don't escape through the holes in the microwave oven door. The holes are smaller than the wavelength of microwaves, which measure about 120 millimeters (or 12 centimeters). Therefore, the microwaves don't "see" the holes. But visible light, which has much smaller wavelengths, can easily pass through the holes. So we can look through the holes and see the food cooking.

 

[9C1Driver]

How Is Seeing Related to Wavelength?


Can you see atoms by looking through a visible-light microscope?
Why don't microwaves escape through the holes in a microwave oven's door? It is impossible to use electromagnetic radiation to "see" an object if the wavelength of the radiation is larger than that object. Therefore, you cannot see atoms by using visible light, because atoms are much smaller than visible-light wavelengths. Visible-light waves range from 0.4 to 0.7 micrometer (4000 to 7000 angstroms), whereas an atom is only a few angstroms in size. For the same reason, microwaves, also a kind of electromagnetic radiation, don't escape through the holes in the microwave oven door. The holes are smaller than the wavelength of microwaves, which measure about 120 millimeters (or 12 centimeters). Therefore, the microwaves don't "see" the holes. But visible light, which has much smaller wavelengths, can easily pass through the holes. So we can look through the holes and see the food cooking.

Hey hey hey now come on now, let that man believe it works already.

He has a chance to sell this creation to Radiohacktive radios for a new "mod" cure for RF bleedover. It's right up there with the super duper whack pack phase III. LOLOLOLOLOLOL

 

[Yankee]

Only morons argue with the facts. The fact is, the screen works, and until you try it for yourself, you are never going to really know. Maybe take all that tinfoil off your heads and try that. It should also block RFI and you all have proven it's wasted on your heads anyway.

 

[Captain Kilowatt]

I am going to say it more than likely is reflecting the RF rather than acting as a shield. Only a grounded metal screen can act as a shield as the RF has to have some place to go. It could be acting as a passive reflector however. Sometimes even just rearranging things on the operating desk can do the same thing. I had a DSP amp/speaker that would not work in one location but would in another. That screen in the window of a microwave IS grounded BTW and yes you were correct about the hole size being too small related to wavelength.

 

[Yankee]

Yes, reflection rather than just blocking is more logical. I do not think it absorbs them, although it might. But without grounding, it would charge up. Maybe it does, then leaks off slowly. I mean, it's not like I am overworking it by talking for long stretches.

This morning, I took a closer look, and I can not see anywhere where the screen touches metal. The desk is walnut. The screen has a memory roll, from when it was rolled up. I duct taped the two edges where it was cut off the roll, the other two are just rolled and looks like pressed. It's just sitting there, standing on it's own in sort of a half circle around the radio. Heck, let me get a picture.

I still need to fine tune it to size, so it's not in my way but still works. Probably just fold it in half so it's not as tall. I do wish I had a RF Meter though.

 

[AudioShockwav]

Yankee, thanks for letting us have some fun WITH you, Hats off to you for keeping an open mind.
What you are thinking of is called a Faraday cage.
And yes I would think it "might" be reflecting some RF, but it would be better ( and look better ) if you can stop it at the source.
I do not know what else you have tried, but you very well could get by with some ferrite chokes snapped on the cables going into and out of your PC and other equipment that is sitting on your desk next to your station.
Make sure everything related to your station is grounded well.
Many Ham radios, power supplies and Amps have a grounding lugs on the back of them just for this, and CB stuff can suffer the same problems.
My Yaesu and Ameritron are sitting here right next to my PC with no problems.
You can get snap on chokes from RS for cheap, might want to give it a try.
You can use a Field strength meter, often found on inexpensive SWR/power meters to see if you got a lot of RF floating around in the shack.
And Again, Thanks for having good humor

73
Jeff

 

[Yankee]

I got a laugh out of finding out so many people who "know" radio stuff, never heard of the microwave screen thing, except Hc714. I cheated though, when I still drove truck, I had a pickup at the Amana plant over in Iowa one time, and asked one of the people there what it was that stopped the radiation. And got a dumbed down explanation about waves. I mean, who knew?

Snap on Ferrites were one of the first things I bought, even before I got the big black box. I have them everywhere around my desk, and most wires have them on each end and the longer ones, in the middle. Also all the coax jumpers and antenna lead. I did this from fear of bleed over on my neighbors and them complaining to the Camp Nazi. We are not allowed outside antennas here and I do have a dipole up out there, which he hasn't seen yet. LOL

Of course, there is nowhere to put them on the mouse or keyboard, but I have doubled up on the USB fed wireless antenna transceiver. What it boils down to is, the screen was a last resort. I find the wireless stuff to valuable in my paying work to switch back. [I even ordered a new wired keyboard and mouse from Newegg, and it should be here today.] Now it will be my backup, cause this screen works so good and it's not that much trouble, that I will keep using it. When I get a meter that can read the RFI, I might find that this even reduces the radiation I am getting.

Everything is grounded, physically. I have a 5' surplus military helicopter grounding one inch wide and silvered ribbon going from the radio ground, the power supply, and the amp, and out the window to a 20' buried iron pipe. I couldn't think of anything else to do.

I have tested the screen by putting the mouse and keyboard right up against the screen and with the radio and amp turned on, I key up and nothing. No interference, nor any from the keyboard or mouse back into the radio. Short of getting that RFI meter, all I can say is, it works.