lead sheeting inside/outside electronics for emi rfi?

TRADERXFAN · « **on:** 21 Oct 2009, 04:52 pm »

Just curious if there would be any benefit to incorporate very thin lead sheets into or onto electronic components as a tweak? Maybe to isolate certain areas internally, or components from interference?

I see a lot about ERS cloth added in mod's, and chassis dampening material. Lead sheets, intuitively, seem like a combo. I know its not PC to use.... but this is the lab!

-Tony

Bill Baker · « **Reply #1 on:** 21 Oct 2009, 05:04 pm »

Will it work? Yes. I would give it a thin coat of paint or something to seal it if you are going to be moving it around alot placing components on it.

Also be aware that it will effect the sound of the component as it will be a very heavy damping material.

Just be sure not to chew on it

Dan Banquer · « **Reply #2 on:** 21 Oct 2009, 05:41 pm »

Quote from: TRADERXFAN on 21 Oct 2009, 04:52 pm

Just curious if there would be any benefit to incorporate very thin lead sheets into or onto electronic components as a tweak? Maybe to isolate certain areas internally, or components from interference?

I see a lot about ERS cloth added in mod's, and chassis dampening material. Lead sheets, intuitively, seem like a combo. I know its not PC to use.... but this is the lab!

-Tony

Are we shielding from radioactive sources? I can't think of any other reason to use lead other than adding extra weight.
Regards;
Dan Banquer

JimJ · « **Reply #3 on:** 21 Oct 2009, 06:07 pm »

Quote from: TRADERXFAN on 21 Oct 2009, 04:52 pm

Just curious if there would be any benefit to incorporate very thin lead sheets into or onto electronic components as a tweak? Maybe to isolate certain areas internally, or components from interference?

I see a lot about ERS cloth added in mod's, and chassis dampening material. Lead sheets, intuitively, seem like a combo. I know its not PC to use.... but this is the lab!

-Tony

I'd be concerned about the cables picking up RFI before putting a Faraday cage around the equipment. I don't think we have to worry about an EMP too much

art · « **Reply #4 on:** 21 Oct 2009, 06:09 pm »

What kind of metal, and how is needed, depends a great deal on the frequency range that you are concerned about.

Pat

TRADERXFAN · « **Reply #5 on:** 21 Oct 2009, 07:01 pm »

Thanks for the feedback.

Case closed...

Scottdazzle · « **Reply #6 on:** 21 Oct 2009, 09:11 pm »

Maybe you should try Verastar damping sheets. I copied this from their website (I hope I'm not breaking any copyright laws!).

Verastarr StarrDamp CS Vibration Damping Sheets are designed to help reduce resonance and vibration as well as shield the component from stray RFI and EMI. StarrDamp CS sheets consist of a thin piece of pure copper for RFI/EMI shielding and a layer of vibration/resonance damping compound. The sheets are adhesive backed for easy application, which involves opening up your component's chassis and placing the sheets wherever there is room on the sheet metal.

$25.00 for the normal StarrDamp CS kit (includes five 2" x 7" sheets).

$35.00 for the large StarrDamp CS kit (includes five 2" x 7" sheets and an extra 9" x 10" sheet for inner lids)

Speedskater · « **Reply #7 on:** 21 Oct 2009, 11:33 pm »

For RFI shielding almost any metal will do. Copper, aluminum or steel will be fine and thickness won't be much of a factor.
Lead is not magnetic nor is stainless steel, neither will do much for EMI.
The best thing for EMI is mu-metal but it's hard to find and expensive. So for EMI just use any soft steel and the thicker the better.

Bob in St. Louis · « **Reply #8 on:** 22 Oct 2009, 12:23 am »

Cast iron is cheap, readily available, easily sandable, paintable and workable, also isn't poisonous. In fact, it's not only good for you, your body needs it.
1/4" plate would be great for building boxes out of. 1/2" would be better.
RFI/EMI is one thing, but if we start having problems with EMP, I'll stop posting on forums.

Bob

art · « **Reply #9 on:** 22 Oct 2009, 04:43 am »

Quote from: Speedskater on 21 Oct 2009, 11:33 pm

For RFI shielding almost any metal will do. Copper, aluminum or steel will be fine and thickness won't be much of a factor.
Lead is not magnetic nor is stainless steel, neither will do much for EMI.
The best thing for EMI is mu-metal but it's hard to find and expensive. So for EMI just use any soft steel and the thicker the better.

Mu-metal is not used for EMI. Unless "EMI" means low-frequency magnetic fields. Most people who work in EMI compliance worry about other matters. And yes, thickness and material type does matter, depending on the frequency range of interest.

Pat

JimJ · « **Reply #10 on:** 22 Oct 2009, 05:35 am »

Quote

but if we start having problems with EMP, I'll stop posting on forums.

...So will pretty much everyone else

Browntrout · « **Reply #11 on:** 22 Oct 2009, 08:25 am »

The use of lead is a good idea in my opinion, the only thing that will stop or slow down Gamma radiation is a decent thickness of lead. The effect of Gamma radiation upon the transistor has been studied and has been found to break down the boundries between the material layers (NPN or PNP) rsulting in noticably reduced service life of transistors. Also I believe that very small integrated circuits would be effected, with the continual reduction in size of components (now at around 100um for some) the power of Gamma radiatio to cause spurious results in digital circuits is more probable.
I have wondered myself about whether it would be possible to hear the difference when a vacuum tube is surrounded by say 2.5cm of lead as to my mind the operation of a valve is more susceptable to the degrading effect of this most powerfull form of ambient rediation.
Also there are hardened components that were primarily designed for use in reactors and high radiation environments such as space, these have different constructio to normal transistors/components to prevent radiation from affecting their performance. As to whether they happen to sound better in Hifi I don't know it would certainly be interesting to find out whether these differeing manufacturing techniques result in better sounding components either by chance or directly due to their improved resistanc eto degradation by background radiation.

Dan Banquer · « **Reply #12 on:** 22 Oct 2009, 11:50 am »

Quote from: Browntrout on 22 Oct 2009, 08:25 am

The use of lead is a good idea in my opinion, the only thing that will stop or slow down Gamma radiation is a decent thickness of lead. The effect of Gamma radiation upon the transistor has been studied and has been found to break down the boundries between the material layers (NPN or PNP) rsulting in noticably reduced service life of transistors. Also I believe that very small integrated circuits would be effected, with the continual reduction in size of components (now at around 100um for some) the power of Gamma radiatio to cause spurious results in digital circuits is more probable.
I have wondered myself about whether it would be possible to hear the difference when a vacuum tube is surrounded by say 2.5cm of lead as to my mind the operation of a valve is more susceptable to the degrading effect of this most powerfull form of ambient rediation.
Also there are hardened components that were primarily designed for use in reactors and high radiation environments such as space, these have different constructio to normal transistors/components to prevent radiation from affecting their performance. As to whether they happen to sound better in Hifi I don't know it would certainly be interesting to find out whether these differeing manufacturing techniques result in better sounding components either by chance or directly due to their improved resistanc eto degradation by background radiation.

I would think that if you are really worried about this than get your hands on a Geiger counter and see what it registers. However, if Gamma radiation is a problem I would like to suggest you contact the Department of Homeland Security immediatly.
Regards,
Dan Banquer

JakeJ · « **Reply #13 on:** 22 Oct 2009, 01:05 pm »

Thanks for the humorous commonsense answers from Bill, Dan, & Pat!

I'll throw in with Bill that too much damping can be a bad thing and with JimJ on cabling being a source of noise as they can make great antennas in the right conditions.

Also if your curiosity is still piqued about what metal to use for a Faraday Cage, then I can tell you my research indicates copper is the most widely used and it is what I plan to use to isolate my power supply area inside the chassis of the HagTech Cornet2 phonostage I am designing. FWIW.

Best,
JakeJ

Dan Banquer · « **Reply #14 on:** 22 Oct 2009, 01:23 pm »

Quote from: JakeJ on 22 Oct 2009, 01:05 pm

Thanks for the humorous commonsense answers from Bill, Dan, & Pat!

I'll throw in with Bill that too much damping can be a bad thing and with JimJ on cabling being a source of noise as they can make great antennas in the right conditions.

Also if your curiosity is still piqued about what metal to use for a Faraday Cage, then I can tell you my research indicates copper is the most widely used and it is what I plan to use to isolate my power supply area inside the chassis of the HagTech Cornet2 phonostage I am designing. FWIW.

Best,
JakeJ

You are entirely welcome.
Regards;
Dan Banquer

TheChairGuy · « **Reply #15 on:** 22 Oct 2009, 01:44 pm »

We had a short convo on shielding in The Lab about 18 months...http://www.audiocircle.com/index.php?topic=54415.0

Unless otherwise not available anymore, I bought my TI Shield from Michael Percy Audio.

Regards, John

Speedskater · « **Reply #16 on:** 22 Oct 2009, 02:02 pm »

I think that we have some confusion here with acronyms:
EMI = Electro Magnetic Interference (this is mostly power line related)
EMC =Electro Magnetic Compatibility (a combination of EMC and RFI)
RFI = Radio Frequency Interference

From my Electronics Dictionary:
Mumetal
A metallic alloy with a high permeability and a low hysteresis loss. It is excellent for magnetic shielding.

Dan Banquer · « **Reply #17 on:** 22 Oct 2009, 02:10 pm »

Quote from: Speedskater on 22 Oct 2009, 02:02 pm

I think that we have some confusion here with acronyms:
EMI = Electro Magnetic Interference (this is mostly power line related)
EMC =Electro Magnetic Compatibility (a combination of EMC and RFI)
RFI = Radio Frequency Interference

From my Electronics Dictionary:
Mumetal
A metallic alloy with a high permeability and a low hysteresis loss. It is excellent for magnetic shielding.

For a more specific definition; RFI is a known source of radiation, such as TV or radio station, and EMI is an unknown source of radiation such as an arc welder or lightening.
Hope this helps;
Regards;
Dan Banquer

Browntrout · « **Reply #18 on:** 22 Oct 2009, 11:06 pm »

Quote from: Dan Banquer on 22 Oct 2009, 11:50 am

Quote from: Browntrout on 22 Oct 2009, 08:25 am
The use of lead is a good idea in my opinion, the only thing that will stop or slow down Gamma radiation is a decent thickness of lead. The effect of Gamma radiation upon the transistor has been studied and has been found to break down the boundries between the material layers (NPN or PNP) rsulting in noticably reduced service life of transistors. Also I believe that very small integrated circuits would be effected, with the continual reduction in size of components (now at around 100um for some) the power of Gamma radiatio to cause spurious results in digital circuits is more probable.
I have wondered myself about whether it would be possible to hear the difference when a vacuum tube is surrounded by say 2.5cm of lead as to my mind the operation of a valve is more susceptable to the degrading effect of this most powerfull form of ambient rediation.
Also there are hardened components that were primarily designed for use in reactors and high radiation environments such as space, these have different constructio to normal transistors/components to prevent radiation from affecting their performance. As to whether they happen to sound better in Hifi I don't know it would certainly be interesting to find out whether these differeing manufacturing techniques result in better sounding components either by chance or directly due to their improved resistanc eto degradation by background radiation.
I would think that if you are really worried about this than get your hands on a Geiger counter and see what it registers. However, if Gamma radiation is a problem I would like to suggest you contact the Department of Homeland Security immediatly.
Regards,
Dan Banquer

The only reason for suggesting lead as shielding is to protect against Gamma radiation, hence my post. Perhaps you understand now?
Also RFI is not, by definition, from a known source it is merely EMI that resides within the frequency range denoted as Radio Frequency.
Further EMI is not, by definition, from an unknown source and can of course exist in the Radio Frequency range without originating from a broadcast device.

Bob in St. Louis · « **Reply #19 on:** 23 Oct 2009, 01:04 am »

Take a portable AM radio, placed 'off station' and hover it around your equipment (all of which is turned on of course). You'll hear the interference you're wanting to shield against in the speaker of your AM radio.

I've not tried it, but it was suggested to me from a real smart guy who I respect.

There you go. Have fun.

Bob