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For Tom - The Tempest Box and EMI shieling
Posted by Idreamin3D
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For Tom - The Tempest Box and EMI shieling September 12, 2010 03:41AM |
Registered: 14 years ago Posts: 120 |
Hi Tom,
I have a question with regard to EMI and T2/F75. I have read about your tempest box experiment and that you were able to run the F75 at max without any falsing. Now I know that First Texas sprays the inside of the control box with a coating of graphite to shield against EMI, but graphite is not the best EMI shield. I was thinking of designing and making my own EMI shield that could be placed over the control box without voiding the warranty, like a control box cover but with 1mm lead in it. I can also get EMI resistant glass that I could cover the LCD screen with.
Now for my question; is the control box the only place where EMI is having a negative effect on the detector? For some reason I feel like the coil is the main antenna for EMI and obviously I cant shield it. Well, I guess I could if I covered it with a magic coating of something that only allowed the detector frequency to go through.
So do you think I would be able to gain some increase in performance if I was able to block 90% of EMI hitting just the control box? Would 1mm lead shielding be able to block this much EMI? I am really hopeful for this to work, but as a realist I think that if this simple solution would solve the EMI problem, Dave Jonson would have done it ages ago buy covering the inside of the control box with a thin layer of lead and not graphite.
Eagerly awaiting your response,
Thanks,
Yev
I have a question with regard to EMI and T2/F75. I have read about your tempest box experiment and that you were able to run the F75 at max without any falsing. Now I know that First Texas sprays the inside of the control box with a coating of graphite to shield against EMI, but graphite is not the best EMI shield. I was thinking of designing and making my own EMI shield that could be placed over the control box without voiding the warranty, like a control box cover but with 1mm lead in it. I can also get EMI resistant glass that I could cover the LCD screen with.
Now for my question; is the control box the only place where EMI is having a negative effect on the detector? For some reason I feel like the coil is the main antenna for EMI and obviously I cant shield it. Well, I guess I could if I covered it with a magic coating of something that only allowed the detector frequency to go through.
So do you think I would be able to gain some increase in performance if I was able to block 90% of EMI hitting just the control box? Would 1mm lead shielding be able to block this much EMI? I am really hopeful for this to work, but as a realist I think that if this simple solution would solve the EMI problem, Dave Jonson would have done it ages ago buy covering the inside of the control box with a thin layer of lead and not graphite.
Eagerly awaiting your response,
Thanks,
Yev
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Re: For Tom - The Tempest Box and EMI shieling September 12, 2010 07:38AM |
Registered: 14 years ago Posts: 120 |
Well, I just found the answer on this, looks like I am not the first to ask.
NASA-Tom [ PM ]
Re: Question maybe Tom could help with EMI
May 04, 2010 04:30PM Registered: 4 years ago
Posts: 2,525
Most EMI enters the unit through the coil. Picked up from surrounding atmosphere. You obviously do not want to put any shield tape on the coil. Shielding the control box/head.......will produce minimal effect.
As far as attaching a ferrite choke core (magnet) around the coil cable... would suit no purpose...........as the cable is already shielded; rendering any additional external apparatus useless. . . . . . aside from the fact that EMI has already entered into the coil.
NASA-Tom [ PM ]
Re: Question maybe Tom could help with EMI
May 04, 2010 04:30PM Registered: 4 years ago
Posts: 2,525
Most EMI enters the unit through the coil. Picked up from surrounding atmosphere. You obviously do not want to put any shield tape on the coil. Shielding the control box/head.......will produce minimal effect.
As far as attaching a ferrite choke core (magnet) around the coil cable... would suit no purpose...........as the cable is already shielded; rendering any additional external apparatus useless. . . . . . aside from the fact that EMI has already entered into the coil.