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Old 8th June 2009, 05:49 PM   #19461
KSTR is offline KSTR  Germany
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Does anybody still have/use AM (SW/MW/LW) radio?

I use my pocket world-reciever to quickly find major RF emitters... it's amzing how much dirt is in the the air and on cables today, compared to like 10 or 20yrs ago... also emitted from displays of CDP's etc. People have reported that their systems sound better when all displays are turned off, for good reasons...
 
Old 8th June 2009, 06:02 PM   #19462
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KTSR, did you happen to notice that the BLOWTORCH does NOT have any displays, not EVEN an LED? That is on purpose. We have known about RFI generation for decades in solid state displays.
 
Old 8th June 2009, 10:16 PM   #19463
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Mr.Curl,

How bad a source of RF radiation is a led?

Regards,

Jam
 
Old 8th June 2009, 10:18 PM   #19464
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The problem with LED is the opening in the case
 
Old 8th June 2009, 10:30 PM   #19465
jam is offline jam  United States
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Good point. I never thought of that.......

JAM
 
Old 8th June 2009, 10:43 PM   #19466
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We could even determine the cutoff freq of that 3mm hole with the formula in the ETS-Lundgen datasheet I linked to a few days ago...
 
Old 8th June 2009, 11:16 PM   #19467
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Quote:
Originally posted by Joshua_G
The problem with LED is the opening in the case
What opening in the case? Clear plastic and black plastic have about the same RF properties.

Jam - I did a double take today one of my guys put a big plastic copy of your avatar on top of his desk.
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Old 8th June 2009, 11:21 PM   #19468
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Quote:
Originally posted by jam
Good point. I never thought of that.......
Yeah, 20 GHz is a very dangerous frequency.

Sorry, Couldn't resist.
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Old 8th June 2009, 11:46 PM   #19469
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I can't say.
 
Old 9th June 2009, 12:22 AM   #19470
KSTR is offline KSTR  Germany
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Scott, while I have your attention...

... you once mentioned spark gap calibration etc of microphone capsules (Earthworks does this, IIRC). Are there any accessible sources that one could exploit? I think I understand the basic principle (the "rectangular" nature of the pulse -- not a dirac) but would like to learn more about it.

- Klaus (and, sorry John, polluting "your" thread )
 

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