Wow, these are very high levels. There is certainly a problem. I would first suspect the cabling into the chamber- is is bonded at a bulkhead? Also, if the receiver/spectrum analyzer is in the chamber you will see lots of stuff. Dave Cuthbert Micron Technology
From: [email protected] [mailto:[email protected]] On Behalf Of [email protected] Sent: Saturday, March 13, 2004 8:15 PM To: [email protected] Cc: Ken Javor; [email protected]; [email protected]; T.Sato Subject: Noise level inside an fully anechoic chamber Dear Experts, I am conducting pre-scans in a 3-meter fully anechoic chamber. It is noticed that even when no equipment is present inside the chamber the field strength is about 20 to 25 db micro volts per meter in the frequency range 30 to 350 MHz, about 27 to 32 db micro volts per meter in the frequency range 350 to 600 MHz and about 33 to 39 db micro volts per meter in the frequency range 600 to 1000 MHz. What is the level of ambient noise permissible in fully anechoic chambers? Which section of FCC deals with measurement site qualifications? Sincerely K.Balasubramanian Sr.Engineer, Hardware.
