Sounds like your goal is to get an idea of the relative impact that a change makes. For example, you have failed by 4dB at the test house and you want to try to mitigate the problem back at the office. You measure the product as it is, make a change to the product, and measure again for a delta (change in emissions). In this case, you would want to see a delta of at least 4dB. For this type of testing, I don't think you need a shielded room or an outside site. In the past, I have set up an antenna in a conference room to make measurements of this nature. I didn't use a ground plane. In fact, I have positioned the antenna as close as 1 meter from the product so the emissions from the product will rise above the ambient. The readings on the spectrum analyzer will not be accurate, but at least you can see the delta between changes. The delta that you observe should be relatively believable regardless of antenna position. This technique is not valid for pre-compliance te! sting however. In this case, you should strive for accurate readings.
Allen Tudor, Compliance Engineer PairGain Technologies tel: (919)875-3382 6531 Meridien Drive fax: (919)876-1817 Raleigh, NC 27616 email: allen_tu...@pairgain.com >>> <pah...@pebio.com> 01/13 4:48 PM >>> Society, Our company is contemplating a 3m lab for preliminary emissions scans. We aren't looking for "submittable" results, but rather, a decent indicator of whether or not modifications to the EUT improve emissions. In your opinions, what is the minimum setup needed to achieve this? Without a proper ground plane and some sort of shielding on the walls, can a spectrum analyzer/antenna setup do any good? How are other company's labs set up? I've heard of people putting an open lab on their roofs. What kind of results do they get? Any opinions, experiences, or ideas are appreciated. Thanks, Brent --------- This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). --------- This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
