Recommendations for a Spectrum Analyser for Work? - Page 1
Forum section: electronics / general

author: David
author_rank: Frequent Contributor
timestamp: January 28, 2013, 07:11:59 pm
content: Hi All,I am in the process of persuading work that we require a Spectrum Analyser for some basic EMC pre-compliance (Conducted emissions + close-field probing). Originally I thought of the Rigol DSA815-TG for some basic work but we are soon introducing some 2.4GHz Zigbee transceivers into a design so it would be nice to look at higher frequency emissions etc. I've had a look at Agilent and it seems they have some fairly good low-end analysers for a decent price (although once you've added all the optional extras that you would require anyway it soon adds up!). Any recommendations? We are only looking around the <£10K mark.Cheers,Dave

author: jeroen74
author_rank: Frequent Contributor
timestamp: January 28, 2013, 08:34:22 pm
content: I guess you need one that has some calibrated absolute level accuracy which is important for EMC. What I've heard cheaper analyser are not too good at this.TheR&S FSLis a low cost spectrum analyser. I used it at a previous job. R&S is a very reputable brand, it's the stuff you find at EMC labs.

author: David
author_rank: Frequent Contributor
timestamp: January 28, 2013, 08:50:20 pm
content: Yes, some form of guaranteed absolute accuracy would be nice. However this will still be a lab set-up so there is some margin of uncertainty in the measurements. I'm currently looking at R&S and Agilent/HP. Am I correct in saying a 3GHz analyser wouldn't be sufficient for 2.4GHz work?

author: MartinX
author_rank: Regular Contributor
timestamp: January 28, 2013, 08:59:31 pm
content: Any analyser that covers the frequencies of interest is a great help, it comes down to how advanced you are planning on getting, are you going to expand your capabilities in the future?Older used analysers can be great value if you get one with quasi peak and average detector, the correct bandwiths, pre amplifier, etc but they often only have GPIB that makes communicating with a pc and saving results and setups a bit difficult. A tracking generator is also good as it enables you to check that LISN and CDN you build yourself are reasonably correct.One option you cannot be without is the built in pre amplifier because the near field probes are not very sensitive, it is also often a hardware option not easy to add later. Absolute accuracy is not that important unless you have a real EMC chamber with absorbers, calibrated antennas and such, the levels you get will always be off, most analysers will be more than adequate anyway.

author: David
author_rank: Frequent Contributor
timestamp: January 28, 2013, 09:19:02 pm
content: Current contenders below. I will update this list as I go so I can keep track...I feel a spreadsheet coming along!N9322C Basic Spectrum Analyzer (BSA), 9 kHz to 7 GHzhttp://www.home.agilent.com/en/pd-2202248-pn-N9322C/basic-spectrum-analyzer-bsa-9-khz-to-7-ghz?nid=-536902453.1039398&cc=GB&lc=eng£9541 (ex VAT) inc Pre-amp, TGR&S®FSC6 model 16http://webstore.rohde-schwarz.com/uk/r-srfsc6-6208.html£8960 (ex VAT) inc Pre-amp, TGDave

author: robrenz
author_rank: Super Contributor
timestamp: January 28, 2013, 11:31:34 pm
content: Check out Shahriar's video review of a higher end Rigol. I think it is a 3GHz model.http://youtu.be/lu2Uaj3ZcoA

author: Psi
author_rank: Super Contributor
timestamp: January 29, 2013, 02:08:54 am
content: Quote from: David on January 28, 2013, 09:19:02 pmhehe, I'd hardly call 7GHz "basic"

author: PA4TIM
author_rank: Super Contributor
timestamp: January 29, 2013, 03:46:14 pm
content: Hameg has a decent 3GHz SA with a separate available EMC option.

author: David
author_rank: Frequent Contributor
timestamp: January 29, 2013, 06:41:41 pm
content: Quote from: Psi on January 29, 2013, 02:08:54 amMy thoughts exactly!

author: David
author_rank: Frequent Contributor
timestamp: January 29, 2013, 07:00:47 pm
content: eBay auction: #Quote from: PA4TIM on January 29, 2013, 03:46:14 pmI've just had a look at this....looks quite promising! Not the best spec in the world but you get a 3GHz SA, Near-field probe set, LISN and EMC software for £4545.http://www.hameg.com/611.0.html?L=0Dave

author: AndyC_772
author_rank: Super Contributor
timestamp: January 29, 2013, 07:30:11 pm
content: My 2p...Unless you have a chamber or open air site, and a way to calibrate your setup, I think you'll be limited to identifying obvious sources of noise and major flaws in your transmitted rf signal rather than being able to tell in advance whether or not a product will pass EMC when you get to the lab. For that reason, I wouldn't worry too much about the analyser itself.For pre-compliance work, last year I bought an HP 8594E which was specifically recommended to me by the EMC lab we use. It was about £3k IIRC, and it came with a quasi-peak detector included - not that there's really much point in that unless you have a calibrated setup to begin with. For conducted emissions testing I also bought a LISN, and to use one of those you'll need an isolation transformer (plus a variac too if you want to test at both 120V and 240V). They'll trip an RCD breaker otherwise.I'd suggest giving something like this a try - and if it turns out not to meet your needs, there's a good s/h market for this type of kit so you needn't lose much. But I reckon it'll be ancillary kit that'll let you down if anything (antennas, amplifiers, somewhere reasonably quiet to do the testing in the first place) rather than the analyser itself.

author: David
author_rank: Frequent Contributor
timestamp: January 29, 2013, 07:38:10 pm
content: Quote from: AndyC_772 on January 29, 2013, 07:30:11 pmHi Andy, thanks for your input! Just to clarify, the primary use of the SA would be for conducted emissions pre-compliance testing. The only other real use I can see at the moment is for taking relative radiated measurements with near-field probes in order to try and identify areas of a design which may be radiating more than others. The 2.4GHz stuff I mentioned was really just to see when the transceiver was operating and for nothing else. One downside I can see with that Hameg analyser is that its frequency range only goes down to 100kHz...however most requirements we have would be 150khZ to 30Mhz.Dave