Hello all, I would like to pay a spectrum analyzer and need some advises. I work in designing circuits in frequencies from 0-100Mhz. I found on the web some models but I have no idea about their quality. All following models have the same look and specifications with tracking generator: BK2639 $1870 Link: http://www.tequipment.net/BK2630.html Hameg HM5510 2225$ no tracking generator http://www.testequipmentdepot.com/hameg/spectrumanalyzers/hm5010and5011.htm Instek GSP-810 $2140 http://www.tequipment.net/InstekGSP810.html China made SM5011 $570 http://mch.en.alibaba.com/product/200992481-200171175/SM5011_Spectrum_analyzer.html these models has the look ans specs, but the prices are very deferent, the chaines (SM5011) is very cheap. Did any body owned this model? is it reliable? accurate? any advises please. it seems to me they are the same device with defernt names. I appreciate any help very much.