); SAEximRunCond expanded to false Errors-To: [EMAIL PROTECTED] There are a couple of near-mint-looking HP 11729C carrier noise test sets on eBay right now. They are sold by nouturnhere, a great seller in my experience. They have the AM noise detection option (130) and all of the available filters from 5 MHz to 18 GHz.
Basically this is a general-purpose microwave downconverter whose LO uses harmonics of the 640-MHz reference output from an 8662A/8663A to downconvert the signal to be measured to a frequency below 1280 MHz, where it is then mixed down to a baseband IF with the same 8662A's output. An 8662A is not mandatory, but it's convenient because it can provide both LOs at once. The baseband IF is high-pass filtered at 10 Hz to get rid of the DC component, amplified by 40 dB with a 1.6-dB LNA, and fed to a spectrum analyzer for noise measurement. There is also a general-purpose PLL that can be used to maintain phase quadrature. A good description of the whole thing is in this app note: http://www.home.agilent.com/upload/cmc_upload/All/5952-8286E.pdf There are two units left right now. I have no idea of $969 BIN is a good price or not, but they are rare enough, especially in this condition, that I thought it was worth snagging one. If it turns out to be in good shape, I will add the necessary GPIB and user-interface code to PN.EXE to allow it to work with any of the spectrum analyzers currently supported. The system noise floor with one of these is not as good as a Wavecrest box for low-frequency carrier measurement, but it is much better than a spectrum analyzer by itself, and hey, it goes to 18 GHz, right? -- john, KE5FX _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
