$400 1.3GHz vector network analyzer, and a couple of tiny oscilloscopes

My buddy Phil Stittner came to the last analog breakfast with a network analyzer he made from a kit. The kit is based on this nice article by Prof. Dr. Thomas C. Baier, DG8SAQ (pdf), the designer of the circuit. The only problem Phil had was that the oscillator in the analyzer needed very specific transistors in order to work.  Phil tried substituting some he had handy and it would not oscillate. Since there is an RF signal path in this kit they warn people they need to be experienced, which to me means any production tech could whip one out, but if you are a PhD, you better buy the thing pre-assembled. “Doctor, put the soldering iron down and step away from the bench!”

Phil Sittner, the NAPA cowboy, hooks up his kit network analyzer at a recent eFlea analog breakfast.

Here is a screen-shot of the included software (click to enlarge).

Phil, being a pretty thorough chap, didn’t just build the analyzer and hope that it was working. He built two RF filters to check out the analyzer.

Here is the second filter Phil whipped up.

Here is a front-panel shot. Phil’s setup has both the analyzer that interfaces with a parallel port and another board that picks up the parallel port and communicates as well as powers the analyzer over the USB.

And speaking of eFlea buddies, Ed Fong, IC designer, ham radio enthusiast and part-time Berkeley instructor told me about two handheld oscilloscopes. $49 and $89 will get you a lot, especially in view of the fact they have LCD screens.

An ATmega64 based 5 msps 8 bit oscilloscope that you can also get as a kit

And an ARM Cortex-M3 based 1 msps, 12 bits oscilloscope.

Francis Lau, my crack protégé and all around wonder-engineer commented on the Atmel systems:

What I want to know is how the ATmega can do 5msps. It can run up to 1msps at 8 bits? Perhaps they are just running the ADC unit beyond it’s specs. I don’t see any external ADCs… so it’ll be interesting to know the ENOB suffers from this, perhaps you are really getting 6.5 or 7 bits resolution. I would just short the probe to ground and see if the input moves.

If anybody has any experience with any of these units let us know. Me, I am sticking with my lunch-box Tektronix 100MHz scope, my LeCroy 9360 600MHz 5gsp/ch digital, my fabulous Tek 11801B 50GHz sampling scope, and finally, my trusty Tek 2465B 400Mhz analog scope, to put on top of the others so you can find the signal with “beam find” and then prod and poke and program the digital scopes until they show something.