Power Supply Impedance Measurements Using an AP300 Frequency Response Analyzer

After testing a Keysight E5061B-3L5 and an Omicron Bode100 VNA, I got another LF frequency response analyzer (not a full VNA) on loan, the AP Instruments AP300. This unit has a low frequency limit of 10mHz, way lower than the other instruments. It looks like this:


I use these units to determine the output impedance of linear, low noise power supplies.

Click here for a Power Supply Impedance Measurements Using an AP300 Frequency Response Analyzer …

Phase Noise Measurements of Homemade and Commercial Oscillators and Signal Sources

Having an FSUP Phase Noise Analyzer on loan for an oscillator project (thanks N1UL !) I had the chance to check the phase noise of some commercial and homebrew oscillators and signal sources.


PhaseNoise10MHzRubidiumStandardLPRO1Hz1MHzFSUPThis a an EFRATOM LPRO101 Rubidium Standard. I also measured a commercial MillRen OCXO, a GPS standard, a Keysight N5171B RF signal generator and a RIGOL DG1062Z.

Click here to see some Phase Noise Measurements of Commercial and Homemade Oscillators …

Silly Circuits -Unusual Behaviour of Crystal Oscillators

Normally, crystal oscillators are standard components, used thousands of times without too much engineering attention necessary. If it comes to high quality crystals, a lot of unexpected effects can occur, like generating several nonharmonic frequencies at the same time and even chaotic behaviour.

here in the time domain:

Click here to see some Unusual Behaviour of Crystal Oscillators …

Using the Keysight AutoProbe Interface in Your Own Projects

As an owner of some Keysight equipment I wanted to use some probes intended for the Oscilloscope AutoProbe connector on other test equipment like VNAs or spectrum analyzers. I asked how to do this at the Keysight forums, but nobody had an answer for me there except that it does not work.

OK, lets homebrew something and see how far we get.



To make a long story short, it worked after a while of research and testing.

Click here to See Using the Keysight AutoProbe Interface in Your Own Projects …