In this project, we open up a cavity duplexer from a Sprint / Nextel iDEN cellular repeater.  We see the interior where all the black magic happens, attempt a repair and reassemble it against all odds of success.

One of the important components of my GPS-disciplined oscillator project is the signal distribution board.  The oscillator sends its pure signal through an isolation / buffer amplifier, then through an RF splitter.  The splitter sends one copy of the signal to the digital control circuits and another copy to the distribution board.

This project was a quest to build a convenient connector panel for my bench power supply.

This is the 3rd in a series of continually improving designs for a high quality sampling head for making RF signal measurements.  The 1st and 2nd versions (and what they do) are described in this article.  This version has the best frequency range and power handling capability.


This started as a quest to build an atomic frequency standard based on a rubidium oscillator.  After realizing that I could get much better short-term stability and long-term accuracy by building around an ovenized crystal oscillator that's disciplined to a GPS time reference, the project was retargeted.