When I wanted to build a diplexer, I read that this can be done by using a highpass anda lowpass filter. But what if someone wants to make a multiplexer, or if one wants to use bandpass filters?
My next project is to build a GPS disciplined oscillator. I have bought a NEO6M GPS module (GY-GPS6MV2) which uses an active antenna. However, there are several drawbacks which I want to fix first.
Here I show how I designed a coaxial cavity bandpass filter. The method of Dishal is employed, using the k and q values. This was part of my Master’s Thesis, but here it is explained in more detail.
Recently I needed a N type calibration kit. We don’t have one at work, but since I already have gained some experience with building a SMA calibration kit, I decided to make my own N kit!
I have a good old HP 8753C vector network analyser in my shack, however, I miss a proper SOLT calibration kit. Here is how I built my own calibration kit and made a model for the 8753C.
In the service manual of the HP 8753C, I read something about a cavity oscillator which is used in this instrument. Later, I read some article in the HP Journal, also about cavity oscillators. Time to build my own!