LCD Upgrade for the HP 141T Spectrum Analyzer [Part 1]

In this video I demonstrate my progress so far on building an intelligent LCD display upgrade for the HP 141T. I use an STM32F746G discovery board with a 4" touchscreen, and demonstrate a few neat features:

  • Real-time spectrum display with graticules etc, that works on the slowest up to the fastest timebase
  • A waterfall display mode
  • A normalization function that makes insertion loss measurements much easier.

I also take a brief look at the codebase (which is very hacky at the moment!)

GITHUB REPO: https://github.com/schnommus/stm32_hp141_lcd

Rapid Prototyping RF Filters with Tape & QUCS

Was lucky enough to get this featured on Hackaday! See: Rapidly Prototyping RF Filters

A guide to simulating microstrip filters in QUCS and prototyping them with copper tape on blank FR4 sheets. These super-cheap materials are good up to a couple gigahertz, as you'll see in the video.

Following a quick real-time demonstration, I simulate and build 2 microstrip filters, a 1GHz stepped-impedance LPF, and a 10GHz end-coupled BPF.

(Checkout the youtube description section for active timecode links)

2:05 - 1/4 wavelength stub build & tests 3:46 - Radial stub build & tests 4:18 - Stepped impedance microstrip LPF design 6:42 - Stepped impedance microstrip LPF build & tests 9:10 - Trimming the stepped impedance LPF 10:26 - Brief tutorial on synthesizing filters in QUCS 14:51 - Synthesizing a 10GHz end-coupled microstrip BPF 18:33 - 10GHz end-coupled BPF build & tests