Author: admin
Tablet cover
A tablet is ideal for portable use, yet it was hard to find a decent case. This is an attempt…
VNA parts list
The parts list here is the digikey parts list . It contains everything needed, except: 1. Transformers – these were…
Electret mic amp
High sensitivity (36dB gain), tested for low harmonic distortion and flat frequency response (1dB down at 40Hz, flat past 30kHz)….
More on transmission lines
PTFE has a more constant (!) dielectric constant over a reasonable frequency range (not that the 4 ohms delta of…
Transmission line calculation tool
Since the steps were too much, this excel file was created. In the spreadsheet, the green values can be entered,…
Twisted pair transmission line
For constructing transmission lines, coax is useful because it is available in 50 and 75 ohms. For transmission line transformers,…
Wire gauges
Wire gauge Excel spreadsheet with AWG and SWG (in inches and mm). American Wire Gauge Standard Wire…
DXF / HPGL to eagle script conversion
There are some Autocad DXF <-> Eagle converters available but they seem to be demo versions, and I didn’t get…
VNA board chopped up
(with a spinning wheel cutting tool, I forget what it is called).
48v 150W power supply (12V step-up)
This allows 48v equipment to be powered from a 12v battery… ideal for power-over-ethernet devices which need 48v. A commercial…