Microwave measurement equipment is very expensive, especially for amateur radio use. On flea markets, we can find much old equipment, some older than 40 years. With old equipment is always a problem with repair and maintenance. VNAs offer is not so often, especially for good (reasonable) price, with Spectrum Analyzer is a bit better. So we can try bought something on eBay or flea markets, or make a measure on ham radio (microwave) meetings, or build some by home.
Henrik Forstén has built a one excellent Vector Network Analyzer, from 30 Mhz to 6 Ghz. On Henrik’s web pages you can find last, improved version. On GitHub are available all the design files
All photos: www.http://hforsten.com
