Vector Network Analyzers have come down in price to the $100 range, which is amazing in and of itself, so the home experimenter, likely a Ham radio operator, has a lot more capability to precisely measure things that were pure guesswork in the past.
Of course, the anechoic chamber is a nice thing to have. I once got to see the Anechoic chamber at Northrup Grumman near Chicago during a open house... a theater size room they used for various measurements. I'll never forget it.
This is a nice collection of information. The other place to get this type of data in the past was the Amateur Radio Handbook from the ARRL.
You can always make impedance measurements with a slotted line, 6-port reflectometer, or vector voltmeter if you don't have access to a VNA. My undergrad microwave professor had us learn on the slotted line before letting us touch the VNA.
Of course, the anechoic chamber is a nice thing to have. I once got to see the Anechoic chamber at Northrup Grumman near Chicago during a open house... a theater size room they used for various measurements. I'll never forget it.
This is a nice collection of information. The other place to get this type of data in the past was the Amateur Radio Handbook from the ARRL.