This Fallout-era AM radio still costs thousands of dollars—why?

My Dad put his Potomac FIM-21 Field Intensity Meter on the bench.

In 1986, this radio cost $1,950—which is nearly $6,000 today! (And this isn't even the most expensive AM radio today—there's a newer version for $15,000!)

It measures the field intensity of AM radio signals in volts, and a calibrated unit like this one can be used for official readings sent to the FCC for broadcast stations in the US.

A few other things we mentioned in this video (some links are affiliate links):

- Potomac FIM-21 Field Intensity Meter: https://pi-usa.com/legacy-products/
- RTL-SDR v4 dongle: https://amzn.to/3KvDbku
- SaferCCTV AN-200 Indoor AM Loop Antenna: https://amzn.to/3KvDdZE
- Gqrx SDR software: https://www.gqrx.dk
- We made a hot dog talk... with RF:    • We made a hot dog talk... with RF  
- Workbench build video:    • Building the ULTIMATE Electronics Wor...  

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Contents:

00:00 - Field Intensity Meter 21
01:13 - Over 900!
02:22 - How to take a measurement
03:14 - Loop antennas, nulls, and SDR
05:56 - External antenna testing
08:16 - What about FM?
09:16 - Why it costs thousands of dollars
10:46 - Field Calibration
13:33 - Is it still useful?
14:46 - The importance of calibration
15:50 - Justifying the cost... with a hot dog?