[tbw2]

Assembling A Low Cost EMI Troubleshooting Kit – Part 1 (Radiated Emissions)
https://interferencetechnology.com/assembling-low-cost-emi-troubleshooting-kit-part-1-radiated-emissions/

[delphifalcon]

Check out the portable tinySA spectrum analyzer for $49.95.

This marvel is about the size of a deck of cards and covers 100 kHz to 960 MHz.

It’s my first go-to instrument for tracking down EMI issues.

[Theophilus]

u need a 100,000 cu ft rf anechoic chamber

[EasySt]

What do you think about one of these?

RF Explorer Digital Handheld Spectrum Analyzer 6G Combo Plus - Slim
50KHz to 6.1GHz handheld (PC connectable, w/free software. $395)

https://www.amazon.com/dp/B089QBXX6C/ref=cm_sw_em_r_mt_dp_QY1SNPGACC0WX1W0MCY3

It seems it would cover the spectrum affordably...

~Easy