I need to test that my project will not interfere with radios in the 27 - 72 MHz band.

I can't afford a spectrum analyser. Nor can I afford to buy all tx/rx pairs in between 27 and 72 MHz (27, 35, 47, 72...) My budget is a maximum of £100.

I was thinking of modifying a radio to have a much larger tuning range, but it would need to be sensitive to very low EMI emissions. I've found AM radios are slightly sensitive to noise but probably not enough.

Does anyone have any suggestions?