One sector of the amateur radio hobby is known as "fox hunting". No furry animals are involved in this, er, pursuit - it's about finding hidden radio transmitters. Often now known under rather more PC terms such as ARDF or Radio Orienteering.
Although much of it takes place on the 2 metre VHF band, 80 metres is also used.
There are various kits available for small handheld receivers and the 80m types are very useful for tracking down interference, even though they only cover a small frequency range.
A typical kit is this one, which I have used successfully for tracing sources of noise from computers, video screens, SMPSU's etc:
http://www.nationalradiocentre.co.uk/ardf/80mrx.html
I don't know how old that page is, so if you consider ordering one, check with the supplier first...
Another version here - online plans, but in the Dutch language:
https://www.qsl.net/pa3fdc/tech/hrx80/
There are plenty of others available but, as always, be aware that the quality of cheap Chinese stuff sold online can be very hit or miss.
I know this is not exactly what you are looking for, but some may find it helpful.