Not sure how much they want to spend, but there is a Magnum Dynalab Signal Sleuth on here for sale. They work incredibly well. No relation to the seller. I've owned one of these and they do work really, really well.
https://www.audiogon.com/listings/tuners-magnum-dynalab-md-205-signal-sleuth-2016-05-17-miscellaneou...
https://www.audiogon.com/listings/tuners-magnum-dynalab-md-205-signal-sleuth-2016-05-17-miscellaneou...