You mean only transistors and valves? Not even LM555?IC,ARDUINO not allowed.
There goes 74% of the"answers".Not even LM555?
There goes another 24%.ARDUINO not allowed.
AHA!!! (now that I'm fully awake) -Not even LM555?
Harbor Freight, $4.00. I got mine for 1.99.Make your own bug zapper racket. These things are spectacular BTW, if you live in a buggy area:
https://www.amazon.com/DAEN-Electri...sr=1-2-spons&keywords=bug+zapper+racket&psc=1
Really cheap for an EMI susceptibility tester.Harbor Freight, $4.00. I got mine for 1.99.
https://www.harborfreight.com/catalogsearch/result/index/?dir=asc&order=EAScore,f,EAFeatured+Weight,f,Sale+Rank,f&q=zapper
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