As expected the filter works nicely. It's old, analog technology. I like that.
The world however has become digital, to some degree. Found GS3PYE/P on 80 meters this evening, and a few minutes later looked up the call sign on Google, and found that I was in the online logbook.
And it turns out to be a returning expedition to islands in Scotland, this year to the Isle of Mull, EU-008. Many hams involved. Lots of technology involved. Very nice!