[Electronic M]

Originally Posted by bandersen

Or use these amphenol to BNC adapters. Hmm. Looks like you would need to cut down the center pin?
https://www.ebay.com/itm/125955958203

Those look like PL-259 which isn't compatible with the old microphone connectors used on the B&K 415.

Those mic connectors aren't hard to change to BNC. Just a hot lead solder joint and a nut for ground and mechanical mounting. I had some spare BNC connectos off of a junked SS monitor and they bolted right in.