What is this Port? It is not a 16mm type cable. It belongs to the "Grundig EN3" an old voice recorder from the 50s/60s. I want to plug headphones in, Im asking
1967 GRUNDIG EN3 :: Audio Media Evolution
1964 Grundig EN3 Dictaphone, Reel to Reel Cartridge : r/vintage_electronics
Diktafon Grundig EN3 Dalekohledy, Digitální fotoaparáty, Foto Bazar - FOTO OPTIKA JAN PAZDERA
Grundig EN3 Electronic Notebook ORIGINAL Service Manual | eBay