connector 1
connector 2

The BNC DC to 4 GHz; RoHS 2(EU) The BNC can be used on cables both flex and semi rigid, characteristic impedance of 50Ω. Manufacturer is Amphenol (NYSE:APH)

1/4 inch Super Flex Helix Cable 50Ω, Foam Dielectric Commscope Part Number (FSJ1P-50A-4), NASDAQ:COMM

DC to 11 GHz, 50Ω, Brass Body per QQ-B-626, Nickel plated, Gold Plated center contact, interface to MIL-C-39012 Mfg Amphenol Connex