J-4014, early to mid 60s, in its GRD experimental days.
The 'Gartenzaunantenna' (garden fence antenna) is part of LORAN (long-range navigation), which was installed when the aircraft went to Sweden with J-4013 for weapons testing.
The small fins on the nose tube are for measuring angle of attack and sideslip.
The aircraft is fitted with a tailfin camera, and is carrying two 400kg bombs. Her nose was given the same dayglo orange paint scheme as J-4013.
© Schweizer Flugwaffe, from ein jäger für die schweiz (Borgeaud/Gunti/Lewis)