Any idea what these tube sockets are for?

[EastPoint]

Anyone ever seen these before? They're modified octal sockets, and have one banana jack built-in, as well as only 5 terminals instead of the usual 8.

 

[soundmotor]

There's an odd timer or delay tube with one long pin. I suspect that's the socket for it.

 

[Pio1980]

Octal Klystron tube, my best guess.
http://www.decadecounter.com/vta/articleview.php?item=659

 

[gadget73]

I was thinking umbilical cord socket.

 

[soundmotor]

Octal Klystron tube, my best guess.
http://www.decadecounter.com/vta/articleview.php?item=659

That's it.

 

[EastPoint]

I love you guys. Thank you.

 

[nj pheonix]

Radar tube?

 

[Pio1980]

Radar tube?

Yes, downconversion local oscillator.
http://electronicparts-outlet.com/en/klystron/835-rk2k25-klystron-cavity-reflex-raytheon.html