[Test-Equipment] Help needed: ITC Instruments SA1800A Spectrum Analyzer

[Heinz Breuer DH2FA]

Hello,
about 15 years ago ITC Instruments in San Diego promoted their spectrum 
analyzer in ham radio magazines CQ and QST.
I bought a SA 1800A spectrum analyzer, tested it and disapointed put it 
back in its shipping box. I got it out again yesterday only to find that 
the "tracking generator" does not work. The circuit is no tracking 
generator but a noise source. Unfortunately the schematics in the thin 
manual are either unreadable or not present at all.
I wonder if somebody here could help me with better schematics or any 
idea for usable noise source. If there are any others users of this 
spectrum analyzer I would appreciate to hear from you.
Best regards
Heinz DH2FA, KM5VT