After further digging into my Ref Unlock error message on the HP8591A Spectrum Analyzer I have found the following.
The 600 MHz SAW oscillator on A9 Third Converter assembly seems to oscillate at only 599.744 MHz on its own (without 10 MHz reference connected).
With the 10 MHz reference connected, the frequency only comes up to 599.920 MHz - It does not reach 600 MHz.
The VTO_TUNE signal between the Counterclock assembly and the A9 Third Converter assembly is maxed so it can not tune the 600 MHz SAW oscillator any further.
?
Can the 600 MHz SAW oscillator be tweaked in some way or is the next step to replace the A9 Third Converter assembly?
