I won an military auction lot recently which included a HP 83731A signal generator as I have no use for it or even much idea of what to use it for (other than from Shahriar's awesome videos) I thought it might as well find a new home where it could see actual use.
The unit has the following options installed
83731A - 1E1 ADD 90DB OUTPUT STEP ATTENUATOR
83731A - 1E5 ADD HIGH-STABILITY TIMEBASE
83731A - 1E8 ADDS 1HZ FREQUENCY RESOLUTION
And was last calibrated by Trescal on the 22-09-2014 and passes the self test.
A quick browse on google gives the following links
Datasheet:
http://www.axiomtest.com/documents/models/Keysight%2083731A%20Data%20Sheet.pdfManual:
https://www.topdogtest.com/inventorypdf/83731AOpGuide_usr,ops.pdfService manual:
http://exodus.poly.edu/~kurt/manuals/manuals/HP%20Agilent/HP%2083731A,%2031B,%2032A,%2032B%20Service%20Guide.pdf I honestly have no idea of the value of this instrument, however browsing on ebay have the cheapest buy it now for 3700 €, that unit does however not have the high resolution option but instead has a modulation option so not fully comparable.
Just to start somewhere let us say 3000 €, but please if you have any intelligent input on this feel free to sent me a pm or leave a post, especially if you are not looking to buy yourself