HP 8640B LF ?
 

I just acquired an HP 8640B and now I'd like to get rid of my HP 606A but I
need to go below 500 KHz. I wonder if anyone has had any experience with
the HP 11710A or B that they'd care to comment on. I'd also like to know if
there's any other reasonably priced LF sig gen that's stable and has a
calibrated output that I should consider as $150.00 for an HP 11710 seems
kind of high when you can find HP 8640Bs for around $200.
tnx
hank wd5jfr