View Single Post
Old 20th Jun 2016, 9:16 am   #4
Nymrod121
Octode
 
Nymrod121's Avatar
 
Join Date: Apr 2012
Location: Worcestershire, UK.
Posts: 1,869
Default Re: HP8640B questions

Hello John

I've done a bit of work on this type of generator and my records refer to the following:

4-40 UNC x 0.125" small cup point (hex key = 0.05" across flats)
6-32 UNC x 0.125" small cup point
2-56 UNC x 0.094" small cup point (hex key = 0.035" across flats)

http://www.modelfixings.co.uk/steel_grub_screws.htm#UNC grubs

They do a range of suitable hex tools as well.

I assume from the early serial number that your instrument has the earlier system of 'range vs deviation interlock' - otherwise known as 'A9' assembly - that uses wafer switches rather than the later PCB-tracked switches? - if so, I've done a lot of work regarding replacement of the Delrin hardware ...

Best wishes

Guy
__________________
"Halt! - who goes there?"
'Baa-aa-aah ..." ('The Dish': 2000)

Last edited by Nymrod121; 20th Jun 2016 at 9:18 am. Reason: A9 assembly ref added
Nymrod121 is offline