UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post

XTC · 3rd Sep 2009, 11:29 am

Al,

There's a yahoo! HP group where you are likely to get answers to specific problems.

http://tech.groups.yahoo.com/group/h...ent_equipment/

There's also this site

http://www.shelbrook.com/~ve7ca/TstH86.htm

which describes 8640B repairs.

Some of the links are good such as

http://www.johanforrer.net/HP8640B/index.html

There's a warning I came across that there were many mods to the 8640B during its production life and you have to be sure your copy of the manual covers your version.

There's also a warning about not storing them on their backs. Grease migrates into the cavity and causes problems.

I can't help with specifics. I've had mechanical problems with my 8640A but no electrical problems until recently, when it's started to do strange things when it gets warm.

A while back I saw a cavity oscillator, factory sealed, on ebay for about £20 I recall, so it's worth looking out there.

Pete.

3rd Sep 2009, 11:29 am	#9
XTC Retired Dormant Member Join Date: Oct 2004 Location: Bristol, UK. Posts: 837	Re: HP 8640B maintenance. Al, There's a yahoo! HP group where you are likely to get answers to specific problems. http://tech.groups.yahoo.com/group/h...ent_equipment/ There's also this site http://www.shelbrook.com/~ve7ca/TstH86.htm which describes 8640B repairs. Some of the links are good such as http://www.johanforrer.net/HP8640B/index.html There's a warning I came across that there were many mods to the 8640B during its production life and you have to be sure your copy of the manual covers your version. There's also a warning about not storing them on their backs. Grease migrates into the cavity and causes problems. I can't help with specifics. I've had mechanical problems with my 8640A but no electrical problems until recently, when it's started to do strange things when it gets warm. A while back I saw a cavity oscillator, factory sealed, on ebay for about £20 I recall, so it's worth looking out there. Pete.