Used Agilent E3641A - questions

[vutt]

After being so impressed with HP 34401A DMM I decided to acquire second bench PSU from same HP lineage. With wider voltage range and perhaps more PRO hw than my current OWON clone (also seen on attached pic).

Potential issue - while it works across all ranges and passes trough "hold [Display Limit] button while powering unit up" self test routine I'm concerned about 6 mV voltage while output is off. As seen on attached pic.
Another somewhat related behavior. When I'm doing same hold button power up self test routine it puts out 1V and that stays after self test is done. However 1V goes away after I turn output On-Off and it settles on 6mV. Hm...

Also note to myself - Think twice before buying used PSU-s again. I had to deal with a lot of smelly dust bunnies grown in heavy smokers lab In Japan. Also fan is rattling a little annoyingly. I wonder if Noctua is making HP compatible replacement fans...
 

[free_electron]

really ? 6 millivolts ? that's leakage !

[vutt]

...well my cheap Owon PSU shows only 290 nV with output off...

[strawberry]

If it doesnt drift then should be fine.
they tell something about 4wire and 5mV offset?? 10mV resolution

my 34401a was drifting ohms range before repaired

[vutt]

@strawberry No drifting. So I should be fine. Thanks for replay.

I have another observation/question not worth separate thread. Decided to observe V transients with scope. There is little ~5V voltage drop when I turn E3641A on (yellow trace) compared to switch on without load( grey reference trace). See attachment

I could not replicate this behavior with my OWON PSU so it cant be my DC load fault.
Well PSU is 20+ years old. Could it be that something is starting to fail?
User error - tested it with DC load CC mode...

Otherwise I'm happy with performance. No voltage movements when switching load on/off. OWON has -20mV drift/drop. Also it turns on twice as fast than OWON.

[strawberry]

dont know maybe, OVP trigering
if unregulated voltage drop as well, dry capacitor

[vutt]

I edited my post.
Well this was "user" error LOL. I tested it CC mode, of course DC Load will try to regulate everything else in order to keep current constant. 
I tested it in CV mode - no dips
 
E3641A is actually working as intended.