Checkout for used HP 33120A & E3610A - Page 1
Forum section: electronics / testgear

author: cyclin_al
author_rank: Frequent Contributor
timestamp: January 10, 2020, 04:47:05 am
content: I just acquired these 2 devices from a government surplus auction:HP 33120A Function/Arbitrary Waveform GeneratorHP E3610A DC Power SupplyThe bidding made these reasonably priced for setting up a home lab. They are definitely older models.The first step was to go download the manuals and anything else available from Keysight.They were described as functional when they were taken out of service. However, I do not know how long they have been sitting on the shelf, or if they really were functional. That brings me to my question. Based on experience with these units, are there any checks, verifications or inspection I should do before powering them on? After that, are there any recommended functional checks that should be performed once they get powered on?I am looking forward to using these; it has been a long time since I had access to gear and electronics is a change from my usual engineering discipline.Thanks!

author: NoisyBoy
author_rank: Frequent Contributor
timestamp: January 10, 2020, 06:05:58 am
content: Download the owner’s and service manual, all the verification tests are there.

author: cyclin_al
author_rank: Frequent Contributor
timestamp: March 24, 2020, 05:23:09 am
content: Being stuck at home gave me the chance to finally look at these items.I started off with the E3610A power supply. The manual is helpful in that it has a table of Test Equipment Required to check out the unit.The first gotcha is that the table fails to mention the variable autotransformer. I definitely do not have one of those. I am inclined to skip the Source Effect(Line Regulation) check unless there is a reasonable way to get hold of a variable autotransformer?Second gotcha was the Electronic Load. Somehow I assumed at first glance that a car battery load tester would do the job; Not quite. Are there any ideas for a DIY solution or something reasonably similar?Third Gotchas were the resisters. I assumed this would be a simple thing to order from Digikey, but again ran into some challenges.I think I figured out the 2.6 ohm 50 W resistor.Five resistors in parallel at 13 ohms 10 W 5% seems to do the trick:https://www.digikey.ca/product-detail/en/SQP10AJB-13R/13W-10-ND/18738The challenge is getting 0.1 ohm 0.1% 10 W.There are a few options of getting equivalent resistance and power rating but only to 1% tolerance. Even that is not inexpensive.For example five parallel 0.5 ohm 1% 3W resisters is about the closest I could find:https://www.digikey.ca/product-detail/en/vishay-bc-components/PAC300005007FAC000/PPC3D-50CT-ND/596380Any thoughts on how to get to 0.1% or what I should consider in deciding if 1% is good enough?I think I have the 1 ohm 1% 10 W covered as well.1 Ohm, 1% 15W should do nicely with extra power rating:https://www.digikey.ca/product-detail/en/UB15-1RF1/696-1718-ND/5965574

author: JohnPi
author_rank: Regular Contributor
timestamp: March 25, 2020, 03:42:42 am
content: if you are just trying to calibrate it, you don't need precision resistors -- just use the A range on your DVM directly across the supply (be careful not to blow the DVM's fuse -- set VOUT to 0, connect the ammeter, and turn the VOUT knob up).HP expects calibration to be done with a precision R and a voltmeter, but you don't really need that.