HP 6114A Precision Power Supply (56K warning)

[schopi68]

Hmmm... i did not see many used hp boxes with replaced posts. 

Well - i am using used gear from hp. Because i know, it is not made by compaq-hp and has a higher quality than many of the brand-new today's devices, especially when comparing the price.

On old HP-Boxes (and the ones from other manufacturers) i see dents and cracks on the knobs very often. Dents are the result of bumping something onto the device. Well, it's quite normal that something that sticks out of the device is more suspectible to be broken.

There are some - in detail visible - advantages of the hp-posts compared to cheap ones (this does not mean that there are no other good ones on the market, but these are not cheap too). Longer lasting materials, terminal plates even on the screw-handle and so on. On old devices with cheap posts you will get contact problems very often.

[linux-works]

buy some new pomona brand posts, then.  they will be high quality, affordable (sort of) and if you buy real parts they will last.

[schopi68]

Nope, Material quality seems to be finde on ne Pomona posts - but i can see that have the same grip-area than all the others. One of the differences to the hp-ones. The typical hp parts have a slightly larger diameter and grooves that give more grip. This makes a feelable difference in screwing. And: a device with this posts still looks like a self-made repair.

[eas]

I've started to work on my own new old HP 6114a precision power supply.

So far I've just done some cleanup and body work, and check for any damaged components. I plan to put it back together and do some power tests this weekend and post an update then.

[bitseeker]

Hey, eas. I recognize that 6114a. It was on my watch list. You're doing great work on it.

[wade salt]

Hi, I'm a newbie to the group and our beloved HP6114A, SN 2650A-04940 is starting to misbehave.
It has been rock solid forever but now the output voltage is wanders around the set-point +/-50mv.
Does anyone have a suggestion what the problem might be or would someone qualified be interested in servicing it for us?
Thank You!
Wade

[Vgkid]

Hi, I'm a newbie to the group and our beloved HP6114A, SN 2650A-04940 is starting to misbehave.
It has been rock solid forever but now the output voltage is wanders around the set-point +/-50mv.
Does anyone have a suggestion what the problem might be or would someone qualified be interested in servicing it for us?
Thank You!
Wade

Try scoping the output, though I do think that 50mV is a bit much for a capacitor issue. So it could even be a pass transistor.i think that the pnp pass transistor is not working correctly in mine.
 Interestingly I was talking to a guy named Wade (in Hampton) on Saturday.
Edit: Is this 50mv in a few finutes, or a couple hours. If the latter, could be a power supply issue. Especially since I believe thereference has its own supply.

[wade salt]

Hi, I'm a newbie to the group and our beloved HP6114A, SN 2650A-04940 is starting to misbehave.
It has been rock solid forever but now the output voltage is wanders around the set-point +/-50mv.
Does anyone have a suggestion what the problem might be or would someone qualified be interested in servicing it for us?
Thank You!
Wade

Try scoping the output, though I do think that 50mV is a bit much for a capacitor issue. So it could even be a pass transistor.i think that the pnp pass transistor is not working correctly in mine.
 Interestingly I was talking to a guy named Wade (in Hampton) on Saturday.
Edit: Is this 50mv in a few finutes, or a couple hours. If the latter, could be a power supply issue. Especially since I believe thereference has its own supply.

Vgkid, Were you by chance in Hampton buying a UPS system for your gear? 

[Vgkid]

Vgkid, Were you by chance in Hampton buying a UPS system for your gear? 

Yes. Same Wade then, small world.

[wade salt]

Vgkid, Were you by chance in Hampton buying a UPS system for your gear? 

Yes. Same Wade then, small world.

Small world Indeed!!!

Would you like a repair project?
Soldering must be to NASA standards and we will pay for the repair.

[joeqsmith]

Nice score!   Looks like it had an easy life.

Well look what wandered in the front door.

Why its another precision power supply. It appears similar in rating to the another beloved line, the Power Designs Precision, specificlly the 5020 (though the PD goes to 50V in the second range). Lets see how it compares in a few stats:

....

First, let me say the fit and finish on this thinking is very nice. Brushed aluminum, textured side panels, enameled front. The only plastic comes in the display, the voltage selector and a few knobs and switches. Everything feels very solid and the damn thing weighs a bloody ton. It's things like this that they get the monicker boat anchor.

....

This is HP's version of digital, no knobs to turn. Just push the upper button to increment up one and the down button to increment down one.

....

Quite frankly, being as this device is roughly a decade older than I am, it out right amazes me. Not only for its features at the time. You look at today's supplies and especially the cheap ones don't come near to the qualities of this one. Hell you would think with the schematic being printed directly in the manual someone would have made a knock-off but nope. What also amazes me is that not only is this device made in the USA but ALMOST all of the components are as well. The only ones that I could see that aren't appear to be the Dale resistors which are made in Mexico.

[PaulAm]

When I was fixing the paint on the tens digit switch on mine, I took the zero off entirely.  Now I have leading zero suppression 

[mtdoc]

Three of these have shown up on eBay recently.

The first 2 from the same seller for $47.95 are listed as "for parts or not working". He's gouging on the shipping ($54!). But still not a bad price considering he gives you 14 days to return it (sans shipping).  For some reason he has an ITAR disclaimer in the description (WTF?) but then doesn't ship internationally anyways...

The third one looks the best for $100 and $22 shipping. Very clean and listed as used,  "tested under load", and with 30 day return policy.      If I didn't already have one of these excellent supplies - I'd be buying this one

[bitseeker]

On eBay, it's best to ignore the term "Shipping". The proper label for that field is "Buyer's Premium".

e.g.,

Condition: For parts, not working
Price: $47.95
Buyer's Premium: $51.16
Total: $99.11

Condition: Used
Price: $99.99
Buyer's Premium: $16.44
Total: $116.43

See, now there's no gouging on "shipping". The former listing is just an expensive parts unit.

[Vgkid]

If the shipping was around 30, then it would be reasonable. 50 is almost 2x to much.

[mtdoc]

If the shipping was around 30, then it would be reasonable. 50 is almost 2x to much.

Yeah - the other seller is shipping for $22 and I'm sure they're not losing money on it. I think that is about what mine was to ship as well.

[bitseeker]

Well, I couldn't resist any longer. I got the one with the 30-day warranty. It appears that seller has sold several of these since the last post in this thread. The one I got was as described, but still better than I was expecting.

Cosmetically, it has a few minor scratches, but no dents to the heatsink fins and it still has the rear cover over the programming terminals.

All the voltage decades work well and are spot on. Relative to my calibrated U1252B, it's at most 1mV off. The analog gauge is spot on as well for both voltage and current. Noise is 600-700uVrms. It's rather refreshing to buy something that I don't have to fix for a change.

Actually there is one thing that could use a tweak. The positive binding post is a bit loose.