FS: HP 6114A Precision Power Supply - Page 1
Forum section: electronics / general

author: timb
author_rank: Super Contributor
timestamp: April 13, 2016, 10:50:11 am
content: Up for sale is a fully restored vintage HP precision supply. It does 20V@2A and 40V@1A. I spent close to 40 hours making this thing look like it just left the HP factory. I'd love to keep it, but I need to free up some space and could use the extra cash for another project. (Plus I've got another one!)Here's a list of what I did to her:---I completely stripped the unit, entirely removing the frame, panels, rear heatsinks, front panel and trim; I then vigorously scrubbed it all clean, rinsed with clean water followed by a distilled water rinse and let it all air dry.The knobs and push wheel switches were cleaned in a similar manner; everything plastic (including the push wheel housings and meter trim) saw an application of Mother's Back in Black; the meter's clear plastic window and push wheel switch windows were polished with a high end plastic polish to remove light scratches and swirls.Replaced the old mica transistor insulators and thermal goop with space age Sil Pads.I replaced the two large Sprague Compulytics with identical (barely) used versions pulled from some other gear.Replaced the broken banana terminals with gold plated flush mount banana jacks from Pomona.Replaced the single turn "Over Voltage" pot with a NOS three turn pot.Replaced the 10-turn current pot with a brand new Bournes 10-turn pot; I also replaced the old worn out "DeccaDial" with a brand new unit. (Yes, they still make these; you can buy them on Digi-Key even!)I replaced both indicator LEDs with new, slightly brighter diffused LEDs.---Finally, after reassembling and calibrating the supply I did a full week burn-in, alternating between the 20V *and* 40V current limits. This thing works great!I'd like to get $250 for it and I'll even throw in free shipping for those in the US!I'll try to get better pictures today if it's not raining. For now, here's a couple of quick shots:

author: bitseeker
author_rank: Super Contributor
timestamp: April 13, 2016, 05:06:35 pm
content: Beautiful job, Tim!

author: 0003djc
author_rank: Newbie
timestamp: April 14, 2016, 07:56:20 pm
content: How much do you want for it?Sent from my iPhone using Tapatalk

author: timb
author_rank: Super Contributor
timestamp: April 14, 2016, 08:37:09 pm
content: Quote from: 0003djc on April 14, 2016, 07:56:20 pm$250 with Free Shipping in the US, but I'm open to offers/partial trade as well.

author: ArdRhi
author_rank: Contributor
timestamp: April 24, 2016, 05:44:50 am
content: What plastic polish did you use on the clear plastic? I've got a couple of things with scratched up clear plastic that could stand some polishing.

author: Po6ept
author_rank: Regular Contributor
timestamp: April 24, 2016, 06:52:18 am
content: Quote from: ArdRhi on April 24, 2016, 05:44:50 amI recommend the Novus plastic polish kit. Amazon has it for $17 here is the US. They call it the Novus 7100 kit. I have used it on meters and and radio displays and it works well.

author: timb
author_rank: Super Contributor
timestamp: April 27, 2016, 11:14:44 pm
content: Quote from: ArdRhi on April 24, 2016, 05:44:50 amI useMeguiar's PlastX. It's cheap, available at Wal-Mart and works very well.I also like the 3M Headlight Restoration kit, because it included three sanding disks of progressively smaller sized grits. They're basically little neoprene pads with some sort of woven nylon fabric on each side. The weave goes from loose/coarse to tight/fine, just like sandpaper. I use these to remove semi-deep gouges and scratches on clear plastic analog meter covers, for example.I started writing a restoration guide awhile back, I need to finish it one of these days. Here's a snippet from my section on clear plastic restoration (this deals with removing a deep scratch in the plastic, but the final step shows how to use PlastX; the steps with the 3M sanding disks can also be used for moderate scratches). Please excuse any spelling/grammar/formatting errors, I haven't reviewed this section yet.QuoteFor all other plastics, I use Mothers Back in Black, which is an absolute miracle worker! As plastic ages (especially black plastics) it will fade or turn ashy, more so if it's exposed to significant amounts of UV (think black trim or bumpers on a car). Back in Black removes the surface oxidation and leaves a permanent film that blocks UV to prevent further damage. Think of it as sunscreen *and* skin lotion for plastic.Despite the name, Back in Black works on *any* colored plastic, not just black plastic.

author: bitseeker
author_rank: Super Contributor
timestamp: April 28, 2016, 01:48:00 am
content: Here ya go, Tim. Grammar, etc., refurbished.Just copy + paste.-----So, let's say we've got a 4" x 3" meter cover with a 2" scratch in it that's 100mils deep. What I do is start with 3000-grit dry sandpaper. I start sanding the *entire* 4" x 3" cover. You can't just sand out the scratch itself when it's deep like this, because you'll end up with a noticeable "valley" in the plastic.We sand *evenly* in a back-and-forth motion with 3000-grit paper, until the scratch *just barely* catches your fingernail when run over the plastic. Basically, instead of filling in the scratch, we're trying to sand down the rest of the plastic to the scratch's deepest level.At this point, the cover won't be clear anymore. It should look diffused. Now, you switch to 5000-grit silicon carbide wet/dry paper. Fill up a small bucket or the sink with water and start sanding *underwater* in a circular motion with even pressure until your fingernail no longer catches on the scratch.Now, we switch to 10000-grit silicon carbide wet/dry paper and continue sanding underwater until the plastic starts to become clear again.Then, you move to the 3M fabric sanding pads, wet, but not underwater. Spend a few minutes with each pad (from coarse to fine), making sure to rinse the plastic off when changing to the next pad. We want to remove the microscopic plastic pieces ("plastic dust") in order to minimize tiny "swirl" scratches); use a "wax on, wax off" technique.Now, you should be left with a mostly clear plastic cover. It will, however, have some swirly scratches in it, but that's okay. We'll fix those now, in our final step.Apply some PlastX to the cover and, using a balled up Chem-Wipe, begin buffing the cover in a circular motion. You'll most likely need to use several Chem-Wipes. After the first one gets soggy and starts to come apart, switch to a new one, buff a bit, then a new one. After awhile, the cover should be dry, clear, and free of scratches and swirls!Note: Absolutely do *not* use a paper towel, toilet paper or even a cotton/micro fiber cloth for the above PlastX step. The former paper products are abrasive and the latter cloth products will contain lint and debris, no matter how clean you think it is, which is also abrasive. I only recommend dry Chem-Wipes for this step! If they're good enough to clean $100,000 microscope optics, they're good enough for you.That's it! I've used this technique to remove deep gouges and crazy scratches from several clear plastic covers. Unless the plastic is actually cracked it *can* be fixed. Depending on how deep the scratch is, it can take anything from a single 10-minute application of PlastX to a full 3-6 hour sanding job to fix. All you need are the right supplies, a little time, practice and patience.-----

author: timb
author_rank: Super Contributor
timestamp: April 29, 2016, 08:09:55 pm
content: Quote from: bitseeker on April 28, 2016, 01:48:00 amSweet, thanks! I've actually got a large amount of the guide (mini-book really) written, it's just a matter of going through and editing, polishing, adding pictures, etc.I'll have to get you to proof read for me!

author: bitseeker
author_rank: Super Contributor
timestamp: April 29, 2016, 09:10:15 pm
content: Sure thing. When you've got it where you want it, I'll proof it for ya.

author: idar66
author_rank: Newbie
timestamp: May 17, 2016, 10:05:49 am
content: hi is this unit still for sale, as i would be happy to give it a good home, i love what you have done to it so id be happy to pay price and postage, cheers idar

author: timb
author_rank: Super Contributor
timestamp: June 04, 2016, 11:48:35 pm
content: Quote from: idar66 on May 17, 2016, 10:05:49 amSorry I missed this. Tapatalk didn't bump it up to the top of my list. I sent you a PM if you're still interested.

author: TerraHertz
author_rank: Super Contributor
timestamp: June 05, 2016, 06:20:05 am
content: I'm definitely going to have to get one of these. But I want one that is scratched up and dirty, to match my other gear.Beautiful job restoring it, and thanks for the plastic polishing guide.