Favourite parts with off-label uses?

Methinks you mean the HP P2055DN printer. Here are the setting involved in adjusting the print density and resolution.

  1. Resolution: Set it to "ProRes 1200" for highest quality. If it starts to fill in component holes, back it off to "Fast Res 1200".
  2. RET: Resolution Enhancement Technology. I don't recall exactly what this does, but try toggling it to see what effect it has.
  3. Print Density: Higher numbers are denser or darker. Lower numbers are less dense and lighter. I think higher is what you want.
  4. Econo Mode: Save toner but produces "thin" characters. Turn it off.
  5. Try switching between PCL5c and Postscript. Each has its own "smoothing" algorithm which might affect print density. I suspect PS will be smoother, but incredibly slow to print.

Good luck.

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Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
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Jeff Liebermann
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Jeff,

Many thanks for that input. Pretty sure I've been through all the options previously - definitely Print Density, Econo Mode and Resolution Enhancement. I think ProRes1200 but cannot recall for sure.

I can't see how to switch between PS and PCL5c (using the Mac OSX print dialog to print a PDF).

In addition to a PCB, I had produced a document with a grey-scale rectangle to check the printer, and spent most of a day playing with settings in Kicad, OSX and the printer to get, at the end, a disappointing result.

Kicad users beware: Print and Plot are completely different output modules with very different quality results.

It could be the after-market toner, of course. A genuine HP cartridge is $152 ($280 for high yield), compared to $19 ($25) for after-market. Guess which I chose? Maybe I should try a different cheap cartridge, or take a USB stick to some place where I can try it with genuine toner.

Clifford Heath.

Reply to
Clifford Heath

Two more for the list:

  1. The printer driver has a "type of paper" setting in the "Paper Handling" menu. I don't know what type of paper you're using but try everything from glossy to sandpaper and various thickness. When experimenting, roll the printed page a little to check if the toner has been properly fused to the paper. The toner on shiny glossy paper tends to fall off in large flakes.
  2. Run a test or demo page on the P2055DN from the printer and NOT from the computah. If the demo page doesn't have any "holes" in the large black graphics areas, then the computah print driver is telling the printer to put holes in those areas. To print the demo page (not the config pages), push the "Go" button when the "Ready" light is on and nothing else is printing.

You'll probably need to install a 2nd printer driver in MacOS. One for PS and the other for PCL5c. I could probably figure it out if I had a MacOS machine handy. However, I left my ancient MacBook at my office, which is essentially inaccessible. Sorry.

I'm curious. What part of the resulting prints were disappointing? Much of the print quality is in the toner cartridge, imaging drum, and the fuser. Mostly, the imaging drum. If it's burnt, scored, uneven, or otherwise deteriorated, no amount of adjusting the printer settings is going to produce an even gray scale and high resolution print.

The P2055DN is not what I would consider a good printer. Mechanically, they are difficult to take apart. Electrically, I've seen a few defective and intermittent (crappy soldering) formatter boards on the similar P2015DN etc models. It might be useful to borrow a different printer and see if some of the problems disappear.

Yup. For the P2055DN, print means PCL5c or Postscript. Plot HPGL (actually HP-GL/2), which the P2055DN does not support. Data sheet at: Languages and fonts: HP PCL6, HP PCL5c, HP postscript level 3 emulation; automatic language switching;

NBC... Nothing But Cheapest.

I would try both a different cheap cart and a different printer. The original problem I was trying to address was "holes" in the printed image visible with a microscope. However, reading between your lines, it seems that there might be other problems related to the printer.

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Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
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Jeff Liebermann

I'll try that, but I doubt it will fix the symptoms I'm seeing.

See below.

I don't recall having to install a first printer driver. Maybe I did and just can't recall, it was almost two years ago. Probably Apple automated it.

See Scanned at 1200DPI on a good Epson scanner, the upper band is part of the solid black banner on a test page, the lower section is from part of a PCB.

I can't see the checker-plate pattern in these ones (that might be the

1200dpi setting), just the blotchiness.

Can't etch from it anyhow.

I suspect this drum.

As a user, I don't mind it, it does what I want... except for this, and I'm not blaming HP for that.

No. These are Kicad actions that *both* produce PDF files - no printer in sight at that point.

Hell, the whole printer was only $AU300, refurbished.

I suspect the drum. The whole thing with extended toner was only $AU50. I'll be happy to spend more *if* I know it will fix the problem.

I had such good results with the ancient PH LJ6 and refilled print cartridges, so I hoped for better this time.

Clifford Heath.

Reply to
Clifford Heath

What is the best old HP printer? Prerequisite : Must be old enough to have no DRM in the cartridges, and accept straight postscript, i.e. before the era where the printer itself became loss-making bait purely designed to force users to install gigabytes of "printer driver" mostly composed of spyware, malware, bitcoin miners and advertising platforms?

My LJ4 from 1992 is working fine except that I am really struggling to find replacement cartridges that have not decayed from old age, and I have not yet got around to figuring out how to fix the wiper blades in them. I'll probably eventually get around to learning to do that, but it would be nice to have a backup printer. Also, I'd quite like a printer that can do double sided.

Reply to
Chris Jones

The other noise source used in wideband jammers was a 931 PMT illuminated by a 4 Watt fluorescent lamp via an iris.

Having seen what happens when a student at work uses too much gain or too much laser excitation on a confocal microscope, I can understand and believe in that configuration.

My old RSGB handbook shows festoon lamps and HV rectifier vacuum tubes as noise sources. Evidently Sylvania made a small "end cap" diode designed to match into a coaxial line at one time.

Steve

Reply to
sroberts6328

OK, it's kinda fun to look at the AC behavior of zeners as a function of current. There were some nice long threads here about that back in the

90's?? (Before my time here, but I read the posts with interest... there's also a nice article by McKay (sp?) at bell labs. Hmm searching SED for { Zener-noise (current) } gets a lot of hits. and some thread about 'Zener diode oscillation' in '97. but I couldn't get google to find it for me.

Oh this article,

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George H.

Reply to
George Herold

If I can't Dremel copperclad, I lay out a 4-layer board and order it quick-turn. All that homebrew PCB stuff is messy and tedious, and you wind up with low-res boards with no gold plate, no solder mask, no planes, no plated vias, and no silk. And a lot of drilling.

--
John Larkin         Highland Technology, Inc 

Science teaches us to doubt. 
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jlarkin

It's not that bad, really, and sometimes it's handier than waiting.

Since toner transfer turned fickle I've mostly Dremel'd too. But while toner transfer was working it was a lot faster than Dremeling, with much better resolution, and it was easy to make two or three on a panel.

With surface mount these days I don't drill at all, mostly. A few holes to access the ground side, at most.

How do you make holes? I use an OLD Dremel drill stand that keeps the Dremel fixed & raises and lowers the bed. There's no wobble in it. Doesn't break carbide drill bits. Magic.

It makes a huge difference drilling when drilling is trivial and quick.

Don't use the new Dremel drill presses for this, or you'll snap one bit per hole. On the plus side, I use the broken bits for manual board Dremeling, making fine cuts and traces. They're the bees' knees.

Cheers, James

Reply to
dagmargoodboat

The quick way is to jam the carbide dental-burr cutter into the board. That will do for a quick via. The slow way is to walk down the wall to the lab, where we have a drill press.

I like to use 2-56 hardware as places to alligator-clip to, power and grounds. The holes for them work best with the drill press.

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John Larkin         Highland Technology, Inc 
picosecond timing   precision measurement  
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John Larkin

Me too.

A pity that nobody seems to sell #2-56 angle brackets or standoffs.

Cheers

Phil Hobbs

Reply to
pcdhobbs

I bought a used but mint Cameron Precision drill press a couple years ago f rom a retired machinist. I paid $20 for it. I was stunned to learn that it was a current model that sold for $999.00. They have changed to a DC motor, but this is the same basic tool:

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-cameron-214-series/

Reply to
Michael Terrell

As long as you have a drill press, there's brass turret posts with rivet bases; just put the support block on the drill press axis, chuck the staking tool, and one pull of the drill press handle sets the rivet

They're silver plated, so you can touch 'em with a soldering iron to get the electricl connection just right. They're perfect for an o'scope probe.

Digikey apparently thinks they're VERY valuable, even in tin plate; my stash of the silvered ones is a few decades old. An ounce lasts a LONG time.

Reply to
whit3rd

That's quite a catch! Good show.

A few years ago I bought the base-model mini drill press from Micro-Mark:

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Change-the-belt speed control rather than electronic, and only a simple mechanical height/depth-stop. It works fine for my needs. I've used it for a number of PC-board drilling jobs over the years (both through-hole, and pad-cutting using a diamond-tipped mini hole cutter) and it has done well... I haven't broken a single carbide bit.

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Dave Platt

torsdag den 9. april 2020 kl. 21.40.30 UTC+2 skrev snipped-for-privacy@gmail.com:

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Reply to
Lasse Langwadt Christensen

If by standoffs you mean tubular spacers, those are readily available in

2-56 as male-female, female-female, and unthreaded, in round and hex, in lots of lengths and materials. McMaster Carr has them, for one, along with Keystone (but not M-F, only F-F). However, I couldn't find angle brackets with holes smaller than #4 at Keystone. Seastrom didn't have #2 holes either, but I'm sure that they would love to quote a custom run for you :-).
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Regards, 
Carl Ijames
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Carl

Oh.. I recall these threaded blocks. (2-56) not cubes, rectangular with two 90 degree threaded holes.. but offset so they didn't cross each other. Maybe they were some custom part? like this, but 2-56

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George H.

Reply to
George Herold

I also bought a micro mill for another $20 from the same man. It has a 4"x4" table. A third $20 item was a small belt sander that I gave my dad.

Reply to
Michael Terrell

Thanks, that's useful. Angle brackets are still AWOL as far as I can tell.

Cheers

Phil Hobbs

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Dr Philip C D Hobbs 
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Phil Hobbs

Sigh. Whenever I get into a printer discussion, someone always ask that question.

Most of the early HP printers had easily bypassed or ignored cartridge "chips". HP wasn't sure if they could get away with preventing refilling of toner cartridges and made the chip somewhat optional, easy to ignore, or just clone. However, when HP realized that nobody was actually doing anything against the practice, circumventing the refill "protection" was no longer as easy or possible.

I don't do much with Postscript and have no idea what you mean by "straight postscript".

I would suggest the HP Laserjet 2300DN. It says supports "Postscript Level 3". I've owned and services a few of these, but don't recall if I ever tried Postscript.

The 2003 vintage HP2300DN is not the best printer available, but does seem to meet your requirements. It does have one irritating problem. The foam rubber pads on the solenoids that actuate the mechanicals tend to melt into a sticky goo causing misfeeds. Here's the fix: The web pages are for the HP2200. The mechanical parts are the same. For instructions on how to remove the plastic case covers, see the HP LaserJet 2300 service manual. Start on Pg 109: Hmmm... looks like someone finally made some YouTube videos on the paper jam problem:

I might have a PDF on how to rebuild a cartridge from that era. However, my office is trashed and closed, probably for most of the pandemic. I'll try to let you know if I find anything among my various computers at home.

The "D" in the model number indicates duplex print. The HP2300DN does duplex printing. The "N" means it has an ethernet card. If you want a 2nd paper tray, look for HP2300DTN.

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Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
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Jeff Liebermann

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