Mastodawn

5/ I use brass polish to clean a lot of faceplates, mostly because I once lived in an apartment with all brass door hardware, still have the polish, and one day decided to give it a go.
I’m sure there’s a better thing to use, and someone may tell me why using it is a terrible terrible thing, but it’s doing a heck of a job getting decades of cigarette smoke off the face of this thing, even on translucent plastic.
#tektronix #electronics #vintageTech #retroTech

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Paul 2d ago

4/ The prototype unit didn’t work when I first tried it. No real troubleshooting was done
The newer unit had a resistor near the back of the unit that was hanging on by only one lead. This was R563, a 10k 8W, 1% precision resistor off the anode of a tube in the output section.
Funny enough, it wasn’t until I put the units side by side that I realized this resistor was also missing from my prototype unit. It’s kind of a flat, wide, rubberized package that’s near the plug-in connector and is prone to damage.
So that’s a smoking gun as to why my prototype unit doesn’t work.
Now to find a suitable replacement.

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Paul 2d ago

3/ the prototype unit also has factory modifications that seem to correlate to a later rev of the board on the production unit.

Paul 2d ago

2/ One of the curiosities on the prototype of this #tektronix plug-in is the elapsed time meter on the bottom. It is not present on the production unit. There is a note that I cannot decipher with a date or February 16 1966.
This type of indicator is a Mercury Coulometer, and shows time elapsed using a chemical reaction which moves a drop of mercury in a capillary tube slowly and linearly as chemical reaction is caused by the passage of a small, fixed current.
This unit has a large number of reed relays, which have a finite lifespan, and I wonder if this meter was there to measure usage during testing.

Paul 2d ago

1/ the #tektronix #tek3B5 auto-sensing horizontal plug-in: this plug-in for 560 series scopes was arguably one of the first to implement auto-ranging, which would select the correct timebase for a reasonable display of a recurring signal at a given frequency.
I own 2; the one on the left I believe is a factory prototype (thanks Kurt!), and the one on the right was a recent purchase, and clearly smoked a pack a day for the last 40 years. It’s not sticky or smelly, but I don’t know if I’ll ever get it really clean.

Paul 2d ago

Finally used my vinyl cutter for its intended purpose!
#inkscape HPGL is still buggy in Mac, but seems to work… I’ll say less terribly in Linux.

Paul 3d ago

Ooof, #inkscape seems to have a dxf import bug: Mirrored blocks aren't getting picked up correctly (top top is Inkscape import of bottom rhino export).
bug report filed.

Paul 3d ago

I think the moral of the story is vinyl cutters make mediocre pen plotters and Inkscape isn’t a great tool for HPGL.
At some point in the process one of them shits the bed and and draws a line right through the drawing.
Dashed lines also don’t work; I _think_ HPGL has a line type description feature, so maybe it’s the plotter just not accepting it.
On the plus side, I (sort of) finally got HPGL out of OSX Inkscape by rolling back to v1.3.

I wish I could buy a legit copy of AutoCAD R14 or 2000. That’s all I’d really need for this.
#penPlotting #CAD

Paul 3d ago

Andrea Junker

4d ago

Did you know? The word “trumpery” appeared in the 15th century with the meanings “deceit” or “fraud”. 100 years later, it was being applied to objects of little or no value. Then in the 1900’s, it came to mean “showy but worthless”. — Today, it is equated with “fascist shit”.

Paul 5d ago

requiem 🦫5d ago

Favorite line from this permaculture book I just finished: “money is like manure, if you don’t spread it around it stinks everything up”