A good night

I have one of these dealies sitting under my workbench a friend gave me, I've been tempted to build some kind of project out of it:

Unfortunately it smells like a battleship! Cosmoline or something like that. Every time I take it out of its protective housing it stinks up the entire room, and it's even worse when I turn it on and it warms up!

I wish I had friends that gave me workbenches.

I love the smell of cosomoline.. my lathe, mill and vacuuum pump all have it.

Maybe a cool display.. clock, digitally-generated Lissajous or something.

Best regards, Spehro Pefhany

bs

Cool, what's the bandwidth? Power it up and put it in the shed for a few days/weeks?.

George H.

obs

Me too! Rifles are covered in the stuff for long-term storage so the metal parts won't corrode. Wiping with a rag soaked in mineral spirits will remove the cosmoline.

Regards,

Michael

Yes, thank you. That friend is not my grammar teacher, apparently. :)

As a kid my father used to take me to see the battleship Massachusetts at Battleship Cove:

The smell always reminds me of her!

I remember reading a quite a while back about a method used for generating letters and numerals on a CRT done in the pre-microprocessor era completely in analog. I can't remember if was based on Lissajous figures exactly; all I recall is that sine waves were fed into complicated looking LCR networks that produced appropriate phase shifts in the X and Y signals fed to the CRT to generate various curves, and these curves were somehow multiplexed into the correct figures. I wish I could remember what book I saw this technique in.

The manual says the vertical amplifier has a DC bandwidth of 0 to 2 megacycles, AC bandwidth of 5 cycles to 2 megacycles. Horizontal amplifier is the same except only to 500k cycles.

My HP9100 programmable calculator, made from transistors, no ICs, had a CRT display. 7-segment, scanned strokes, electrostatic deflection.

I still have two 9100s. Gotta get them working one day.

John

Cute! Not many tubes, possibly just enough for differential drive?

The BK this scope *used* to be was pretty terrible. Three compactrons on a PCB, a late model TV repair scope. SE deflection and really awful linearity (RC sweep). So, I don't even have a sweep circuit yet and I'm doing better. :)

Tim

I guess we can rule out flatscreen TV. :)

Yes, it looks like it has differential drive on both the horizontal and vertical amps. 8 tubes, not counting the CRT and rectifier, all tightly crammed in there in little modules. It would probably be a good scope for hacking because they're nice enough to bring the connections to the CRT plates out to jumpered terminals under a little flap on the back, and it has an intensity input as well.

There's a full schematic in the user manual here:

toobs

me,

p!

Gorgeous.

All done with 40 discrete J-K flip flops.

(Interesting digression: "...Early in the spring of 1967 a skiing injury landed Bill Hewlett in the hospital. [...]" --ibid :-)

-- Cheers, James Arthur

On a sunny day (Mon, 23 Jan 2012 18:47:23 -0600) it happened "Tim Williams" wrote in :

Scope looks nice, you need some 'flyback' suppression in your timebase. (intensity lower when sawtooth returns).

I rather tinker on something usefull :-) I've replaced all the CRT displays in my equipment with color TFT displays.

My most recent project (a TDS644 which I bought with a broken CRT):

Somehow I find that little machine more impressive than the latest intel billion-transistor marvel.

The "32768 bit ROM board"... no not a chip! A 16 layer PCB with orthoganal drive/sense lines... is the board material itself magnetic somehow? No, just lots of little PCB mounted cores I suppose.

Nice - any tips/resources on how to do this sort of thing? Would seem a horrendous task with the LCDs I am familiar with (controllerless STN and TFT).

There's a kit out there, but rather pricey at $600. What did you use for a controller and LCD? Is that moire pattern actually visible?

toobs

One of the ROMs in the 9100 is a pcb, but the coupling is between traces... no cores. There are two more ROMs, one a discrete diode array and one a resistor array.

John

The moire is your monitor. If you view the image full size you can see the pixels of the TFT screen :-)

I feed the digital image data into a PCB with a small Xilinx CPLD. The CPLD converts the image data into color values. Much like the way I modified my TDS510A:

I bought the TFT screen and inverter from Ebay. Price depends on what is for sale on Ebay :-)

Aha of course, it is a *Read only* memory. So what, the bit pattern is the trace pattern? Program patched with a x-acto knife?