Community Forums

PeterFTH · 01-13-2022, 08:57 PM

Back in the '90s I had a non-linear video edit room in my house. A client had music on vinyl so I borrowed a turntable which was sitting on my desk when my niece walked in. She was 5. She pointed to the record player and asked, "What's that Uncle Peter?" I thought about it for a moment then asked her to please leave.

JLRanch · 01-13-2022, 10:16 PM

I still have my metal slide rule and my professional wood slide rule from engineering college in the 50's. I look at them a couple of times each year to test my memory on how to use them. My story is that we sent men to the moon using slide rules for some of the calculations. I have never replaced the batteries or had the screen go blank.

RV Tinker · 01-13-2022, 11:11 PM

Fun reading through everyone's replies. Manage to I.D. most everything in photo (but was hard to see some of them) Photograph album, Flight Log (pilots), Parachute jump log, Tin whistle, Light meter, Panel mount amp/voltmeter, 3 pocket watches, Various vacuum tubes, 2nd panel meter, wristwatch, Slide rule, 3 frequency Xtals, Compass (magnetic) zippo lighter, Deer antler, Resistor, choke/coil, air horn (bulb), Polaroid land camera, and what looks like a FID, but the partial antler also looks like a FID. In '73 I saved up and bought a TI SR10 for use in first year of college. Was bummed that was not allowed to use as it was decided that it was not fair for other students who did not have calculators. Next was a TI SR11 (still have it) then an HP 41C. Obtained about 5 more HP41C's to scavenge parts to keep it running. When finally died, Received an HP 35s (which could do RPN). When I got my first job out of the navy in '82, I think I was hired because I owned an Apple ][. We actually asked our bosses back then if we could have a computer to help with the experiments we were running. Reply was "what do you need a computer for." We were running a set of experiments at the time that was scheduled to take a year to accomplish. Due to some down time and the "magical" procurement of a Prolog Z80 development system from who knows where, we cobbled together an operational system and interfaces to run the experiments. It was all done in machine language. We also didn't tell the higher ups what we were doing. We accomplished the experiments in 3 months.

Needless to say after that we were given a computer system. Never did find out where that prolog system came from.

sj · 01-13-2022, 11:13 PM

I remember learning how to use a slide rule in H.S. Never took another math class.

Taarnac · 01-13-2022, 11:35 PM

Quote:

Originally Posted by Bigd9

Boy you are good!

The two log book were mine from my college days.
The 3 radio tubes are special ultra accurate frequency tubes each with a tiny piece of quart crystal in them. Dad hand made those ultra accurate tubes for the military. All manufactured tubes of the day were compared to those ultra accurate tubes. Each tube has his initials engraved inside them. He also help design and make rugged tubes for use on ships where vibrations from waves, and exploding ordinance would shake the ship destroying ordinary tubes.
The 2 meters again are very accurate ones Dad had a hand in making for the military. There is also a light sensing meter in the picture used for photography.
The "3 transistors" are actually 3 frequency crystals used in two way stationary and handheld radios. When you wanted to change the transmit and/or receive frequency you would install them in the frequency you were looking for. Dad shaped the tiny quarts crystals that produce the frequency.
The "wad of solder" are actually two "wads". One being gold, and the other being silver. These were used to attach the small quartz crystals inside the tubes

.

Here is another one in my collection. Its the size of a basketball. What is it?

As a teenager, I had a set of walkie talkies that used those plug-in crystals to set the (CB) channel that they would operate on, and I still have the slide rule that was given to me by my neighbor who worked for GE high power switchgear and it has their logo on it.

Coincidentally, I'm just setting up an electronics hobby shop in my RV to make use of my retirement time and just came across one of those meters in my breadboarding kit. I believe the one on the left measures milliamperes, but I can't read the one on the right.

In electronics class, we built a scientific calculator from a $10 kit. This was when the Texas Instruments SR-51 (slide-rule calculator) was popular and right after the nixie tube days. Good memories! Thanks for posting that

And sorry, I don't recognize the big crystal.

CW5AVRet · 01-14-2022, 12:29 AM

Remember the first HPs had bright red power-hog LED displays, digital watches too. We engineering freshmen spent a fair amount of time challenging each other with math problems that resulted in an answer of 58008. Then we would turn the calculator upside down and laugh & laugh. Kinda embarrassing what passes for funny when you're 18. No wonder we were in junior college

KanzKran · 01-14-2022, 05:18 AM

Quote:

Originally Posted by NormD

Back in the early days, after slide rules but before electricity was invented, there was the Bohn Context. Depending on the size of the numbers you were working with, and the amount of time available, you could get up to seven decimal places in a division problem. All with no wires, batteries, or solar panels.

I had the kid version of that, which I had forgotten all about until just now. No batteries, no blue screen of death, and pretty fast once you got the knack. That metal loop at the top, aside from being a handy carrying handle, was also the clear ‘button’.

paddykern · 01-14-2022, 05:20 AM

Slide rule was required for HS electronics class.
Instructor drilled us on it daily until we were very good with it.
Years later I taught a radiology physics class.
When a student forgot their calculator and asked if I could loan them one for the test, I would hand them a slide rule :-)

Trapper2022 · 01-14-2022, 05:42 AM

I went through college using a circular slide rule. Like you the cost for an electric calculator was just to high. All my classes had two levels of accuracy that exams were graded on. Boy how things have changed. Safe travels

Enjoy the journey

whiteva · 01-14-2022, 05:58 AM

1970 (ish) Wang programmable calculator using core memory. I still have the large 1' X 1' ferrite core memory board that was in the bottom of the unit. You can see the small magnets with wire wrap in rows. Programs were kept on cassette tapes that had to be loaded before use.

At the underground building of Strategic Air Command USAF, when someone needed to service the unit, two officers had to certify all bombing programs were removed before the unit could be brought upstairs to a special maintenance room for repair. Then they would remain with the unit until repairs were completed. If parts were changed, the old parts were tagged and kept inside the building for disposal. Repair paperwork almost weighed more than the unit.

WOW,, I am one OLD guy!

bobfrommaine · 01-14-2022, 07:36 AM

After the Navy, I applied for a job at a semiconductor manufacturer. The operators used slide rules to calculate yields and the engineers used them to do, well engineering stuff. Later I applied for a job as an engineer working for an older 'inventor' who was designing and building prototypes of all kinds of electro/mechanical devices. During the interview he asked a few questions which required either a calculator or a slide rule. If you pulled out a calculator, you did NOT get an offer. He refused to allow calculators in his office! He could do the most complex calculations on his slide-rule about 5X faster than anyone else could on a calculator. Yah, I got the job.
When I was in Russia, I noted that most of the retail sales people used abacus as their computational device. Again, they could add a series of numbers, calculate exchange rate and calculate discounts faster than I've ever seen done on a cash register.
Bob '14 Winnebago 37F Adventurer; Jeep toad

Holiday1 · 01-14-2022, 07:37 AM

Used a E 6b circular slide rule when getting all my flying licenses

NeverGrowUp · 01-14-2022, 07:50 AM

Slide rule jockey here. . .yes, still have one.
Antler, slr, candle, vacuum tubes, analog gauges . . .

Antique stores are just old home visits

FrankenRV · 01-14-2022, 09:12 AM

I had a slide rule in high school and early college. Then a TI SR-10 "electronic slide rule" in 1973 and a TI-59 (with magnetic strip storage...woohoo) AND a PC-100A thermal printer in the mid-late 70s. After that I went "really big time" and built my first PC (Poly System 88) from a kit (https://deramp.com/polymorphic-computers/poly88.html).