Threaded Mode | Linear Mode

emece67 · (This post was last modified: 06-08-2022 07:54 AM by emece67.)

Today I have found this in a drawer at my work:

[img][/img]

[img][/img]

It is dated 1968.

Not sure if it fits in the "HP handheld calculator" category :-)

I'm not sure about its intended use. Apparently it can calculate the rise time measured by an scope as a function of the probe parameters, but the resistance range seems low (up to 10 kOhm) to me (perhaps that was the norm in 1968, but I cannot say). The back can compute the signal loss in the probe.

cruff · (This post was last modified: 10-09-2015 11:12 PM by cruff.)

(10-09-2015 04:53 PM)emece67 Wrote: Today I have found this in a drawer at my work:

The links in the post are not active, and following the url manually doesn't appear to work either.

brickviking · 10-10-2015, 02:45 AM

(10-09-2015 11:12 PM)cruff Wrote:
(10-09-2015 04:53 PM)emece67 Wrote: Today I have found this in a drawer at my work:

The links in the post are not active, and following the url manually doesn't appear to work either.

They're working now, and the advantage of that "calculator" is, it doesn't require any batteries. All it requires is accuracy in setting.

(Post 42)

Garth Wilson · 10-10-2015, 04:48 AM

I get a message saying, "This Connection is Untrusted."

Harald · 10-10-2015, 09:41 AM

(10-10-2015 04:48 AM)Garth Wilson Wrote: I get a message saying, "This Connection is Untrusted."

Remove the s from https://. Then it should work.

emece67 · 10-10-2015, 12:10 PM

Removed the s in https just now.

Don't you see the images "inline" in the post? I do not need to click anywhere to see them.

Dave Frederickson · (This post was last modified: 10-10-2015 01:06 PM by Dave Frederickson.)

(10-09-2015 04:53 PM)emece67 Wrote: I'm not sure about its intended use.

It appears to be a slide rule for determining the measurement error for oscilloscopes based on signal and probe characteristics.

Find the manual for the 'scope pictured and maybe it'll have instructions.

National Semiconductor once gave away similar slide rules for determining transmission line characteristics for PCB design, like trace impedance. I gave a set to a guy at work who collects slide rules and he hugged me!

Dave

Edit: Looks like TI has the calculator, now.
http://www.ti.com/lit/an/snla035/snla035.pdf

TASP · 10-11-2015, 12:08 AM

Nice picture.

I assume we will have 3D printed reproductions available in a few days.

Wink

Thomas Klemm · 11-05-2018, 02:29 PM

(10-11-2015 12:08 AM)TASP Wrote: I assume we will have 3D printed reproductions available in a few days.

It took me a bit longer than that. And it's only 2D printed. And handles only the Pythagorean theorem.

You can print pythagoras-slide-rule.pdf on thick paper and follow the build instructions of my presentation at the Allschwil Meeting 2018.

Kind regards
Thomas