Found in a box of books

Want to double your investment? :-)

Mikek

Somewhere I have a pamphlet by Lee de Forest. ...Jim Thompson

-- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | San Tan Valley, AZ 85142 Skype: skypeanalog | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at

fancy scanning it?

Don't know if it would survive being laid out flat... not in real good shape, and apparently suffered some water damage somewhere along the way :-( ...Jim Thompson

-- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | San Tan Valley, AZ 85142 Skype: skypeanalog | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at

right :/ One can always photograph books partway open. I can't help thinking material like that is disappearing rapidly, forever. I've certainly learnt a lot as well as enjoyed reading 20s & 30s electronics books.

NT

I like these old books.

Gosh, Hugo got around.

drool

NT

"Famous"???

I got a set of 4 old tech books for $12 at an antique store a couple of years ago. They all have a name and address written inside the cover, of someone who was attending a local technical school.

"Electrical Illumination" by John O. Kraehenbuehl, Professor of EE, U of Illinois. John Wiley and Sons. (c) 1942, third printing May 1947.

Includes those newfangled fluorescent lamps (and spells it "flourescent" in a couple of places). Has all the theory about light levels, color temperatures, etc, plus practical examples of how to light up your store or your factory.

"Fundamentals of Telephony" by Arthur Lemuel Albert, M.S., E.E., Professor of Communication Engineering, Oregon State College. McGraw- Hill. (c) 1943, fourth printing.

Starts out with the basics and gets through how a mechanical phone exchange worked backed then. The very last chapter talks about how to multiplex lots of circuits onto a carrier system... you can have a type C, which gets you 6 voice channels in 30 kHz, or a type J or K, which gets you 12 voice channels in 140 kHz (on open-wire line!) or

"Electrical Machine Design" by Alexander Gray, Whit. Sch., M. Sc, Professor of EE, Cornell U. Revised by P. M. Lincoln, Director of the School of EE, Cornell U. McGraw-Hill. (c) 1913, 1926, second edition, tenth printing.

A lot of information on how to *make* a motor, generator, alternator, or big utility-size transformer. There are some tables of commercially available equipment; I think probably the 1913 printing was more about rolling your own, while the 1926 revision put more emphasis on when to buy one and when to roll your own.

"Refrigeration" by James A. Moyer, who had a lot of letters, and was State Director of University Extension in Massachusetts, and Raymond U. Fittz, who also had a lot of letters, Assistant Professor of ME, Tufts College. McGraw-Hill. (c) 1928, 1932, second edition, 17th printing.

Discusses refrigerants such as ammonia, CO2, CCl4, and the brand new wonder material from Dr. Midgley, "F-12" (CCl2F2). It is non-toxic, non-flammable, doesn't corrode metals, and mixes with oil! It talks about the guts of household refrigerators at the time, including the GE sealed compressor for SO2 (motor and compressor in same housing), Frigidaire's F-12 system with a belt-driven compressor, and Kelvinator's belt-driven SO2 or F-12 systems. It also shows a Norge system with a rotary compressor, which got popular again in the 1980s.

Matt Roberds

Pseudonym for Louis Martin. I have some old books (somewhere) with that name on them.

Mark L. Fergerson

It would be funny if the whole CFC thing was wrong.

Googling CFC atmospheric lifetimes I found 55 years for -11 and 140 years for -12. You are just going to have to wait a little longer. :^) George H.

John Larkin can't resist denialist propaganda, no matter how silly.

The article points out that we aren't putting any more chlorofluorocarbons into the atmosphere, then wonders why the ozone hole is still there.

As George Herold points out, chlorofluorocarbons have quite a long life in the atmosphere - 55 years for one and 140 years for another - so it's less than surprising that the ozone hole is only slowly shrinking. Steve Goreham doesn't seem to have realised this or - more likely - chose to ignore it i n order to be able to construct yet another denialist myth.

There are a lot of old electrical and radio books in the Google Play Store. You can read them for free.