[Ron Ramirez]

I have a question about the capacitors in Peter's schematic in post #178, page 12, this thread.

I am familiar with pF, nF and uF...but "cm" (C3, C10)? What does that mean?

[RadioSvit]

Good question . I am also looking for a convincing answer. I have one capacitor of 4.5 cm disk design and I measured its capacitance - it turned out about 3 pF. But I well remembered that I dropped it from a faulty receiver, where I changed it to a 47 pF capacitor and then the receiver started working. It is highly likely that it was faulty. Therefore, I have a version that the abbreviation CM is the same as PF, but it denotes ceramic capacitors.

[morzh]

It is my impression that for whatever reason they measured it in...."centimeters" ("cm").

1 cm is a CGSE system 1cm is the measure of capacitance and approximately equal to 1pF.

(I am a physicist and this is how I know. But I never saw anyone using it in electronics before, especially in the same sch where other caps are shown in "pF").

[RadioSvit]

It seems to me, Michael, that сm and pf are the same in the long terms. But the question remains - what is the difference between them?

[Ron Ramirez]

Русский: Я этого не понимаю.
Українська: Я цього не розумію.

[morzh]

Well...this is a sole sphere in vacuum capacitance. Sphere with the radius of 1cm has the capacitance of 1cm.
Only in CGSE and Gauss systems. Approximately equal 1.11 pF.

Now, in CGSM system 1cm is..... inductance. Approximately 1nH.

Just to confuse you more, the unit of resistance in Gaussian system is Second.


Ron,

It is not really complicated but if you want, read on CGS system and its magnetic and electrostatic versions.

[Ron Ramirez]

Fascinating.

   

Just remember, Mike, that the vast majority of us in this hobby fall into the "hobbyist" category rather than the "E.E." category.

[morzh]

Well.....I know. I will tell you even more, most EEs don't know that either.
I'm a physicist, so I do.

PS. I just tried to answer the question about the "cm".
Short answer: same as pF, or for Terry - mmF (or uuF).

[rfeenstra]

Mike, what branch of physics?  I was a physics major in another lifetime. Then got into the church organ business. don't know if that was a good thing, though it served me well.

Rob

[morzh]

Rob

I was a physics major, specializing in solid state physics, but then I chose to go to the experimental/theoretical department as they had an electronics lab and I got a chance to do my diploma project in Electronics.

Again, it was another life

[Arran]

Mike;
  I'm pretty sure that they refer to electron tubes in France as "Lampes" as well, at least that was the terminology they used for them back in the 1920s and 30s in their advertising. It kind of makes sense that they would call them lamps in the USSR, from what I remember the French were one of the Western European countries that the Russian Empire, and later the USSR, seemed to be on reasonable terms with. In fact France and Russia were both members of the "Triple Entente", along with Great Briitain, prior to WW1.
Regards
Arran

[terrylett]

Ron's Mr. Spock bmp was perfect for this discussion.

I remember reading that Powel Crosley contracted engineers from GE and Westinghouse and other powerhouse electronics institutions for support on his 500KW Voice of America broadcasting project and I wonder if maybe a few (or more) of them had a European bloodline and they might have been schooled at a college that used those designations for circuits. Maybe they showed up in some of the Crosley schematics...

Or its just mind control - look at those schematics long enough and you will only buy Crosleys!

[Ron Ramirez]

Mike

I think you took offense where none was intended. I apologize if you did. The "Fascinating" was an honest comment, not sarcastic. It's what Spock would say on Star Trek when he made a certain discovery or encountered something he found interesting (and thus my comment, as I found this interesting).

P.S. You haven't caught up to my post count yet? Get busy, man!

[terrylett]

And gentlemen if I may chime in...

I also had no intention to diminish a posted comment or observation. The Spock image simply brought me back to my adolescence and the days that I was glued to the rabbit eared TV watching Star Trek.

I welcome the input of any individual whose intellect or amassed knowledge blows mine away. The references actually reminded me of my awe of my favorite interstellar objects: neutron stars (black holes get all the publicity).

As far as my rewiring goes the power portion is done and working fine. Thanks again to Ron and Klondike for the assistance. Now I just have to figure out what to do with the 3 side terminal connections that the former owner was trying to do.

Onward through the fog...

[morzh]

Ron

I am yet to take offense at anything here. Especially from you.

I myself saw for the first time the CGSE units (or what I think to be a CGSE unit) being used in an electronic schematic.
Then again..... I'm not too old to claim to have seen it all.