Thanks for the NIST link, capitalization and spaces are always causing arguments and this is the answer
I think I have written it some time ago but as it closely associate âŠ
In TI datasheet (revision January 2014) of DC/DC converter TPS54061 (and others in that serie) I found parameter âError amp gmâ given as having the value of 108 ”Mhos. During all my electronic live I have never seen such unit name which I read as micro-Mega-Hoses so reducing micro and Mega I get Hoses. It took me some time to discover that Mho is the unit about 130 years ago replaced by S (Siemens). As TI is company from United States I agree with you about level of knowledge of SI.
As there were many small bugs in calculations in that (and others) datasheet I have written them and also asked of using so old units. I got info that after my mails they decided to update all 9 datasheets I was writing about and ⊠see Note at beginning of page 16 in TPS54061 datasheet. But ”Mhos were replaced by ”S 
A guy from Europe here.
I donât find the SI rules suitable for a schematic. At least for my schematics.
For caps and resistors I use the R_small and C_small symbols, so there is not too much room for the value fields.
I use:
10u for a 10 ”F cap. The F is implicitly understood.
3k3 for a 3.3 kΩ resistor
10R for a 10 Ω resistor
Never came across a 1 F cap 
Iâm better I use 10 for 10 Ω resistor.
I donât think you can get everyone else to follow such rules. Of course you might say the same regarding engineering notation. Simplis/Simetrix simulator always uses a lower case âkâ.
At least in the USA mho was replaced by Siemens during my career; the last 45 years. It may be a little newer than that. I think the change was 5-10 years more recent than replacing Kilocycles with KiloHertz.
In my opinion, the 50 mil default text size in the KiCad symbol library is too large. I use 30 mil text and I find it to be very readable as I work on schematics with my 1080 x 1920 monitor. I have also used 15 mil text when I need to shrink it further. I guess the question is whether it can be read on a printed page, and how necessary is this?
According to:
mho was replaced by S in 1881.
If it is true - I donât know. For me since always conductance was in S but before 1977 I probably didnât hear about conductance (I used only resistance).
I have a 1977 edition of Reference Data for Electrical Engineers. In the chapter on units, mhos and Siemens appear to have equal footing. If you look up either one, they say it is equal to the other and did not mention one replacing the other.
At least in the U.S., those of us who first learned electronics on radios that glowed in the dark always saw âmillimhosâ or âmicromhosâ as the unit for vacuum tube transconductance. And it was usually spelled out - the inverted omega symbol seems to have been rare among typography fonts. I believe I first encountered âSiemensâ in a classroom circa 1968 - 1970, either High School or early college, with a comment to the effect that âSiemensâ was used in some European technical literature.
I donât know when a professional organization or standards body proclaimed that âSiemensâ was the proper unit, but it took a while to be accepted and catch on. (My impression is that the change to âHertzâ happened quickly, in just a year or two circa 1967 - '68.) I have some preliminary product data for International Rectifierâs âHexFETâ power mosfets, circa 1977 - 1980, that uses âmhosâ and âmillimhosâ. Several years later the 1982 Databook shows transconductance units as âSâ (Siemens), but with the inverted omega symbol in parentheses beside the âSâ.
Dale
The first book about electronic I have read was âABC Radioamatoraâ There I have first time read about Hz. I had the 1953 edition (older then me):
I found the scan of edition from 1964:
At bottom of page 41 there is 50Hz and 60Hz.
I donât wont to give my head but Iâm sure in 1953 edition there were also Hz.
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Hi, Piotr
I had a quick look at that book. I cannot read Polish but (seriously) those illustrations.are great. On a lighter note, the illustrations towards the front remind me of this:
I committed an error in my previous post. The correct book title is Reference Data for Radio Engineers.
Since I read it the frequency filtering pictures (page 129) left in my head for always.
When I was 9 according to page 92 I wind my first trafo (7 turns primary, 1 turn secondary) and connected it to 220V AC expecting to get 31V output but not got it 
When I was 10 Iâve build my first radio receiver using the schematic at page 326. Were surprised hearing the same station independently of Cs knob position.
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Did we walk the same path? About age 12 or 13 my father made me purchase, with my own money, a supply of fuses for the household electrical system because my experiments were consuming too many fuses.
And a simple crystal radio receiver (and long-wire antenna) confirmed that an entire world existed on the MW band, far beyond where I could go on my bicycle!
Dale
As a teenager I almost electrocuted myself with the valve amplifier I had built. I was holding the chassis and my thumb touched the live contact on the power toggle switch at the front of the chassis. I dropped the chassis. Miraculously I didnât break the valves (2xEL84?) because the transformers were taller. I had a burn scar on my thumb for a long time. I did get the amplifier working.
The worst part was when I later wrote about the experience for a school composition, the teacher picked out my essay from the marked pile and ridiculed it in front of the class, calling it a fantasy. 
Thatâs awful! The teacher did not appreciate that truth can be stranger than fiction. But your original tale was not even that strange. I was building a 750V powered amateur transceiver kit when I was 13.
Regarding teachers: As a child I once had a substitute teacher who told us that we sway our arms when we walk to push air out of the way. I did not know why we sway our arms when we walk but I was pretty sure that it was not to push air out of the way.
Fortunately we had an automatic fuse
But when I connected my trafo I didnât noticed any spark. Seeing no output voltage I concluded âThey had to switch off power just when I wont to do my experimentsâ. Those time switching off power for few hours was frequent in Poland. I was doing it being alone (ill in bed). When my mother came and I told - there is no power she just looked into fridge to take a water off. When my father came he just pushed the button at fuse and asked me what I was doing
When I was 4 years and 4 months old I liked very much to switch on and off the lights at Christmas tree by taking off and inserting the plug into socked. I keep plug handful (not sure how to say it - plug surrounded by my hand). The sockets were very shallow and it happened that my figer was touching both plug pins while they get contact with 220V. Typically adults donât remember what was before they were 6, but I remember few second with my loud cry looking at red line on my finger.
Very shallow means like this:
And a plug like this:
When I was a boy, I used a 120VAC light to read at night. But my mama wanted me to sleep, not read. So I unscrewed the lightbulb from its socket when mama was in the hall. And then screwed it back into the socket when she was in the kitchen or in the living room. (All to avoid the audible click of the lightâs switch.) One night, I forgot I had unscrewed the lightbulb completely from its socket. When I reached inside to screw the lightbulb back into the socket, my fingers instead went into the empty socket and I felt 110VAC. Spasms in my hand caused me to let go.
Once bitten, twice shy.
Iâm not sure if I have written at forum that when doing final calibration of my scope I was shocked by 1100V DC hand to hand (anoda voltage for scope bulb). I was 24 years old so in theory should be not as stupid as child. But only in theory
As I have never done anything with electron tubes I was not used to be care when device is powered.
When shocked I was thrown at chair (I was standing), lost completely my eyesight for 10âŠ20s, and my hands and legs were trembling for next few hours.
To not say again the same:
The use of the upper case letter âRâ comes from International Morse Code and stands for a decimal point in a series of numbers. This is the way the radio operators of the sinking Titanic would have sent their latitude and longitude location. For a capacitor with a part number of ââŠ4R7âŠâ this would be â4.7â of whatever capacitance.
âLarry
Hi, 9V1MI
I cannot say for certain that you are wrong, however I am a former amateur radio operator who used Morse Code. In fact I built an Iambic keyer which worked properly unless it was actually keying the transmitter. (I guess there was too much âRF in the shack.â) I do not remember anything about âRâ being used to indicate a decimal, and the Wikipedia page has no reference to that. But in electrical engineering an âRâ suggests a resistor, so that 4R7 brings to mind a 4.7 ohm resistor. It seems there are so many different options which all have some reason behind them. My father thought of âMâ standing for âmilâ meaning âthousandâ (think Roman numerals); of course to me âMâ indicates âMegâ for million. As a non-programmer user of KiCad and Microsoft office, I find that the ease of importing from a text field into Excel (and then sorting) to be a compelling advantage of scientific notation.