uuF feaad?

[heathkitman]

Some old schematic that I have been working with have capacitors marked in uuF.
 Is a uuF the same as a pF picofarad?
 Thanks

[AlfBaz]

According to wiki micro, nano and pico were introduced in 1960, maybe micro was before pico 

[c4757p]

uuF is indeed equivalent to pF. uuF = micro-microfarad. micro=10^-6, so 10^-6 10^-6 F = 10^-12 F.

[vk6zgo]

According to wiki micro, nano and pico were introduced in 1960, maybe micro was before pico 

wiki lies in its teeth!

micro, & pico had been around for years before 1960.

uuF were more 1930s & early '40s usage. (note the "u" is a printers best guess for the symbol "mu")

I'm not sure when nanofarads were introduced in Europe,but I don't remember seeing them in any schematics in Australia before the mid 1970s---& that includes German ,Dutch & French equipment.

[c4757p]

wiki lies in its teeth!

micro, & pico had been around for years before 1960.

1960 is when SI was introduced. My guess is that whoever wrote those articles couldn't find a citable resource for the first usage, so the date when they become "official" was listed instead.

[jahonen]

I'm not sure when nanofarads were introduced in Europe,but I don't remember seeing them in any schematics in Australia before the mid 1970s---& that includes German ,Dutch & French equipment.

Just checked and found a Telefunken colour TV chassis service manual from 1971 (presumably). It seems to have nanofarads in the schematic. Couple of snapshots from schematic attached.

Regards,
Janne

[vk6zgo]

I'm not sure when nanofarads were introduced in Europe,but I don't remember seeing them in any schematics in Australia before the mid 1970s---& that includes German ,Dutch & French equipment.

Just checked and found a Telefunken colour TV chassis service manual from 1971 (presumably). It seems to have nanofarads in the schematic. Couple of snapshots from schematic attached.

Regards,
Janne

They can't seem to make up their minds in the first schematic---some of the caps are in decimal parts of a microfarad,& others in nF.

In the '70s, the European TV/Broadcasting stuff I worked on,(LGT,Bosch/Fernseh,Philips,Rohde & Schwarz) would have been a few years old.

Back when most components used in Australia were locally made,"point something uF" reigned supreme,except for Philips caps which used enormous numbers of pF on their first batch of Polyester caps.
For instance,I still have some 10000pf Polyesters in my "Junk box" . 

[jebcom]

In the USA, micromicrofarads was still in common use well into the 1960's, and those books and publications were commonly available well into the 1970's. It takes a while to get people accustomed to new terminology. Sometimes I still have to think twice in order to get "nanofarads" out of my mouth, because when my brain was still pliable, it was either microfarads or picofarads.