Plus ça change ...
I find it fascinating that the high quality typewriter (or whatever it was) that was used to produce those data sheets has a modified character set which includes µ and the funny symbol used for the footnotes on page 1, where anybody else would have used * and **, but does not include Ω, so that it has to be spelt out in full everywhere it would normally have been used.
I'm wondering when picofarads became the normal way of expressing small values. The nanofarad only came into use many years later.
There seems to have been a reluctance to use ρf or pf (or even µµf!) A 1937 issue of WW, selected at random, includes the design for a 4-waveband radio. The parts list includes values as small as 0.0005 mfd (!) and 0.0001 mfd. How much simpler would it have been to use 500pf and 100pf? I was surprised not to find anything smaller, thinking of all the trimmers that would be needed but they cheated! The tuner head was bought pre-assembled, so no values given!
Both a WW and a PW from 1951 used pf although when I first got interested in radio as a schoolboy in the late 50s, it wasn't unusual to find circuits in one quite recent library book I remember that used 0.0005µf tuning capacitors. So, it appears, it was each to his own for a very long time!
However, when the nanofarad first put in an appearance - mid 60s? - virtually overnight, everybody seemed to have adopted it!
Strange old world, ain't it? (Well, I was an Essex boy, weren't I?)
I find it fascinating that the high quality typewriter (or whatever it was) that was used to produce those data sheets has a modified character set which includes µ and the funny symbol used for the footnotes on page 1, where anybody else would have used * and **, but does not include Ω, so that it has to be spelt out in full everywhere it would normally have been used.
I'm wondering when picofarads became the normal way of expressing small values. The nanofarad only came into use many years later.
There seems to have been a reluctance to use ρf or pf (or even µµf!) A 1937 issue of WW, selected at random, includes the design for a 4-waveband radio. The parts list includes values as small as 0.0005 mfd (!) and 0.0001 mfd. How much simpler would it have been to use 500pf and 100pf? I was surprised not to find anything smaller, thinking of all the trimmers that would be needed but they cheated! The tuner head was bought pre-assembled, so no values given!
Both a WW and a PW from 1951 used pf although when I first got interested in radio as a schoolboy in the late 50s, it wasn't unusual to find circuits in one quite recent library book I remember that used 0.0005µf tuning capacitors. So, it appears, it was each to his own for a very long time!
However, when the nanofarad first put in an appearance - mid 60s? - virtually overnight, everybody seemed to have adopted it!
Strange old world, ain't it? (Well, I was an Essex boy, weren't I?)
