"Ron(UK)" wrote:

N Cook wrote:
Does anyone know of any standard or authorative source for such
designations.
eg
50KA - lin ?
50KB- log ?
50KAB - lin/log , semilog?
50KBA - log/lin ?
and does a B prefix mean a centre pick off fourth terminal, or 1/3&2/3, or
any fixed track tap terminal or what if anything a B prefix means. ?
And while at it any other letter designations eg for cosine track, or even
wire/wound etc

I think it`s A = lin, B = log except when it isn`t

the marking conventions changed some time ago

There are no meaningful conventions except that C universally means 'reverse log'.

Graham