Good to know
I was always under the impression that it was only
the
DDR myself. I always look at both sides anyway
but still have trouble deciphering these type
DDO / DDRs
anyway. I normaly look with 10X power but still cannot
see the effect. Wide spreads I can pick out but I see nothing
really in the pics. shown. Will have to study them more closely from now on. Wasn't there also
DDO /
DDR on the 1982 ?