The former 6 D channels, were at the beginning of D authorisation (1975), six to the authorisation holders frequencies assigned in the 2 meters amateur band.
D authorisation had been then set up people who used of the illegal 27 MHz AM band, the occasion of offering goes away to make to ' real' radioamateurs. This group 'new' amateurs could use the following frequencies;
145,250. 145,275, 145,325, 145.350, 145,375 and 145,400 MHZ. Modulation were exclusively FM. And there could be exclusively worked with type approved equipment, which could not work outside 6 channels.
A number of manufacturers jumps then. Well-known names such as Kenwood with: TR-2200g en TR-7200g.
Icom with the basetransceiver
IC-21AD and the mobile
IC 240AD.
and the portable
IC-215AD.
But also Clegg,
Zodiac Gemini and
Standard, had brought out a 6 channels TRX.)
The validity of these D license was, original, 2 years, with extension of maximum 1 year. Within this time one had succeed for C authorisation. These conditions kept no score legally and later D authorisation was converted into a permanent authorisation, with indefinite validity. After gaining the examination PD0 the call were granted, where the first character of the suffix indicated when the examination was taken off. Each examination had its own first character. For example; PD0EGF the autumn examination has done in 1977, and everyone who succeeded for that examination got a callsign of which the first character in the suffix was a E. And every that examination did in spring 1981 got a callsign with a L as first character.
As the years expired, the D amateurs got more and more powers and possibilities for their arrangement.
Still later D authorisation was converted into a N (ovice) authorisation
