Dutch longwave transmitters.
Several years ago at the Omroepmuseum in Hilversum I bought the book.
Ing. P. Vijzelaar – 70 jaar radio-omroepszenders in Nederland published by Kluwer Teschnische Boeken ISBN 90 201 2522 2   published in 1991

The first private experimental transmitter had the call letters PCGG and operated on 670 m / 448 kHz was in operation until 1924 from a location in The Haggue. Radiated power below 50 watts.
NSF in Hilversum got a license in 1923 and operated on longwave on 1050, 1060, 1071 and 1075 to avaoid interference from foreign stations. Originally on sunday evening with 500 watts. Later 4 kW, in 1925 20 kW. Out of this experimental transmitter grew the time sharing organisations AVRO, VARA, NCRV, KRO and VPRO.
The frequency conference in Prague in 1929 allotted 1875 m / 160 kHz to The Netherlands.A longwave transmitter on 160 kHz was used in Huizen 1927 – 1935 and in Kootwijk 1933 – 1944 with 15 kW. Both were called zender Huzen.A new bandplan of Luzern in 1933 changed the allocation to 223 kHz.
A new frequency plan was discussed in Geneva in 1975. The outcome was the Dutch allocation of long wave 173 kHz (originally intended in co-operation with Belgium in the Delta Plan. The old frequency of 160 kHz was earlier given up in exchange of “exclusive” MW frequencies. Maximum allowed power 500 kW but was never built.

Best regards Karl-Erik Stridh (2023-04-09)