The Copenhagen Frequency plan of 1948

Names and wavelengths or frequencies on the tuning scale of our vintage radios.

The Copenhagen Frequency plan of 1948

with new and old frequencies

Did you ever look at the tuning scale of your old radio, discovering many names of cities you may or may not recognize? Maybe you have multiple radios where the same name doesn’t match in frequency? Here is some information on the frequencies of stations.

Some history

To cope with ever increasing numbers of broadcasting stations and their increasing (mutual) interference, successive frequency plans were negotiated between countries. They were with their general technical parameters: ⁽¹⁾

• Geneva 1925; 10 kHz spacings on MW;
• Brussels 1928; 9 kHz spacings on MW (10 kHz above 1000 kHz);
• Prague 1929; 9 kHz spacings on MW (10 kHz above 1400 kHz);
• Madrid 1932;
• Lucerne 1933; 9 kHz spacings but not harmonic multiples;
• Montreux 1939; (was to be effective 1940 but never implemented due to World War II;
• Copenhagen 1948; Mostly 9 kHz (8 kHz above 1529 kHz 7, 8, and 9 kHz on LW) spacings but not harmonic multiples;
• Geneva 1975; here most of the stations operate on exact multiples of 9 kHz; the sum of all digits of the frequency will be 9 or a multiple of 9;

Only the Copenhagen plan of 1948 will be commented here after. The others can be found on the internet in more or less detail, sometimes with the complete text.

The Copenhagen Plan became effective on march 15, 1950 at 0200 hours GMT. ⁽²⁾

Participating countries were: Albania, Belgium, Soviet Socialist Republic of Belorussia, People’s Republic of Bulgaria, State of the Vatican City, Denmark, Finland, France, Greece, Hungary, Ireland, Italy, Monaco, Norway, Netherlands, Republic of Poland, Portugal, French Protectorates of Morocco and Tunisia, Federal People’s Republic of Yugoslavia, Rumanian People’s Republic, Soviet Socialist Republic of the Ukraine, United Kingdom of Great Britain and Northern Ireland, Swiss Confederation, Czechoslovakia, Union of Soviet Socialist Republics. ⁽²⁾

Please note that these countries are named as they were in 1948. Today some have become independent or were split up.

Unfortunately, some countries refused to accept the frequencies allocated to them by the 1948 Copenhagen plan. These countries were Austria, Iceland, Portugal, Spain, Luxembourg, Sweden and Turkey. ⁽²⁾

The Copenhagen plan defines the maximum power in each band, the individual transmitting power, the frequency tolerance, the use of directional aerials, directives concerning interference and directives for setting up synchronized networks (multiple transmitters with the same program).

Many models (1950 and later) of public broadcast receivers adhering to the new plan are mentioning this fact on the tuning scale, if only by the word “Copenhagen”.

Sources:

(1) Wikipedia: Geneva Frequency Plan 1975.

(2) The original document “Copenhagen Plan”, archives U.I.T. Genève.

 

The list of radio stations

The lists hereunder are the frequencies of European, north-African and middle-east public radio stations as published by Siera, a sub-brand of Philips. The date of publishing is not mentioned on the document.

It lists every broadcasting station with its nationality, its new – and old – frequency and corresponding wavelengths, as well as its transmitting power.

These lists allows for amateurs of antique radios to compare their tuning scale with the situation before or after 1950. It also allows for name-searching where the scale is partially erased or illegible in order to reconstruct the scale.

Attachments:

• Siera publication of the Kopenhagen Plan - front (250 KB)
• Siera publication of the Kopenhagen Plan - back (233 KB)

To thank the Author because you find the post helpful or well done.

Hi Dirk, thank you for compiling the information.
Here in Switzerland, we do the Beromünster - Budapest Test to check whether the set / the dial is pre or after WWII or whether its Lucerne or Copenhagen frequency plan.

If you start at the lower frequency end of the mediumwave dial and you see Budapest first, and then Beromünster, it is pre war / Lucerne plan,

if you see Beromünster on the lower frequency and then Budapest, it's a post 1948 dial.

Some sets from the forties had the original colourful dials replaced by monochrome dials according to the Copenhagen plan after 1948, these dials were sold for the most popular radios.

So if you have a pre 1948 radio with stations on the dial which appeared later (e.g. a set from 1942 and RIAS mentionned), it will have a replacement dial according to the 1948 Copenhagen plan.

kind regards
Martin

To thank the Author because you find the post helpful or well done.