During the struggle against the British authorities prior to the establishment of the State of Israel, each of the three Jewish resistance movements, Haganah, Etzel and Lehi, operated clandestine shortwave radio stations meant to circumvent broadcasts by Kol Jerusalem, the radio station run by the British Mandate in Eretz Israel.
This station, which began broadcasting in 1936 in three languages (English, Hebrew and Arabic) was subject to British censorship and could not utilize its Hebrew programs to broadcast national and political messages. The resistance radio stations took it upon themselves to bring listeners vital and uncensored information, accompanied by material related to the unique activities of each movement.
Etzel, Kol Zion Halochemet (Voice of Fighting Zion)
The first resistance radio station to begin broadcasting was Etzel's Kol Zion Halochemet (1939). The station broadcasted on and off until after the establishment of the State of Israel. In March 1944 the station was captured by the British secret police, but resumed its broadcasts in June 1946.
The content of the station's broadcasts was similar to the Etzel proclamations that were distributed and hung on walls throughout the country, calling for the expulsion of the British and the establishment of an independent Jewish state.
Shortly before the establishment of the State, the station changed its name to Kol Hacherut (Voice of Freedom).
Haganah, Kol Yisrael (Voice of Israel)
The Haganah's radio station was called Kol Yisrael and it began broadcasting in the winter of 1940. After only three months, as Britain's Middle Eastern battlefront positions deteriorated due to the fall of France and Italy's entry into the war alongside the Germans, broadcasts were halted. They were renewed in the autumn of 1945, with the establishment of the Jewish Resistance Movement. On the eve of the establishment of the State, the Haganah operated a number of radio stations simultaneously: Kol Yisrael, Telem Shamir Boaz, Kol Hagalil, Kol Hamagen Ha'ivri (Jerusalem) and Kol Hahaganah (Haifa).
On Independence Day, the newly established state's national radio adopted the name Kol Yisrael.
Lehi, Kol Hamachteret Ha'ivrit (Voice of the Hebrew Resistance)
The Lehi's radio station was initially (1942) also called Kol Zion HaIochemet. The name was later changed to Kol Hamachteret Ha'ivrit and during the last year of the struggle, its name was changed yet again to Kol Lochamei Herut Yisrael (Voice of Israel Freedom Fighters). In February 1946 the British discovered the station and arrested its operators, including broadcasters Geula Cohen and Natan Merfish. Geula Cohen managed to escape from prison and resumed broadcasting.
All of the resistance radio broadcasts were conducted secretly and posed a great risk to their operators. Most of the transmitters were encoded inside suitcases that were moved from place to place. Broadcasts were generally short, lasting only 5-10 minutes, in order to prevent the British from pinpointing the stations' locations.
In 1948 the resistance radio stations cleared the airwaves in favor of the national Israeli radio — Kol Yisrael.
Dr. Mordecai Naor