On March 3, 1943, Chief of Defence of the area of Kharkov city, Lt. General Kozlov issued an Order for the 1st Czechoslovak Detached Field Battalion to take up a defensive position in the area of Sokolovo. Forward operating defence was allocated to the 1st Company headed by Telegraph Corps First Lieutenant Otakar Jaroš. He decided to use the steeple of the local church as his command and observation post. Private First Class Hugo Redisch executed the function of observer and telephone operator of the Commander of 1st Company. Both of them were killed in the heroic defence of the church on March 8, 1943. Telephone operator of the signal platoon Private Kurt Steiner was killed in action the same day and wireless operator Private First Class Pavel Fiala was killed one day later. Telephone operator of the signal platoon Private Emil Ketner was also killed in action in the battle by Sokolovo. The battle by Sokolovo was the first hard combat test of the Czechoslovak troops in the Soviet Union. Unfavourable weather conditions and nearly continuous mortar fire made the activity of signal men more difficult so that they could maintain the telephone lines to individual companies only with great effort. Radio operators also achieved considerable success providing continuous communication with the headquarters of superior 25th Guards Rifle Division, with neighbouring and subordinate units. Moreover, they acquired a number of valuable information by monitoring the enemy stations. When some parts of the battalion were enclosed during the retreat and there was no way how to save the communication means and other material, majority of the communication equipment was destroyed by order. However, radio operators succeeded to save the most valuable equipment – the two RB-38 radio stations; they succeeded in carrying the station off the enemy encirclement