On the 75th Anniversary of Operation Overlord, let’s remember D-Day radio action on the beaches.
Recently, I wrote a few articles about early 2 meter FM equipment and its use in public service activities. As we approach the 75th anniversary of the Normandy Invasion, I thought it might be fun to remember some of the wireless sets used in June, 1944.
D-Day radio action saw the use of many field and portable radios. You can see some of these in the picture above.
Top center is the iconic SCR-300 backpack, perhaps the most useful FM walkie-talkie of all time. You can spot this rig in most American WWII movies featuring infantry action. The SCR-300 weighed in at 30-40 pounds, depending on which battery was installed.
U.S. signals made early and extensive use of FM, frequency modulation. Any ham will tell you why FM is superior to AM for short-distance communications. You can see the SCR-300 a lot in Saving Private Ryan. Operating at the low-end of VHF (40-48 MHz) this walkie-talkie had a range of a few miles with output of 0.3 watts.
At the right, you can see a soldier talking on the SCR-536, the first modern handie-talkie. It weighed five pounds and was waterproof. Pulling out the antenna turned it on. Output power came in at 400 milliwatts with AM operation between 3.5 to 6.0 MHz. Range was 1-3 miles.
D-Day radio action with higher power featured less mobility and receiver/transmitter combos. These included the SCR-284 portable field radio (left) at 17 watts AM or CW over 3.8 to 5.8 MHz. Three strong men were needed to carry it into position. Upper left is the British/Canadian Wireless Set Number 19. You would be fascinated by this radio as it combined HF (2-8 MHz) with VHF (229-241 MHz). This rig ran in armored vehicles providing long distance, local tactical and intercom communications.
D-Day Radio Action was a huge effort
Just think about it. Nearly 200,000 troops, 5,000 ships, 8,000 aircraft and around 90,000 transmitters – all operational at Normandy and the English Channel.
D-Day radio action required huge coordination of scarce frequencies. If you read the history, you will notice that requests for frequencies in the early planning stages outnumbered available frequencies by 7:1. Gradually, this was whittled down, in particular by reducing channel separation, sharing frequencies and reducing transmitter power.
Most of the portable radios required crystals which needed to be manufactured in America, shipped, assigned and distributed to operational units.
When all was said and done, everything worked pretty well.