The Radio That Got Entire Platoons Killed in Vietnam D

The very first day, walk into the communications building that they were having the training at. And as I’m walking in, the instructor’s up on this little stage for writing this big number five on this on the blackboard. He says, “Welcome to field radio operator school.” He says, “That number up on the board, that’s your life expectancy in a firefight in seconds.

” And we all look at one another like, “Holy, did he just say seconds?” In 1967, General Creighton Abrams called the AN/PRC-25 radio the single most important tactical item in Vietnam. More important than the M-16 rifle. More important than the Huey helicopter. But the soldiers carrying these radios had a nickname for themselves.

They called themselves dead men walking because that 10-ft antenna sticking out of their backpack wasn’t just a communication device. It was a target. And the North Vietnamese knew exactly what it meant. Kill the radio operator and you cut off an entire unit from air support, artillery, and reinforcements.

You turn a platoon into a death trap. 5 seconds. That was the life expectancy radio operators were told to expect in a firefight. And for 28 young communication specialists who arrived in Vietnam on Christmas Eve 1966, that number turned out to be tragically accurate. This is the story of how a 25-lb radio became the most dangerous piece of equipment in the Vietnam War.

The AN/PRC-25 was developed in the late 1950s as a replacement for the Korean War era AN/PRC-10. It was a technological marvel for its time. Solid-state circuitry, water resistant, 920 different channels, and relatively simple to operate. The military loved it. Over 130,000 units were produced, and in the first 3 and 1/2 years of the war alone, 33,000 were shipped to Vietnam.

But there was a problem. The radio weighed 23 and 1/2 lb. Add the battery and you’re looking at 25 lb. Add an extra battery, which most operators carried, and you’re pushing 30 lb just for the radio itself. Now, stack that on top of everything else an infantry soldier carried. Rifle, ammunition, water, food, grenades, first aid kit.

The radio telephone operator, or RTO, was often carrying 80 to 100 lb through the Vietnamese jungle in 100° heat, through terrain that would exhaust a soldier carrying nothing at all. But the weight wasn’t what got them killed. It was the antenna. The AN/PRC-25 came with two antennas. The 3-ft version was compact and didn’t stand out much, but in the triple canopy jungles of Vietnam, that short antenna was nearly useless.

The signal couldn’t penetrate the dense vegetation. Range that should have been 5 mi collapsed to 1 or 2 km. So, radio operators had no choice. They had to extend the 10-ft long-range antenna, and that antenna sticking up out of the jungle like a flag told the enemy exactly where the American unit was.

And more importantly, it told them exactly who to shoot first. Paul Dwyer was a Marine Corps radio operator who arrived in Vietnam in 1967. Years later, he described his first day of training. He walked into the communications building and saw his instructor writing a big number five on the blackboard. The instructor said, “Welcome to field radio operator school.

That number on the board is your life expectancy in a firefight in seconds.” Dwyer and the other recruits looked at each other. Did he just say seconds? The instructor confirmed it. Yes, I said 5 seconds. So, listen up and you might learn some things that will keep you alive. That 5-second warning wasn’t an exaggeration meant to scare recruits.

It was based on real combat experience, and the North Vietnamese had figured out exactly why killing the radio operator was worth any risk. The North Vietnamese army had a very specific priority list for who to shoot first in an American unit. At the top of that list were three people: the platoon leader, the medic, and the radio operator.

The reasoning was brutally logical. Kill the radio operator, and you accomplish several things at once. First, you cut off the unit’s ability to call in air strikes. American firepower from the sky was devastating to North Vietnamese forces. Napalm, high explosive bombs, helicopter gunships, but none of it mattered if the ground unit couldn’t communicate their position.

Second, you eliminate artillery support. American firebases could rain shells on enemy positions within minutes of a radio call. Without that radio, those guns sat silent. Third, you prevent the unit from calling for reinforcements or medical evacuation. Wounded soldiers who might have survived became casualties, and the rest of the unit was on its own.

The NVA knew something else, too. The radio operator was always positioned right next to the commanding officer. Kill the RTO, and you’d probably kill or wound the CO at the same time. Take out both, and the entire unit loses its leadership and its communications in a single burst of fire.

Jim Singleton, a communication specialist, later told researchers about what happened to his training class. 28 commo specialists from Fort Ord arrived in Vietnam on Christmas Eve, 1966. One week later, 26 of them were dead. 26 out of 28 in 7 days. That’s not a statistic. That’s a massacre. And the enemy wasn’t just shooting at them.

They were actively hunting them. NVA soldiers were trained to identify the distinctive silhouette of the radio antenna. Snipers specifically targeted RTOs. In ambushes, the first shots were often aimed at whoever was carrying that radio. But the North Vietnamese had another advantage that American commanders didn’t fully understand until it was too late.

They weren’t just shooting at our radios. They were listening to them. On December 20th, 1969, American forces captured something that should have terrified every commander in Vietnam. They overran a small North Vietnamese unit called Alpha 3, part of the 47th Tactical Reconnaissance Battalion. What they found in the unit’s logbooks stopped them cold.

The logbooks contained verbatim transcriptions of American radio communications in perfect English. These weren’t summaries or interpretations. They were word-for-word records of what American units had been saying over their radios. Artillery, targets, fire schedules, ambush locations, casualty reports, unit positions, all of it intercepted and recorded by the enemy.

Historian David Fiedler later wrote that no one knows how many lives were lost in Vietnam due to poor communication security, but the number is not small and certainly far exceeds the much-talked-about losses due to friendly fire. The AN/PRC-25 had no encryption capability. Every conversation was broadcast in the clear, and the North Vietnamese had been listening to everything.

American units would radio their positions for artillery support, and hours later, the NVA would be waiting for them. Patrol routes were intercepted and ambushes set up in advance. The enemy knew when and where American units would be before the Americans even got there. Senior American commanders had been warned.

Intelligence officers had raised concerns about communication security for years, but the warnings were largely dismissed. It wasn’t until early 1970 that General Creighton Abrams finally acknowledged the scope of the problem. His response was blunt. “This is terrible. They are reading our mail and it has to stop.” The military did develop an encryption system called Nestor using the KY-38 device, but it came with a devastating trade-off.

The encryption unit added another 25 lb to the radio. Combined with extra batteries to power it, the total system weight approached 54 lb just for communications. Even worse, the system overheated constantly in the Vietnamese climate and significantly reduced the radio’s already limited range.

Most units simply left the encryption equipment behind. They chose to be heard by the enemy rather than carry the extra weight. And when the radios failed at the worst possible moment, entire units paid the price. LZ Albany. It remains the deadliest single-day engagement of the entire Vietnam War. The 2nd Battalion, 7th Cavalry was moving toward a helicopter pickup zone in the Ia Drang Valley.

They had just relieved their sister unit at LZ X-Ray, the battle made famous in the film We Were Soldiers. The men were exhausted after days of heavy fighting. The battalion commander, Lieutenant Colonel Robert McDade, called his company commanders forward for a meeting. And that’s when he made a fatal mistake.

Each company commander brought their radio operator with them. In that moment, the companies lost contact with each other and they had no idea that hundreds of North Vietnamese soldiers were resting in the jungle just meters away. The NVA attacked at 1:30 in the afternoon. Within minutes, the American column was cut into pieces.

Companies couldn’t coordinate. They couldn’t call for artillery support. They couldn’t call for air strikes without hitting their own men because nobody knew where anyone else was. Captain George Forest watched both of his radio operators get killed beside him. Without communications, he couldn’t call for help.

He couldn’t direct his men. All he could do was fight and survive. 6 hours later, 151 Americans were dead, 121 wounded, four missing. It was the highest single day American death toll of the war. 2 years later, at Hill 875 near Dak To, communications failure led to an even more horrific outcome. The 2nd Battalion, 503rd Infantry, was pinned down by heavy NVA fire.

They called in air support. But, the North Vietnamese had a trick they’d learn to use against American air power. When American aircraft approached to drop bombs, the NVA would pop colored smoke grenades, the same colors the Americans used to mark their positions. The pilots saw the smoke and adjusted their aim accordingly.

One Marine A-4 Skyhawk dropped its bomb directly on the American command post. The explosion killed between 20 and 42 Americans instantly, depending on the source. 45 more were wounded. Among the dead was Chaplain Charles J. Watters, who had been moving among the wounded giving last rites.

He, also, was later awarded the Medal of Honor posthumously. The total casualties from the Dak To campaign reached 376 Americans killed or missing, 1,441 wounded. The lessons from these battles should have changed everything, but it would take decades before they actually did. After Vietnam, the military finally addressed the problems that had gotten so many radio operators killed.

The result was SINCGARS, the Single Channel Ground and Airborne Radio System. It did something the AN/PRC-25 never could, frequency hopping. The radio automatically switches between frequencies approximately 111 times per second, cycling through 2,320 different channels. Even if the enemy is listening, they can’t follow the conversation.

By the time they lock onto one frequency, the radio has already jumped to another. SINCGARS was first fielded in 1989 and saw its first combat test in Desert Storm. The difference was immediate and dramatic. But that technology came too late for the thousands of radio operators who served in Vietnam.

Men who carried 25 lb of equipment that made them the most visible targets on the battlefield. Men who went into combat knowing that their life expectancy could be measured in seconds. We don’t know exactly how many RTOs died in Vietnam. The military didn’t track casualties by specialty in a way that makes that number easy to calculate.

But the veterans who served with them remember. They remember the weight of the radio on their backs, the vulnerability of that antenna above the tree line, and the knowledge that every time they keyed that handset, they were painting a target on themselves. General Abrams was right when he called the AN/PRC-25 the most important tactical item in Vietnam. It was.

It connected units to artillery, to air support, to medical evacuation, to each other. But for the men who carried it, that importance came with a cost measured in lives. If you want to understand how other equipment shaped the war in Vietnam, check out this video next. Subscribe for more Vietnam War history.