TACJAM was an electronics jamming system that was obsolete even before the design left the drawing board. The electronics were transistor technology when isolinear chips were already being used in calculators and PC's were rearing their ugly heads on everyone's desktop. The only thing giving this behemoth life was the fact that the Army had already spent billions to create it and the whole Electronic Warfare (EW) doctrine that went along with it. The whole system, and indeed the whole EW unit designed to use it, were aimed at an enemy that was much too smart to ever be caught in the only type of warfare it could be useful in. If the Soviets had ever taken leave of their senses and attempted to take over Western Europe in a ground war, then TACJAM, Trailblazer, Quickfix, the AN/TRQ32V, the AN/TLQ17A, and indeed the whole EW Battalion and battle plan could be put into effect. Without that leap of reason, they were all useless. Well, I take that back. The intercept and direction finding systems were quite useful in Desert Storm, Bosnia, and other war zones. These systems were passive and could, and did, give the commander unlimited amounts of information. The problem with Jamming systems was that as soon as they fired up, every direction finding radio within 50 miles would point right at them. TACJAM and Quickfix were designed around this limitation with the idea that if the unit were no longer in that position, it would be safe. Therefore Quickfix was mounted on a helicopter, and TACJAM was in a fast deployment tracked vehicle. Quickfix was supposed to fly around the fringes of the battlefield and jam any commander within line of sight. I'm sure that you can see the problem with this as quickly as the intended operators did. If you can see him, he can see you, and RPG's fly a lot faster than a Huey. They didn't even need to be transmitting; the fact that a helicopter was near you was enough reason to shoot it down. The platform also gave the system another limitation. No matter how much shielding you incorporated in the helicopter's electronic systems, if you sent out a big enough RF signal you would stand a good chance of shooting down your own ride. This kept the power of the Quickfix down to the point of near uselessness. The fact that they were constantly moving also made the use of a log periodic antenna untenable. The log periodic antenna, when used in transmitting, has the benefit of increasing the on target strength of the transmitter by a factor of anywhere from 5 to 20 times depending on the frequency and distance. Keeping one pointed at a target from inside a helicopter flying as fast as the pilot can make it go while trying to avoid the fucking SA 8's he knew were in the area was impossible. Therefore the power output on target was barely more than that of the radio they were trying to block, and it wavered so much that most of the intended signal was still getting through.

TACJAM was built on an old tracked ammo carrier chassis. It had been refurbished and modified to carry the 5-ton system. Part of the refit was to mount a 60 KW 3 phase generator within the chassis to be run through a power take-off by the track's diesel engine. The biggest problem with this was the fact that the generator required the engine to run at a very high rpm and was noisy as shit. It also made the engine reach its allotted amount of hours before maintenance at a rate ten times faster than any other vehicle.

Within the hull of the vehicle was the TACJAM hut. The system was designed as a jamming suite with three high-powered transmitters utilizing a log periodic antenna. The antenna was mounted on the top of the hut and was elevated with a hydraulic mast to a height of 40 feet. The mast could deploy within about 90 seconds.

Underneath the hut and also mounted within the hull was the refrigeration unit. Not an air conditioner, although it had that function as a side benefit. The transmitters within the hut were very powerful, and that much power produces a lot of heat. Without a dedicated cooling unit the transmitters would fry in their own heat within minutes; incidentally cooking the operators as well. This cooling unit took 50 gallons of glycol and was prone to breakdowns. Two thirds of the time that TACJAM was down was due to the cooling unit. The other third of the breakdowns were caused by the ancient track vehicle, which was being used well beyond its design specifications.

All controls for the system were within the hut, with the exception of the 'scram' control. This was just behind the cab of the track and pushing this lighted button would lower the antenna into stow position with 30 seconds. This button would also notify the operator within the hut to bug out and he, or she, could be ready to roll by the time the antenna was stowed. The idea was that within 120 seconds of being told to move, the TACJAM squad would be moving. Unfortunately the travel time for a Katusha rocket from 5 miles away was about 90 seconds, leaving the squad just entering the cab of the TACJAM as the missiles arrived on target.

With three active transmitters and a very complicated operating system a good operator could keep a commander out of the communications loop for as long as the system survived. Jamming up to 9 frequencies with as much as 10,000 watts of directed power would wreak havoc on command and control; at least this was the theory. In actuality it would need to be a very important mission to justify sacrificing the TACJAM and the squad. By the time the analysis units could possibly determine that such a mission was viable, it would be way too late, the opportunity would have been lost.

Proper use of jamming resources would also require a dedicated analyst at the intercept and direction finding platoon. This person would have to have a liaison officer to the division commander to determine just what receivers they would want jammed. The unfortunate fact was that most liaison officers were picked for this job because no one could find something useful for them to do that would keep them out of the way and unable to fuck up anything. They tended to look at the battlefield as they would a sand table model and say, jam this guy, I don't want him to talk to anyone for the next couple of hours. Sounds good, right? Remember that I said that the liaison would need to determine the receivers he wanted jammed, because you jam receivers, not transmitters. Your signal works because it overpowers the enemy transmitter at the receiver; to do this you point at the receiver, not the transmitter. If the receiver has not transmitted so that the direction finding platoon can locate him, or you can't see him, then you have no way to know where to point your antenna. Nine times out of ten missions given to jamming teams are not feasible. There is not enough information or the mission is simply not possible to perform as ordered. The best use of jamming units would be to give them a specific type of traffic that you wish interrupted at a specific time. This would hamstring the enemy at the time of your choosing. I was in MI for 18 years and I never got a mission of this nature, even when I was the liaison to the division commander and even after I wrote the tactical manuals and training aids for the use of jamming assets. Not me alone of course, I was a member of the writing team. The only people who responded to our missives about the manuals were peons hoping someone in authority would read the damn things.

All of this is ancient history. The last time I was in a jammer was over 20 years ago and that was to scrap it.

I have given you this brief precise of EW to let you know that the story following had to have happened in a different world; one in which the tactical EW assets of an EW Battalion were used in combat and used properly. Obviously that has never happened in this world.

Terminology: TACJAM, Tactical jammer mounted on obsolete tracked ammo carrier.

TRADOC, Training and Doctrine Command, in charge of all Army training

RDF, Direction Finding or Radio Direction Finding, three or more radio receivers tuned to the same frequency at the same time, able to give an azimuth to the transmitter and by combining the azimuths, a location.

AN/TLQ17A, a small portable jammer designed to mount in the back of a jeep or HUMV and use a tunable whip antenna or a bumper mounted log periodic entenna. Tows a 3KW 3phase generator to power the system.

Quickfix. A TLQ17A jamming system mounted in and powered by a UH1 helicopter.

AN/TRQ32V, Turkey 32V, A direction finding and intercept system designed to be powered by the vehicle it is mounted on, either a chevy pickup or a HUMV. Combines with other 32V's to form a direction finding net.

Trailblazer, A track mounted system for intercept and direction finding, systems deploy and interlock for an RDF net.

OCS, Officer Candidate School

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Story tagged with:
Ma/Fa / Military /