U.S. Naval Cryptologic Veterans Association

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Transit to Operations Area

Once the ships left Pearl Harbor, the SECGRU division CTs unpacked their gear in their assigned berthing areas and reported to the Telemetry room for a general mission briefing. We next unpacked our chests of TEXTA, TECHINS and crypto keycards. The CTO-branchers worked with the ship’s Radiomen to get our secure communication up and running. We also unpacked our boxes of snacks and stowed sodas in the overhead air conditioning ducts. The sodas had to be well secured to keep them from rolling around and possibly disappearing into the ductwork. When that was finished, we started practice and training sessions for the telemetry operators while the [REDACTED] intercept operators manned their positions. Training now had an extra degree of realism as the CTs had to cope with the ship’s motion, noise and vibration.

One of the most difficult parts of the training for the CTs was learning to rapidly acquire, recognize and properly tune the telemetry signals. Speed was of the essence, since final portion of the missile trajectory lasted only a few minutes. There was also an interruption in the telemetry signals during reentry when ionized plasma formed around the warhead and blocked the radio signals for a minute or two. Reacquiring the signals after this blackout was critical as some of the most interesting telemetry was at the end of the trajectory.

We had some training tapes we could play back on the high-speed recorders to familiarize the operators with the telemetry signal sounds and their appearance on the oscilloscopes. However. that didn’t help the operator with the critical step of finding and properly tuning the radio receivers. With the help of my CTTC, I came up with a workaround that helped the operators get the full telemetry intercept experience. The test position at the end of the room had an amazing array of signal generators, mixers and amplifiers. We set up one signal generator to mimic several of the Soviet (Pulse Width Modulation (PWM) and Pulse Position Modulation (PPM) telemetry signals. When the Chief agreed that they sounded about right through the headphones, we fed the signals into the modulation input of a VHF signal generator. We could patch this signal into the RF inputs of the telemetry intercept positions with varying RF frequencies so that the operator would have to find and properly tune the signal. The problem with this method is that the telemetry signals were strong and clear and the only signals that showed up on the receiver.

I took this method one step further and suggested that we broadcast our simulated telemetry signal through a spare antenna at very low power. We weren’t really set up to broadcast signals. However, even with antenna mismatches and a very low power RF signal, I thought there would be enough signal for a test. We didn’t want to test this in port, as even low-power signals on known Soviet frequencies might draw some attention from other ships. We certainly didn’t want to try it when close to Soviet tracking ships during an operation as it would reveal too much about our knowledge of their operating frequencies and telemetry modes. We finally tested this training method out while at sea in transit to a collection operation.

The simulated signal training worked surprisingly well. The operators got to work through several reentry scenarios in an hour. They had to use their receivers with their usual antennas. The Chief and I could vary the signal strength and frequency and could even simulate the plasma blackout by shutting down the signal for a minute. I don’t know whether the CTs on the other DEs adopted this method—we only perfected it on my last operation in February of 1974.

One consequence of this testing of the full signal-acquisition chain was that we found that we had a bad preamplifier in the junction box just below the omnidirectional antennas at the top of our intercept mast. While we had a spare pre-amplifier, the weather was bad, and our maintenance tech was not only seasick, but had a fear of heights. On the theory that I shouldn’t ask anyone to do what I wouldn’t do myself, I volunteered to climb the mast and replace the preamp. I reminded the Chief that I had earned my tweaker and spent a lot of my teenage years building tree forts sixty feet up in in second-growth redwood trees. I had also recently taken a basic rock climbing course while on leave in Yosemite, so I knew how to harness myself and tie off below the preamp box. The maintenance tech had spent three months with me on the WHEELING the previous summer and was confident that I could accomplish the repair. (He’d had no similar issues on the WHEELING. The WHEELING had minimal roll, the weather was good, and our antennas were only about 10 feet above the deck.)

I briefed the CO and asked for a course that would minimize the ship’s roll. Once we steadied on that course, I climbed the mast, tied off to allow me to use both hands, and started the repair. The repair consisted of opening the preamp box, disconnecting and removing the bad preamp and installing the replacement, then closing the box. I think it took me about 30 minutes. Soon after I tied off, I found that the course with minimum roll was directly into the wind and I was getting a strong dose of diesel fumes from the after stack. I yelled down about the fumes and asked for a minor course change. That reduced the fumes but increased the roll.

As soon as I mentioned the fumes, all the onlookers moved upwind in case I puked. That didn’t happen, but dropped tools or parts were still a hazard. When the repair was complete, I asked the CTs to verify that the antenna and preamp were working properly. That took about five minutes, during which time I hung on and enjoyed the view.

When I got back to the deck, I was a bit unsteady on my feet and had the jitters from the adrenaline rush. We all retreated to the Telemetry room and I had a celebratory Pepsi which had been cooling in the AC ductwork. The sugar and caffeine didn’t cure the jitters and I think I was babbling a bit.

It turned out that the omnidirectional antenna and repaired preamp were responsible for a lot of our success in recording missile telemetry later in the mission.