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| My introduction to Litton Electron Devices was with John McCammon's group and Pat-II. Once installed, I was directed to install our new computer interface into our our first Patriot test set, Pat-I. It was next to Pat-II. Installation went fine. I was in the process of calibrating it. Then John was acosted. Big-wig, Don Covert, threw a wad of crumpled-up paper at John, with a burst of emotion. John opened it to see written "What is this Patriot crXp?!" John told me to help group-14. I gathered my tools and followed Don. The short walk took me from an office-environment into what felt like the old west of electronics. Out of the blue, Big Al Williams was grilling me: "Why do you work for such a shXtty company as ETM?" He was deadly serious. His rudeness didn't phase me. They Led me to Jim Blaha's machine, our first "Litton Quad." The "Check-24 V" lamp was lit. I smelled smoke. An hour later I had the obvious failures fixed. Operator, Vic Arnold, pushed the Beam-on button eagerly. The first thing I noticed was a cathode supply that fell short, maxing-out at 29,995 Volts, shy of meeting the 30 KV specification. This told me Blaha was running scared. Unwritten ETM policy dictates all systems be robust. Vic arced the 30 KV supply to some foil attached to a shorting bar. An unusually loud report gave way to uncanny silence. Once again lit, our "Check 24 V" indicator beconed me fourth. Vic looked shaken. The foil was peppered with holes. Smoke wafted out of the cabinet. I said it looked like we'd gotten a dog. Vic said "Woof...woof,woof." I just about died laughing--he said it quite dryly. And so the healing began. Vic's positive energy made each little success count. It was the school of hard knocks. Vic eased me into the swing of things. Baby steps got us through it. |
| The Litton Quads were built for a dual-mode coupled-cavity TWT. These tubes produce high peak power at 3% duty. Or with reduced peak power, 45% is possible. Dual successive shadow-masked grids are driven in unison for the high mode. Only one grid gets driven in the low mode. Westinghouse wanted to offer both in an airborne radar, for the F-16 fighter. Alas, the F-16 went out of production when the APG-66 went in. It now does drug interdiction. Demand never materialized for the tube. But Ron Harriot's crowbarless power-supplys will live on in infamy. Serial number 214 was funky in test. It flopped in the field. Blaha's departure made Chuck rethink his strategy. He needed me shipping cookie-cutters to fund growth. But four more Litton Quads remained to be tested and shipped. There was little room left for anything else in our test area. Chuck called the quads a log-jam. Everything went wrong that could. Our customer, Bud Bedford, knew how to poke fun at wimpy systems. He made his point. But even our beating every spec hands-down wasn't enough. The end users were like high-wire/trapieze dare-devils. Hiltek three-phase HV transformer failures dogged us endlessly. Our own goofball-moves crimped our cash flow ad-nauseum. Things were backing up. Chuck knocked out a wall and doubled the size of our test area. He promoted a flock of tecks from QC to final test. From then on it was nonstop hillarity. But more immediately, I was the new guy, we had a dog, I didn't know what to do. So Gunnar Wik came with me to Litton. A team of senior Westinghouse transmitter-engineers were also flown-in to help. SN-214 worked until it was moved into a new building. Gunnar suspected a "stiff" line. Blaha had blamed a loose connection at the ground peg. I felt intimidated until Gunnar told me to remove the side panels. Then we'd watch while Vic arced it. We would see what was breaking down in back. We would modify to enhance voltage holdoff ability. I'd fix the blown diodes in the relay logic. And we'd repeat the cycle. It was fun. |
| Patriot, and Group 14 |
| The first time we arced it with the panels off, it was really loud. The head Westinghouse engineer said sarcastically "That's some soft supply!" The pass tubes were arcing. Gunnar predicted such might happen. Full raw supply voltage lands across them in an arc. The Cathode/Body regulator uses dual Eimac 8960 glass radiation-cooled tetrodes; rated 50 KV, 1,400 Watts ea. They held off 50 KV cold. But there were tiny spots on the exterior of the anode that glowed bright white. Vic said he'd seen them before and that they called them stars. Sparks shot around inside the envelope when the supply was arced. Gunnar had me add stock ETM low-inductance-resistor assemblies in series. ETM used Allen and Bradley 2 Watt resistors in a series paralell configuration. Then we saw an arc from the terminals of a 10 KV oil-capacitor to its case. It was the output cap for the smallest collector supply, 5 KV output. The supply was referenced outboard the cathode/body supply output- resistor. The case was physically mounted to the case of the cath./body-supply output cap, input to the output resistor. The terminals were referenced to the other side of the output resistor. On an arc, 30 KV landed between the terminals and the case--of a 10 KV cap. The ensuing breakdown bypassed the cathode output resistor, dumping the stored energy into the foil. Most of the voltage usually lands across the resistor in an arc. The energy gets mostly dumped there too (hopefully). Re-mounting the the capacitors apart fixed that. Blasting persisted and it was not obvious why. Ron Harriot had arced capacitors through resistors and knew it should be soft. He looked at the stock ETM resistor board and counted the gaps between traces, measured them, added them up, there wasn't adequate isolation. So we milled out slots to give the boards better voltage holdoff ability. Blasting persisted. The Westinghouse engineers flew home. Gunnar vanished too. Then the cathode/body oil-tank blew. That first tank was what Chuck called the Creme colored tank. Gauss controls made it for a Watkins-Johnsons job. It was canceled. We got it for 20% of the original price. Then the cancellation was cancelled. We sold it to them for full price again. Once again cancelled, we got it again for 20%. Contd. |