scoonts.theminotaur-第27节
按键盘上方向键 ← 或 → 可快速上下翻页，按键盘上的 Enter 键可回到本书目录页，按键盘上方向键 ↑ 可回到本页顶部！
————未阅读完？加入书签已便下次继续阅读！
coat of thin whitewash had been applied over a still legible Grange hall sign。
〃You'll see；〃 Fritsche assured him。
Samuel Dodgers was a stringy man in constant motion。 He stood in the small； dusty chapel and tugged at this； gestured at that； reset the Dodgers baseball cap on his balding dome for the hundredth time； pulled at his trousers or ear or nose or lower lip； moving； always moving。 〃So you fellows wanta see it again； huh； and see what progress looks like in the late twentieth century？ When do I get some money？〃
〃You got your last check two weeks ago。〃
〃I mean the next one。〃 He hitched up his pants and reset his cap and looked from face to face expectantly。 The sunlight ing through a dirty windowpane fell on a long； lean face。 His chin jutted outward from almost nonexistent lips。 Above the grim mouth was a sharp nose and two restless black eyes。 〃The next check…when？〃
〃I think it's a couple months away；〃 Fritsche replied gently。
〃If I weren't a Christian I'd cuss you government people。 Your tax people squeeze the juice right out of a man…a man who's sitting on the biggest advancement in military technology since the horseshoe…but the giving hand is so all…fired parsimonious； stingy； miserly。 You people are just cheap！〃
〃You're being paid according to the contract you agreed to； Dr。 Dodgers。〃
〃Get a man over a barrel and squeeze him。 It's a sin to take advantage of a man trying to do the Lord's work like I am。 A an。〃
Jake glanced at Helmut Fritsche。 He appeared unperturbed。
Dodgers led them between a dozen or so folding chairs toward the door near the altar。 〃Praise the Lord and pass the ammunition；〃 Fritsche muttered just loud enough for Jake to hear above the tramping and scraping of heavy feet on the wooden floor。
The back half of the old Grange hall was a well…lit workshop。 Several strings of naked hundred…watt bulbs were woven through the joists and cast their light on a crowded jumble of workbenches； tools and junk。 The visitors picked their way through it behind Dodgers； who approached the only person in the place； a young roan of about twenty with carrot…red hair and acne to match。
〃My boy Harold；〃 Dodgers said to Jake； who shook the offered hand and introduced himself。 〃Harold was at Stanford； but they weren't teaching him anything； so he came back here to work with me。 Learn more here with me than he would in that Sodom of little minds。 Those fools with their calculators； always saying that something won't work。。。〃 He continued to fulminate as he opened the large doors at the back end of the building and began stringing electrical cords。 〃Well； Helmut； you seen this done before。 Don't just stand there like a tourist。〃
Dodgers drew Jake aside as Fritsche and Harold hooked up electrical cords and moved a workbench outside。 〃Okay。〃 He cleared his throat 〃Over there on that little bench below those trees〃…he pointed at the side of a hill about a half mile away…〃is the radar。 Harold will run that。 That's the radar the navy loaned me。 Got it up there in an old two…holer that used to be here behind the tabernacle。〃 He stopped and showed Harold exactly how he wanted the power cables connected。
Jake joined him at a workbench。 〃Now this little radar suppressor…it picks up the ining signal on these three antennas here and feeds it into this puter over there。 Got four of the fastest chips made in this thing…Harold did most of the puter design。 puters are his bag。 Little hobby of mine too。 Anyway； the puter analyzes the ining signal： strength； frequency； direction； PRF…that's Pulse Repetition Frequency…and so forth； and generates a signal that goes out through these panion antennas to muffle out future signals。 That's why these antennas are twins。 You have a receiver and a transmitter。〃
〃But you can't suppress the first signal ing in？〃
〃Nope。 They get one free look。 The very first ining pulse will not be muffled。 Nor； in this generation of this device； will the second。 See； you can't get a pulse repetition frequency until you have received at least two pulses； which you must have to time your outgoing pulses； the muffling pulses。 But with existing radars； the return from one pulse will be treated like static。 The cathode…ray tubes need a lot more pulses than that。〃
〃And when the guy painting you stops transmitting； you beacon one more time？〃
〃That's the problem Harold and I are working on right now。 You see； after the first pulse es in； and the second； the puter then has to figure it all out and start transmitting。 Right now we've got the puting time down to about ten billionths of a second。 That's not enough of a clean chirp to let any existing radar get a definable return。 If the next pulse doesn't arrive right on time； we'll stop the muffling pulses ten nanoseconds later。 Just need to fix the software； the XY dipole and。。。〃 His voice fell to an incoherent mumble。
〃Why wouldn't a second radar that is in a receive…only mode see you beaconing to the first radar？〃
〃Bistatic radar？ It would；〃 said the genius in jeans； 〃if all we were doing was pulsing straight back at the transmitter。 But we aren't。 We're pulsing from a series of antennas all over the plane to neutralize the reflected signal。 Knowing how much to radiate； precisely enough yet not too much； that's where the puter really makes this thing work。 First you must know the exact reflective characteristics of the object you are trying to protect…that's your airplane…and put that data into the puter's memory。 Then the puter calculates the scatter characteristics of the ining signal and tells each of the two hundred transmitters positioned over the fuselage and wings and tail just how much to radiate。 All of the transmitters have to radiate in all directions。 And this whole thing has to work very； very quickly。 No puter was fast enough to handle this until superconductivity came along。 See； to make the electrical signals move along fast enough to make this work； I've had to super…cool my puter in a tank of liquid hydrogen and encase the wires to each of the antennas in this special sheathing。 That lowers the resistance just enough。〃 He gestured to a row of pressure bottles that stood in one corner of his workshop。 〃Still； there's so much puting involved we had to go to a distributed system with multiple CPUs。〃
Jake felt like a schoolboy who hadn't done his homework。 〃But how does the outgoing radar signal cancel the ining one？〃
Dodgers stepped over to a blackboard standing in the corner。 He looked around…〃Where's the rag？〃…then used his shirt sleeve to erase a spot 〃Harold； where's that blasted chalk？〃
〃Here； Dad。〃 The young man picked up a piece from a nearby bench。
Dr。 Dodgers drew a sine wave on the board。 〃Do you know anything about radiation？〃 he asked Jake gruffly。
Jake nodded hesitantly as he traced a sine wave in the air with his finger。 He knew from experience that claiming knowledge in the presence of a physicist was not a good idea。
〃It moves in waves；〃 Dodgers agreed dubiously。 He drew another sine wave over the first； yet the peaks of the second were where the valleys of the first one were； and vice versa。 〃The first tine is the reflected signal。 The second line is our outgoing signal。 They cancel each other。〃
Jake turned to Fritsche with raised eyebrows。 Fritsche nodded affirmatively。 〃This principle has been known for a century。 Dr。 Dodgers' real contribution…breakthrough…has been in the area of superconductivity at higher temperatures than anyone else has been able to achieve。 So he asked himself what puter applications were now possible that had been impossible before。〃
〃And came up with this one；〃 Jake muttered； for the first time seeing the intelligence and determination in that face under the bill of the cap。
〃Let's fire it up；〃 Dodgers suggested。 〃Helmut； if you will be good enough to take Captain Grafton and Harold up to the outhouse； I'll do the magic down here。〃
As Harold drove the rental car along a dirt track through a field； Jake asked； 〃How's security out here？〃
〃Security？〃 the young man said； his puzzlement showing。 〃The neighbors are all Presbyterians and Methodists and they think Dad's a harmless loony。 Their kids get curious and e around occasionally when they're out of school or in the evenings； but we don't tell them anything and they wander off after a while。 Just got to keep them away when we're radiating。 Been having some troubles with the power pany from time to time。 We sure pull a lot of juice when we're cooling down that hydrogen and they've dropped the load hereabouts a time or two。〃
〃We had the head of the Federal Power mission call the president of Pacific Gas and Electric；〃 Fritsche told Jake。
〃The district engineer still es around occasionally； though；〃 Harold continued。 〃I think he's harmless。 Dad's been feeding him a line about experimentation with electromagnetism； and he bought it 'cause he's local and knows Dad's a dingbat。〃 The youngster goosed the accelerator to take them through a mudhole in the road。 〃Nice car。 I'd sure like to have a car； but Dad…with the church and all。。。〃
The radar was mounted in the old outhouse on the bench where the seats once were。 It radiated right through the open door。 Harold Dodgers removed a padlock
