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The following photos are from SETI League and have been shown here accordingly to their Fair Use Policy


At the conclusion of the EuroSETI04 Science and Technology Workshop, executive director Dr. H. Paul Shuch (left), along with Russian regional coordinator Dr. Alexander Zaitsev, toured the Project Argus station of German regional coordinator Peter Wright. Though their respective governments had once told them they were enemies, contemporaries Paul and Sasha found themselves close colleagues and fast friends, thus reinforcing The SETI League's unified global perspective.
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Peter Wright points out part of the plethora of instruments and antennas that constitute the Mannheim Radio Telescope facility. Built by Peter and other members of the European Radio Astronomy Club, this facility is used for continuum radio astronomy, pulsar detection, Jupiter monitoring, meteor-scatter, high-energy pulse reception, solar observations, and, of course, SETI.
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"Yagis and dishes and loops, oh my!" Plus discones, collinear arrays, corner reflectors, horns, and even an X-ray detector tube for detecting the effects of gamma and cosmic rays, allow the Mannheim Radio Telescope to monitor a wide expanse of the electromagnetic spectrum.
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Sasha Zaitsev checks out the receiver cab, inside the box onto which the primary rotatable dish is mounted.
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Hinged arms allow feeds and electronics for various bands to be individually hoisted into the prime focus of the main 3-meter dish. Here Peter Wright has exposed the L-band feed assembly.
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Close-up of the opened L-band feed box, showing the low noise amplifiers, quadrature hybrid, downconverter, and below them the LNA cooling system.
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Microstripline side of the UEK-21 downconverter from SSB Electronic GmbH, which shifts the 1420 MHz hydrogen line region to the 28 MHz amateur band.
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The groundplane side of the SSB Electronic downconverter. Trimmer capacitors are used to adjust the resonant frequencies of the various tuned circuits. At left is the overtone crystal for the local oscillator/multiplier chain.
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Also inside the L-band feed box are two 1420 MHz SSB Electronic low noise amplifiers, one for each of two orthoginal linear feedhorn polarizations.
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Each LNA sports a pair of helical resonator filters, affording the preamplifiers with 6 MHz total bandwidth and good out-of-band signal rejection.
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A look inside one of the SSB Electronic SLN 1420 MHz low noise amplifiers reveals two GaAs FET stages, with microstrip interconnect and discrete inductive noise matching.
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Inside the L-band feed electronics box, Peter Wright brandishes a torque wrench to tighten up the SMA connectors.
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Sasha Zaitsev helps Peter Wright to attach the insulating foam cover to the L-band electronics assembly. Note the power, signal, ventilation and cooling connectors, coming through the bottom rear of the box. Semi-rigid coax lines can also be seen running from the two feedhorn probe connectors to the side of the box.
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Peter has now covered the L-band electronics box with reflective mylar, for thermal regulation.
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Next, a protective vinyl cover is placed over the complete feed box, and held in place with Velcro.
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Peter attaches thermally insulated coolant lines, running into the box from a refrigeration compressor within the equipment room. This system reduces the noise temperature of the overall receiver circuitry by several tens of Kelvins.
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On another hinged feed arm, a pneumatic actuator rotates one of two different feeds into position.
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With the piston in the retracted position, a C-band feedhorn and its associated electronics are selected...
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...while with the piston fully extended, a Ku-band feedhorn and receive system move into the focal point of the reflector.
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Peter shows an alignment pin, used to help in positioning any of several hinged feed arms precisely at the focal point of the prime focus dish.
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Said alignment pin being installed to a post extending from but secured to the dish hub.
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Sasha screws the alignment pin into position, while Peter directs the operation from safely on the ground. This is the same radio telescope from which Peter fell two weeks prior, injuring his Achilles tendon.
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Now Peter begins to swing the hinged C-Ku-band feed arm into position at the focal point of the three meter parabolic reflector.
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Having facilitated proper positioning of the C-band feedhorn, the alignmnet pin has done its job, and must now be removed.
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Motorized chain-driven elevation rotor system for the 3-meter dish. Elevation can be manually controlled via computer, or manually adjusted with a joystick.
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Here is the adjusting nut for controlling tension and backlash on the elevation rotor chain drive.
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Having lowered the C-Ku-band feed harm, Peter prepares to convert the telescope to L-band operation. He starts by attaching a hoist rope to an anchor point on the L-band arm.
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Next, he begins manually to raise the arm, while pulling on the other end of the rope.
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As Peter continues to pull on the rope, a pulley directs the force normal to the length of the arm, further raising it toward its ultimate position.
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A stop on the arm secures it against the surface of the dish when in proper position. The rope is then tied off with a boat cleat, until it is time to again lower this arm to change bands.
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Having powered up and cooled the L-band front-end electronics, Peter is now ready to get on with the business of discovering ETI.
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Some more pictures from the radio observatory in Mannheim

Dish Mannheim Front

Dish Mannheim Rear

Me & Dish

President's Lecture

Lecture
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