KB2AH
The two dishes you are looking at are located at FN20xc, the owner is KB2AH. Dishes have a F/D ratio of 0.43. A few of the details of these dishes might be a little amazing.
The big dish in the foreground is 10.3 meters. It is constructed completely out of steel. Ribs are made of .750 pipe and .375 solid steel. Dish rings are also .375 steel. Covering is galvanized wire mesh. Calculated weight of dish along is 4000 lbs. Counter weights 2000 lbs, support structure 1000 lbs.
The dish in the background is 6 meters. Ribs are stainless steel. Dish ring placement is every 6". Weight with mount is 3000 lbs.
On both dishes, the ribs were fabricated then were welded onto the hub. The 10.3m dish was built on its mount in the air. The 6m dish was built on the ground on its mount then raised to its position 6 meters above ground. Both dishes are fully walkable from rim to center. Both use chain and sprocket for azl, and hydraulic pistons for ele. SYSTEM STATS AZL's Consists of 30" dia. compass rose made on milling machine to 1 deg. increments. AZL is manually controlled and degrees are read by a video camera in shack ELE's Consists of a digital level good to 0.1 degree. Dishes are manually controlled, degrees are also read by a video camera in shack. Each dish has a camera with 75mm lenses, and are used when there is a visible moon. Six separate monitors are used.
Feed Horns are circular polarized. This enables the use of TX without a TX/RX relay. The feed has a return loss of -28db, isolation of -28db between TX/RX ports, and 1db circularity (see horn pic). LNA's are a cavity type, 0.2 db noise figure and 20db gain. The device used is a FHX35LG Hemt (see LNA pic). Feed lines are both 7/8 air.
Amplifiers are KB2AH ring amps. An output of 1.4KW is attained by using two 6-tube ring amps in parallel, combined with a 180-deg hybrid. The driver is a 1-tube cavity driving a 2-tube cavity driving the two 6-tube cavities. At full output there is a plate current of 3 amp at 1400 volts on the two 6-tube amplifiers. A total of sixteen 7289's are used in the system.
Tom Dinyovszky
Terrestrial Power Systems
405 Union Ln.
Brielle, NJ. 08730
Phone: 732-223-5067 (after 21:00 Z)
FAX: 732-223-0901
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E-mail: kb2ah@kb2ah.com
for info.
Created by Randy, W7HR
E-mail: hamradio@oz.net