Figure 1. An AZ moter cover to protect the motor.
Kashima Space Research Center
Communications Research Laboratory
893-1 Hirai, Kashima, Ibaraki 314-0012, Japan
The Kashima 34-m parabolic antenna can receive 1.5, 2, 5, 8, and 22 GHz bands. Now we are equipping it with a 43 GHz band receiver. The antenna was built in March 1988 and has recently become too old to work properly. So we are currently taking steps to restore it. In order to prevent corrosion of the antenna specific direction due to geographical conditions, we regularly change the stow position of the antenna AZ (Azimuth) . As the radio wave reflection paint on the subreflector gets corroded, we are treating the damaged surface. Maintenance is frequently done to prevent the top of the AZ rail from corroding. And to make it suitable for the Japanese environment. We installed an AZ and EL (Elevation) motor cover to protect the motor (Figure 1) and we also waterproofed the AZ rail cover (Figure 2). Maintenance is difficult when a cover is used to protect the rail and wheel. So in order to make maintenance easier, we made a rail cover opening (Figure 3) and a transparent wheel cover (Figure 4). Other minor but serious problems are as follows. The receiver power was turned off occasionally when the receiver control PC hang-up. The azimuth encoder shows slight different value from the real angle after the antenna turns 360 degrees in azimuth which in the future may obstruct high-frequency observations. These problems are currently being checked on.
