由于搞SDR需要找对比对象,就下狠心从美帝搞了台R-390A回来。买SSD009也是需要进行对比才购进的。
初步测试R-390A的灵敏度比SSD009高了10分贝不止。我这个R-390A是1962年制造,到今年整50年了,
开机工作一切正常。但是考虑到年代久远,各个频点晶振、滤波通道,BFO振荡器需要进行维护校正了,所以准备
按照美帝原来的手册进行校正维护,这是一个比较慢长复杂的过程,美帝的手册上有些提到的设备我也没有,所以按照
自己的理解使用其他仪器进行测试。
这个帖子可能会根据我这台机器的实际情况发展跳过R-390A手册上一些校准步骤,也可能多出来一些自身发挥的东西。
我希望我这台R-390A能够在SDR研发过程结束前进入工作状态,以便进行对比测试。
http://www.r-390a.net/
是维护资料的来源网站
单独的接收机或发射机比收发一体机相对来说好修就是通道单向的简单易懂。
校准按照美帝的手册第六章开始了
6.1 Introduction
6.1.1
This Chapter provides alignment and repair procedures to enable maintenance personnel to correct deficiencies found as a result of scheduled maintenance and troubleshooting procedures in Chapter 4 and 5 respectively. Before any alignment is attempted all faulty components should be located and replaced. A definite need for alignment should be established by accomplishing sensitivity and bandwidth tests (paragraphs 4.3.1 and 4.3.2) after eliminating faulty components.
6.1.2
The alignment section describes the recommended method by which the equipment is set up, test equipment is connected and used, and necessary adjustments are made to ensure proper equipment performance
6.1.3
The repair section outlines the methods necessary for disassembly, cleaning, repairing, and reassembly required to replace a faulty component within the receiver.
6.2 Alignment and Adjustment Procedures
6.2.1 General Alignment Information
se a fluted no. 8 Bristol wrench for adjusting the antenna, the RF, and the variable IF cores. Use the same tool for adjusting the tuning shafts during mechanical synchronization. Use a nonmetallic screwdriver for adjusting the various trimmer capacitors. Use a hexagonal, nonmetallic tool for adjusting the cores in T501, T502, T503, and Z503 on the IF subchassis. Be sure that this tool is inserted through the top core into the bottom core, and that the bottom core turns without disturbing the setting of the top core. Make this type of adjustment only after the particular coil or transformer has been replaced.
6.2.2 Test Equipment and Special Tools
1. RF Signal Generator AN/URM-25
2. Impedance Adapter MX-1487/U
3. Electronic Multimeter AN/USM-116
4. Multimeter AN/PSM-4
6.2.3 Test Conditions
1. Temperature: Normal room or shelter.
2. Humidity: Normal room or shelter.
3. Line Voltage and Frequency: 115 or 230 volts ac ± 1 percent at 60 Hz.
使用合适的电源(电源电压的调整请看相关电源单元的连接方法,解决110V与220V的转换问题)
4. Warm-up Period: At least 15 minutes.
预热15分钟以上
5. Standard Modulation: 30 percent AM at 400 Hz.
[ 此帖被BD1CM在2012-11-23 18:48重新编辑 ]