[Milsurplus] 618S1/ARC-38 Servos

[Ray Fantini]

Thanks to everyone who has responded with comments on the servo dilemma. I am seeing output from the discriminators but still do not have any good servo action, also an additional item of information. When you change channels on the radio a relay (K-802) interrupts the input to the chopper feeding the servo amplifier that tunes the IF rack, this relay inserts a DC control voltage developed by a switch and resistor network on the back of the IF deck that forces the servo to center the tuning rack, this is not working either, the relay engages when you select a new frequency but the rack dose not center. This would leave me to think the problem is in the servo system or switching network or some other part that is beyond my meager understanding. My new idea is to take a spare ARC-38 chassis I have and install only a relay, servo and IF assembly with all covers removed and get that to work. So now I will be building up a mock up bench for working on obsolete servo systems, If and when I get this working will have to post MPEG of its operation on the web site.
Ray Fantini KA3EKH