[Sten]

Hi,

I called S-Tec Friday afternoon and talked with Scott Howard. Can’t say he was over enthusiastic about the idea to modify my 50-system that came out of a C172, to fit the 337. Also said installation had to be done by a S-Tec dealer. I told him we have our own maintenance shop, and if it can be done, the 50 will be installed here with or without their support.

Anyway, after a lengthy discussion he explained their part # system. He also faxed a parts list for the 337 S-Tec 50-System.

The computer is fairly easy to modify, it’s just a matter of “replacing a few resistors”. The servos are different, as there is a specific servo speed for each aircraft. It has to be the right servo, and they are “very expensive” to modify!

The gyros are all the same except for the turn coordinator voltage, and the lamp voltages if so equipped.

For most Skymasters, the Computer part # is 0132-0-7, Roll Servo # 0106-R9, and Pitch Servo # 0108-P4. These are the numbers for a 28 volt system. The 14 volt part # ‘s change only the first four digits, the dash # of the computer and servos remain.

So, I’m still as confused as ever! Seems also to be some different opinions about the excellence of the original 400 System!

Next, I will have a look at the dash numbers of the 50 System I have. And try to locate a manual of the 400 System in the aircraft, so I can construct a test device to check the servos.

If the 400 servos are OK, I’ll probably try to find a good computer for the existing system. If not, and the dash numbers are right, it will be a winter project to install the 50-System!

Comments appreciated!

/Sten