I bought this PE-101-C dynamotor through eBay in March of 2005, with plans to add it to my junk pile for potential use as a power supply for some future homebrew project. It appears to be unused WW-II surplus. It turned out to be interesting enough that I’d rather use it as part of a proper restoration of the radio system that it belonged to.
Here are its electrical ratings from the dataplate:
|Input||13/26 VDC 12.6/6.3 A|
|Output||400 VDC 0.135 A|
|Output||800 VDC 0.02 A|
|Output||9 VAC 80 Hz 1.12A 95% power factor|
Some exploration on the Internet revealed that this dynamotor belongs to an IFF (Identification, Friend or Foe) radio set called the SCR-515 by the Army, and the ABA by the Navy. One reference suggested that it belongs on a mount called the FT-255.
The connector housing has “SO-132” stamped on top, and easily opens for access to the wiring after removing a spring clip. Most of the screws are secured with safety wire.
At first, I thought that the mechanism on one end was a governor, and it appeared to be missing a cam to actuate the moving contact that is accessible through the small door on one end of the housing. I later learned that the mechanism is a gear reduction mechanism, and that the missing piece is a notched coding disk that could be changed in order to program the IFF response code.
Here are two sets of the disks that set the IFF response codes:
In these pictures I’m missing disk MC-341 and I have an extra MC-345 disk, but I’ve since corrected that problem. I do not yet know whether any other disk sets were made. I think these sets are really rare.
In December of 2005, I found a nice example of the transceiver that is the heart of this IFF set. Like the dynamotor, it looks like unused surplus. It’s even mounted on a plywood base with proper mounting studs; I suspect that’s part of the original packaging for shipment.
When installed, this transmitter would be equipped with explosive devices which would destroy the transceiver in the event of a crash. I believe that the destructors would screw into the threaded sockets on the bottom of the transceiver, which are strategically located to allow the destructors to destroy the most important parts of the unit. I’ve been told that the red cable would be connected to a shock sensor which would trigger the destructors in the event of a crash. I don’t know if there was also a provision to manually activate the destructors. I’ve read anecdotes that some of these units were surplussed out with the destructors in place.
I’m interested in finding all of the matching connectors and/or cables, mounts, documentation and other components needed to complete this IFF set.