Mar 242005
 

PE-101-C Dynamotor

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:

Manufacturer Wincharger Corp.
Type 41S1
Temp. Rise 40°C
RPM 4800
Duty Continuous
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.

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Here are two sets of the disks that set the IFF response codes:

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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.

BC-645-A Transceiver

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.

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I’m interested in finding all of the matching connectors and/or cables, mounts, documentation and other components needed to complete this IFF set.

 

  21 Responses to “SCR-515 (Army) or ABA (Navy) IFF Transceiver”

  1. PE-101-C dynamotor- I started working with these units in 1952 when I was in the 10th grade. There are three types , type 1 is the one you have (PE-101-C marked signal corps US Army order 1488 phila 42. Type 2 is (CWD-21AAX dynamotor keyer unit , Navy department-bureau of ships model ABA-1 . type 3 is the same as type 1, (marked signal corps) these have a larger door and a different keyer unit to make changing coding disks easier. All three types have the same input and output.

    Also for your information in 1952 the dynamotor sold for $2.88 and the radio
    set for $9.88 new in box.

    Wayne Beiswinger

  2. Would you consider selling one of the iff code disc sets, I have a pe 101 c dynamotor, and I have always been interested in seeing how it works. I have also worked with dynamotors since 1958, and my first older radio was a Hallicrafters s-38. i would very much appreciate any information you may have on these discs. Kindest regards, Jim Bryan.

    • I might have a third set which is not pictured here. It’s missing one wheel if I recall correctly. I’ll think about whether I’d like to sell it. Like James wrote below, eBay is one place to find this stuff, but it took several years for me to find the pieces that I have. I’m still missing pieces like control boxes that I’ll need to complete a set.

  3. I have only one set of code disc’s for my own use , also I have been asked about connecting plug’s and cables , again I do not have extra sets.
    Check E-bay for the code disc’s , and connecting plugs.
    wayne beiswinger

  4. There is not a lot of information on the code disc’s. Most of the connecting plug’s were made by monowatt , i am not sure if they made the cables.

    I have one of the original mounts for the dynamotor , it does not have any numbers or marking on it. There is a mount for the radio , I do not have one.

    There is also dual panic kill buttons for the radio , I have seen them , but I do not have any. Check E-bay for the disc’s , there were some on recently.

    wayne beiswinger

  5. I just want you to know how much I appreciate your consideration about the code discs, I very much would like to buy them regardless of the missing disc, kindest personal regards, James Bryan.

  6. HI, JUST WONDERED IF YOU WERE TRYING TO CONTACT ME REGARDING THE IFF CODE DISCS, SOMETIMES I DO NOT GET MY MESSAGES, THANK YOU, JIM. MY EMAIL IS JWBRYANJR@AOL.COM

  7. Just wondered if you found the IFF code discs you would consider selling to me, kindest regards, Jim Bryan.

  8. Yes, very much so, and thank you very much for your reply, I understand as Im behind in my piano lessons, kindest regards, Jim.

  9. Just wanted to wish you a Merry Christmas and a happy new year, kindest regards, Jim Bryan.

  10. HI,would you know where i might find a control box and plugs for the scr 515 set, thank you.