Triplett Signal Corps Test Set I-56-J

General Notes

The test set is a boxed set comprising the 1183-SC combination tester which tests valves and includes both built in multimeter functions and separate multimeter type 666-SC and AF output meter type 650-SC. It was made for the US Army Signal Corps in 1943 under Order 27101-PHILA-43.

The 1183-SC is an emission type tube tester with sockets for most WWII US military receiving types and settings cards are provided covering most patterns. It comes with an extension cable with octal plug termination that can be plugged into a radio socket, using the supplied adaptors as necessary, with the valve itself in the tester. This allows voltage and current measurements to be made with the tube in service using the built in multimeter functions. It is similar in many ways to the University TVT and TST testers described on this site. The unit requires an external 110v supply for tube testing but the multimeter functions can operate independently with internal batteries for resistance checking.

The complete unit is quite heavy - I would estimate around 25kg.

Collectability

The whole I-56-J set up is quite impressive but not the sort of thing that looks good on a shelf, especially when packed in its case. The 1183-SC could be a useful tester on its own, but lack of sockets and data for post war or European valves is a drawback. These units would be very rare in Australia and even in the US there is little about them on the web, though the 1183-SC on its own gets a few mentions. The 110 volt power is a drawback in Australia. Probably of little interest to collectors unless they have plenty of space.

Condition

The example I had looked quite impressive and had some of the accessories, including the manual and adaptors. The power and octal leads had been cut, possibly in the interests of safety and there were no meter leads. All these could be replaced, but there are other faults that would make it difficult to restore to full operation without access to orignal spare parts. The case and all its components have serial number 2894.

I have now disposed of my unit therefore cannot provide any more information than is on this site.

Further pictures of this unit can be seen on my picture gallery.

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Page maintained by Simon Buxton VK2UA . Created: 8/04/06 Updated: 20/08/2007