Transponder Set Test Set TS-4077/APM-424, which is a part of Transponder Set Test Set AN/APM-

424(V)2, is a small hand-held, preflight test set. It provides complete flight line and shipboard checkout of all AIMS transponder systems. Transponder Set Test Set TS-4OJl/APM-424, along with the other items listed in table l-l, are housed in the transit case during shipment and storage. Brief descriptions of the items supplied are contained in the following paragraphs. 1-2. Test Set. The test set can perform complete testing of IFF transponder systems. The test set CPU automatically adapts test set transmitted power level and receiver sensitivity to transmit-path losses between the test set and transponder antenna. This capability enables a"

operator to get accurate test results from many positions relative to the transponder antenna. Thus, many different kinds of systems may be accurately tested under varying conditions of operator location and distance. The test set is powered by a battery stick or six commercial C-size nickel-cadmium batteries. The test set is operated using push buttons and test results are displayed optically through the viewfinder. An automatic self-test sequence is performed each time an interrogation is initiated. I" the event a self-test fault occurs, an F will be displayed in the lower right corner of the display. A condensed operating instruction decal Is affixed on the test set antenna for easy reference. The test set complies with EM1 requirements of MIL-T-28800 as specified In SA-ALC/MfIIREC-PD-393D. NOTE No other type of batteries can be used in the test set except those described above. l-3. Transit Case. The transit case provides physical and environmental protection for the test set and accessories during storage and shipment. l-4. Computer Interface Cable. The computer interface cable Is used during Mode 4 programming to provide interconnection between the test set and  nterrogator Computer KIR-lA/TSEC. The computer interface cable can accommodate either 117 Vat, 60 Hz, or 28 Vdc operation for the KIR-lA/TSEC. 1-5. Battery Stick. The battery stick Is the dc power source for the test set and consists of six nickel-cadmium C-size rechargeable battery cells. The six battery cells are welded together to form a single battery stick 11.3 inches long which provides 7.2 Vdc power. l-6. Spare Battery Stick. For convenience, a spare battery stick is supplied. 1-J. End Cap. The end cap is used to make ground connection from the battery stick to test set or battery charger chassis. The end cap also secures the battery stick In place. 1-8. Standard Battery End Cap and Standard Battery Contact Assembly. A standard battery end cap and standard battery contact assembly are provided to adapt the test set to the use of six standard C-size nickel-cadmium rechargeable battery cells.