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- I-PASS Electronic Toll Pass Transponder, circa 2006 - This electronic collection device reduced collection time on Illinois toll roads. Drivers mounted the device on the interior of an automobile windshield. The device sent out an electronic signal to the toll plaza and the toll was deducted from the driver's prepaid account as they cruised through the gates. Devices like this were introduced in the 1990s.
- circa 2006
- Collections - Artifact
I-PASS Electronic Toll Pass Transponder, circa 2006
This electronic collection device reduced collection time on Illinois toll roads. Drivers mounted the device on the interior of an automobile windshield. The device sent out an electronic signal to the toll plaza and the toll was deducted from the driver's prepaid account as they cruised through the gates. Devices like this were introduced in the 1990s.
- Aircraft Position Transponder, 1924-1929 - A transponder uses radio signals to identify the position, call sign, and altitude of aircraft. When the pilot pressed a button on this unit, it sent a radio signal called a "squawk code" down to ground controllers. This early transponder was used for a commercial route--its buttons are marked with several Indiana cities and signals for bad weather.
- 1924-1929
- Collections - Artifact
Aircraft Position Transponder, 1924-1929
A transponder uses radio signals to identify the position, call sign, and altitude of aircraft. When the pilot pressed a button on this unit, it sent a radio signal called a "squawk code" down to ground controllers. This early transponder was used for a commercial route--its buttons are marked with several Indiana cities and signals for bad weather.