Autopatch
A radio feature for accessing telephone networks via DTMF tones.
An autopatch, also known as a phone patch, is a function found in amateur radio repeaters, two-way radios, or base stations that enables an outgoing telephone connection. To use it, an operator needs a transceiver that can generate DTMF (touch-tone) signals. The autopatch module is usually configured to restrict calls to flat-rate numbers, such as local calls or toll-free lines.
The practice of linking an amateur radio station to the telephone network dates back to the early days of amateur radio and was also used commercially—for example, with the Carterfone device, which led to lawsuits from the telephone companies involved. The term "phone patch" more accurately describes a system where a user manually operates a base station to dial and connect to the telephone network, a method common before computer automation became widespread. This differs from mobile telephony, which began with the AMPS cellular network, first using a car phone as the terminal, and later with the DynaTAC, the first handheld mobile phone.
Radio amateurs primarily use autopatch to provide emergency telephone service in areas where the regular telephone network is unavailable. An amateur operator with a vehicle-mounted transceiver can offer telephone access from dozens of miles away, depending on the repeater or base station's frequency, the transceiver's power, band conditions, and antenna gain at both ends. In the United States, Federal Communications Commission regulations prohibit music on amateur radio frequencies, so autopatch users must disconnect if they encounter music on hold.
- Alternative name
- phone patch
- Required user equipment
- transceiver capable of producing DTMF signals
- Typical call restriction
- flat-rate numbers (local calls or toll-free numbers)
- Primary use
- emergency telephone connectivity to places that have lost telephone network access
- Us fcc restriction
- users must hang up if they encounter music on hold
Lore & Background
The practice of connecting an amateur radio station to a telephone network existed from the beginning of amateur radio, and was used commercially as well, as was the case with Carterfone, prompting lawsuits filed by the companies to which it was connected. The term phone patch more accurately describes a system that is dialed and connected to the telephone network by a user manually operating an amateur radio base station, which was more common before computer technology made automation of the process easier. This is contrasted with mobile telephony, which began with the arrival of the cellular network AMPS, initially using a car phone as the cellular terminal, and finally with the arrival of the DynaTAC, the first mobile phone 'properly talking' (being able to hold the whole unit in the hand).
Reader's Guide
The autopatch is notable for its role in providing emergency telephone connectivity to areas that have lost telephone network access. An amateur radio operator with a transceiver installed in their vehicle may provide telephone network access from dozens of miles away, depending on the frequencies of the involved repeater or base station, the power of the transceiver, band conditions, and the gain of the antennas on both ends. In the United States, autopatch users are required to hang up if they encounter music on hold, as the Federal Communications Commission regulations prohibit music on amateur radio frequencies. The feature's legacy is tied to the broader history of connecting radio to telephone networks, including commercial use that led to legal challenges, as seen with the Carterfone device. The distinction between an autopatch and manual phone patch highlights the shift from manual operator intervention to automated computer-controlled systems.
Did You Know?
- An autopatch is sometimes called a phone patch.
- Users must produce DTMF signals to make a call via an autopatch.
- In the United States, autopatch users must hang up if they encounter music on hold due to FCC regulations.
- The practice of connecting amateur radio to telephone networks existed from the beginning of amateur radio.
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