Telephone Hybrids - HY-03DTD
HY-03DTD Dial Tone Detect Add-On-Board.
HY-03DTD Dial Tone Detect Add-On-Board

The HY-03DTD is a dial tone detect add-on board for the HY-03 range of products. As standard, the HY-03 range can automatically disconnect the line once K-break is sensed. Using the HY-03DTD allows audtomatic disconnection in different countries based on the following table:
| Country or Equipment Type | Frequencies | Type | Details |
| Austria | 440Hz | Continuous | - |
| Avaya PBX | 400Hz | Cadence | 375ms on, 375ms pause |
| Belgium | 450Hz | Continuous | - |
| Bulgaria | 425Hz | Cadence | 250ms on, 750ms pause, 750ms on, 1000ms pause |
| Cyprus | 350Hz and 450Hz | Continuous | - |
| Czech Republic | 425Hz | Continuous | - |
| Denmark | 425Hz | Continuous | - |
| Finland | 425Hz | Continuous | - |
| France | 440Hz | Continuous | - |
| Germany | 425Hz | Continuous | - |
| Greece | 440Hz | Continuous | - |
| Hungary | 440Hz | Continuous | - |
| Iceland | 425Hz | Continuous | - |
| India | 400Hz | Cadence | 750ms on, 750ms pause |
| Ireland | 400Hz and 450Hz | Continuous | - |
| Israel | 400Hz | Continuous | - |
| Italy | 425Hz | Cadence | 200ms on, 200ms pause, 600ms on, 1000ms pause |
| Italy2 | 425Hz | Cadence | 200ms on, 200ms pause |
| Japan | 400Hz | Continuous | - |
| Luxembourg | 425Hz | Continuous | - |
| Netherlands | 450Hz | Continuous | - |
| Norway | 425Hz | Continuous | - |
| Poland | 425Hz | Continuous | - |
| Portugal | 425Hz | Continuous | - |
| South Korea | 350Hz and 440Hz | Continuous | - |
| Spain | 425Hz | Continuous | - |
| Sweden | 425Hz | Continuous | - |
| Switzerland | 425Hz | Continuous | - |
| Taiwan | 350Hz and 440Hz | Continuous | - |
| United Kingdom | 350Hz and 440Hz | Continuous & Cadence | 750ms on, 750ms pause |
| United States | 440Hz and 480Hz | Continuous | - |
