| 1 | A | B | C | D |
| --- | --- | --- | --- | --- |
| 2 | Zweikanalton - How It Works |  |  |  |
| 3 | mode | existing OIRT 6.5 MHz or BG 5.5 MHz sound carrier contains: | 2nd OIRT 6.258 MHz or BG 5.742 MHz carrier contains: | pilot tone in 2nd carrier: |
| 4 | mono | mono | carrier is absent | none |
| 5 | stereo | mix of left & right (L+R) | right audio channel (R) | 54.6875 kHz 50% AM with 117.5 Hz |
| 6 | bilingual | 1st language | 2nd language | 54.6875 kHz 50% AM with 274.1 Hz |

Question: What does the second carrier contain?
Answer: The second carrier contains a 54.6875 kHz pilot tone for stereo or bilingual.