When may a public coast station authorized to use high frequency narrow-band direct-printing (NB-DP) establish contact with a ship station using telegraphy?

• A. Never. Contact may only be established using NB-DP circuits
• B. When the ship is in excess of 300 gross tons
• C. When the radio station license reflects authority for this type of operation and harmful interference is avoided
• D. When it is known that the vessel does not have a selective ringing or calling device

Answer: (C)

A public coast station authorized to use high frequency narrow-band direct-printing (NB-DP) can establish contact with a ship station using telegraphy when the radio station license explicitly allows for this type of operation and it is ensured that harmful interference is avoided. The conditions for using NB-DP, along with telegraphy, stem from regulatory requirements intended to minimize interference and promote efficient communication practices in maritime operations.

The license reflects the authorized modes of operation, including any specific stipulations on combining modes like telegraphy and NB-DP. This emphasis on the license is crucial because it ensures that all operations comply with the governing regulations established by the FCC, which is responsible for managing frequencies and ensuring they are used appropriately without causing harmful interference to other stations. Therefore, having the proper licensing to conduct these communications and taking steps to avoid interference are key components that validate the operation's legality and effectiveness.