| CHINESEWALL | Mountain ridges east and west, wholly a communications barrier |
| OLIVET | Mountain ridge east of Jerusalem |
| FIASCO | Motor-racing and horse-racing venue combined? Not wholly a failure (6) |
| OLIVES | Mount of ___ , sacred site and limestone ridge east of the Old City of Jerusalem (6) |
| CHINE | From "pin, thorn", word for a beast's vertebral column; a cut/chop of this for cooking; otherwise, an angle in a ship's hull, a crest of land, a deep Dorset ravine, a mountain ridge, a projecting rim |
| SPINES | Evergreens behind small mountain ridges (6) |
| ARETES | Sharp mountain ridges, especially in the Alps (6) |
| MAPS | Navigation aid containing a mountain ridge's passes (4) |
| POSTALCODE | A communications innovation first used in the UK in Norwich (1959) and Croydon (1967) |
| SAMUELMORSE | US inventor of the first electric telegraph and a communications code which bears his name (6,5) |
| MORSE | Samuel ---, American inventor of the first electric telegraph and a communications code which bears his name (5) |
| SPUN | Did a communications director's job |
| HEDYLAMARR | Glamour girl who invented a communications system during WWII |
| HEARSTSFIRSTS | Historic events at a communications company? |
| ATT | Part of a communications company's 800-number |
| TELEGRAPHOFFICE | 1900-built heritage site in Whitehorse that was a communications hub: 2 wds. |
| TELEPRINTER | Machine which transmits hard copy via a communications line (11) |
| ITT | U.S. manufacturer founded as a communications co. in 1920 |
| COMCET | Tradename for a communications satellite (6) |
| COMSAT | Tradename for a communications satellite (6) |
