radio compass

The man he had been sent to track down by means of the radio-compass was coming south over the trail.

The man, so the radio-compass had said, had taken the trail which led straight away toward the Arctic Ocean.

Instantly his hands flew to the radio-compass as he muttered.

To catch a radiophone on wheels, Curlie had reasoned, one must mount his radio compass on wheels and pursue the offender.

He adjusted the coil of a radio-compass here, another there and still another here.