| Field | Radio-electronics |
| Went Obsolete | 1980s |
| Made Obsolete By | Popularity of FM radio |
| Knowledge Assumed | Able to listen for a strong signal |
| When useful | Still used in adjusting the AM portion of most AM/FM radios and any other time a loop antenna is used such as for radio direction finding. |
To adjust the antenna you must actually turn the radio unless the antenna is an external loop. The signal will be strongest in two directions as both ends (90 degree rotation from where the wires are) of the antenna have gain. Once the antenna is adjusted for maximum loudness, you may turn the antenna or radio 180 degrees to position it better to hear the speaker, adjust the controls ect.
