The best plan is to mount each of the coils upon a tripod and experiment by placing them close together at first and gradually moving them apart until the maximum distance that the apparatus will work is discovered.
Be very careful to keep the two coils exactly parallel.
Much depends upon the battery. Be certain that it is capable of delivering a good strong current. Do not hold the key down any longer than is absolutely necessary, or the telephone transmitter will become hot.
By making the coils six feet in diameter and placing from 200 to 400 turns of wire in each coil you can make a set which is capable of transmitting speech 300 feet or more.
Fig. 241.—A Complete Wireless Telephone and Telegraph Station for Amateurs. 1. The Telephone Coil. 2. The Telephone Transmitter. 3. Double-Contact Strap-Key. 4. The Battery. 5. Spark Coil. 6. Key. 7. Spark-Gap. 8. Aerial Switch. 9. Loose Coupler. 10. Detector, 11. Fixed Condenser. 12. Code Chart. 13. Amateur License. 14. Aerial. 15. Telephone Receivers.
The coil may be mounted on the wall of your shop in a position where it will be parallel to one located in your chum’s house.
The success of a wireless telephone system of this sort lies in making the coils of large diameter and many turns, in keeping the coils parallel, using a sensitive transmitter and receiver, and in employing a good strong battery. Storage cells are the best for the purpose.
