Now bring a pair of No. 12 or 14 insulated wires from the 110 volt lighting leads and connect them with a single-throw, double-pole switch; connect one pole of the switch with one of the posts of the primary coil of the alternating power transformer and connect the other post of the latter with one of the posts of your key, and the other post of this with the other pole of the switch.

You can buy a double-pole, double-throw switch mounted on a porcelain base for about 75 cents and this will serve for Set No. 1. Screw this switch on your table between the sending and receiving sets and then connect one of the middle posts of it with the ground wire and the other middle post with the lightning switch which connects with the aerial.

For this experimental continuous wave telegraph transmitter get the following pieces of apparatus: one single coil tuner with three clips; one .002 mfd. fixed condenser; three .001 mfd. condensers; one adjustable grid leak; one hot-wire ammeter; one buzzer; one dry cell; one telegraph key; one 100 volt plate vacuum tube amplifier; one 6 volt storage battery; one rheostat; one oscillation choke coil; one panel cut-out with a single-throw, double-pole switch, and a pair of fuse sockets on it.

Now bring a pair of No. 12 or 14 insulated wires from the 110 volt lighting leads and connect them with a single-throw, double-pole switch; connect one pole of the switch with one of the posts of the primary coil of the alternating power transformer and connect the other post of the latter with one of the posts of your key, and the other post of this with the other pole of the switch.

For this experimental continuous wave telegraph transmitter get the following pieces of apparatus: one single coil tuner with three clips; one .002 mfd. fixed condenser; three .001 mfd. condensers; one adjustable grid leak; one hot-wire ammeter; one buzzer; one dry cell; one telegraph key; one 100 volt plate vacuum tube amplifier; one 6 volt storage battery; one rheostat; one oscillation choke coil; one panel cut-out with a single-throw, double-pole switch, and a pair of fuse sockets on it.

It consists of a pair of plug cutouts and a single-throw, double-pole switch mounted on a porcelain base as shown at K. In some localities it is necessary to place these in an iron box to conform to the requirements of the fire underwriters. Connecting Up the Transmitting Apparatus. The way the various pieces of apparatus are connected together is shown in the wiring diagram.

It consists of a pair of plug cutouts and a single-throw, double-pole switch mounted on a porcelain base as shown at K. In some localities it is necessary to place these in an iron box to conform to the requirements of the fire underwriters. Connecting Up the Transmitting Apparatus. The way the various pieces of apparatus are connected together is shown in the wiring diagram.

You can buy a double-pole, double-throw switch mounted on a porcelain base for about 75 cents and this will serve for Set No. 1. Screw this switch on your table between the sending and receiving sets and then connect one of the middle posts of it with the ground wire and the other middle post with the lightning switch which connects with the aerial.

Get two honeycomb or other coils of the greatest wave length you want to receive, for in order to properly balance the aerial, or primary oscillation circuit, and the closed, or secondary oscillation circuit, you have to tune them to the same wave length; two .001 mfd. variable condensers, though fixed condensers will do, and two small single-throw double-pole knife switches mounted on porcelain bases.

Get two honeycomb or other coils of the greatest wave length you want to receive, for in order to properly balance the aerial, or primary oscillation circuit, and the closed, or secondary oscillation circuit, you have to tune them to the same wave length; two .001 mfd. variable condensers, though fixed condensers will do, and two small single-throw double-pole knife switches mounted on porcelain bases.