Awanui spark transmitter

The transmitter building comprised two rooms with a window between them: the “High Tension” Room housed the spark-gap transmitter, and the Operating Room housed the receiver, operating controls and switchboard. The transmitter power came from a 75hp Gardner engine in a separate building, the “Engine House”.

The HT (transmitter) room at Awanui. At the left are the keying

The HT (transmitter) room at Awanui. At the left are the keying “repeaters” (relays) mounted on a shelf below the large Earth switch. The step-up transformer is at the centre of the photo next to the window. The two cylindrical objects beside the transformer are probably RF choke coils. To the right of the photo are quenched spark gaps with their blowers mounted below them. Behind them is a bank of Leyden jars. Tuning inductors are suspended from the ceiling. Click to enlarge.

The Earth switch on the wall and keying relays on shelf below

The Earth switch on the wall and keying relays on shelf below, with blowers attached to the wall and feeding air via ducts to the relays. Photo: Awanui Scrapbook, Te Ahu Museum

In the photo above, blowers can be seen mounted on the wall below and to each side of the shelf holding the keying relays. Whether this was the original design or a later variation is unknown. In the next photo, there is a single blower, apparently sitting on a stool in front of the shelf. Other photos on this page show a blower attached to the front edge of the shelf.

Transmitter room at Awanui c1913. Earth switch on the wall at left, with keying relays on bench below (the blower looks like an after-thought). To the right are spark gaps and Leyden jars.

Transmitter room at Awanui c1913. Earth switch on the wall at left, with keying relays on shelf below. To the right are spark gaps and Leyden jars. The blower for the keying relays is sitting on a stool rather than wall-mounted as in the previous photos.

Leyden jars in foreground and tuning coils hanging from the ceiling. Through the window can be seen a portion of the switchboard in the operating room. The aerial switch is in the corner of the room, partially obscured by the tuning coils.

Leyden jars in foreground and tuning coils hanging from the ceiling. Through the window can be seen a portion of the switchboard in the operating room. The aerial switch is in the corner of the room, partially obscured by the tuning coils. Click to enlarge.

The aerial switch in the HT room, which was controlled by a lever in the operating room via a rod passing through the wall.

The aerial switch in the HT room, which was controlled by a lever in the operating room via a rod passing through the wall.

Close up of earth switch on the wall and keying relays on bench below

Close up of earth switch on the wall and keying relays on shelf below, with a blower attached to the shelf.

Another close up of earth switch on the wall and keying relays on bench below

Another close up of earth switch on the wall and keying relays on the shelf below, with a blower attached to the shelf.

"Generators" at Awanui Radio. No other details available.

These are described as “Generators” in the Awanui Scrapbook at Te Ahu Museum. No other details available