Hallicrafters HA-1, Operating And Service Instructions

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SECTION III
INSTALLATION
3-1. UNPACKING
After unpacking the Model HA-1 keying unit, examine it closely for any
possible damage which may have occurred during transit. Should any sign of
damage be apparent, file a claim immediately with the carrier stating the extent of
the damage. Carefully check all shipping labels and tags for any special
instructions before removing or destroying them. Remove all protective shipping
material around tubes and components.
3-2. LOCATION
The keyer should be placed in a location which permits free circulation of air
around the cabinet, particularly at the rear. Avoid excessively warm locations
such as those near radiators and heating vents.
The mercury-wetted relay employed requires that the keyer be operated in a
position no greater than 30° from a horizontal plane.
3-3. KEY LEVER
Various styles of commercially built key levers are available for use with
electronic keyers. Any of these are suitable for use with the Model HA-1 keying
unit. Connections to the key and panel jack are made as shown in figure 2. Key
lever connections are also provided at the control socket on the rear of the unit
(See paragraph 3-4-1-1).
Figure 2. Key Lever Cord for Front Panel Key Connection.
It can be noted by referring to the schematic diagram, figure 9, that the key
lever base is connected to chassis ground and the dot-dash contacts are operated
at an extremely low negative potential. This makes the key assembly completely
free from shock hazard.