Richardson's handbook of projection (1930)

MANAGERS AND PROJECTIONISTS 1377 NOTE. — In event some acceptable substitute be used for replacement, always remember it is only a temporary makeshift. Secure a proper duplicate replacement part and install it as soon as possible. Not much can be done in case any of the transformers go bad, with one possible exception, namely in the case of a grounded transformer. This can possibly be remedied by insulating the transformer from the panel and removing the transformer ground wire, if one there be. Little need be said concerning the 43A amplifier, as its hook-up is very like that of the 42A, the chief difference being in the values of the voltages and currents. All the parts are built to withstand the higher voltages. Actual troubles and their remedying are the same as those set forth in dealing with the 42 amplifier. In case the 43 amplifier goes dead, the leads may be removed from the output terminals of the 42 amplifier, and the two others attached in their place and run up to the 200A panel. The leads going from the 43 to the 200A should be removed, of course. When the equipment consists of two forty-threes, and one of them goes dead, remove the leads from the dead 43 and put the leads from the remaining 43 on the 500 ohm output terminals of the 42. Many believe the 41 or the 42 amplifier may be cut out, but this is not true. Should the 42 go dead the plate supply for the 41 is gone also, even if a source of plate voltage were at hand, the power output of the 41 is so limited that it would be nearly useless, insofar as putting signals directly into the horns be concerned. The 42 or the 42 and a 43 cannot be used alone because that would leave only one, or at most two stages