96 



METHO'DS OF COMMUNICATION FOR FOREST PROTECTION 



Pig-. 48 Lookout station telephone set installed in the field 



Section 76 Howler and Condenser for Vibratory Signalling 



The signals from the 1004- A portable telephone set are received at the stations 

 by means of a howler (Fig. 82). Every station which it is desired to call directly 

 with a portable set of this type must be equipped with a howler, but in most cases 

 it will be found satisfactory to equip thus only the more important stations and 

 call others by first signalling those with howlers and having them raise the desired 

 station in the usual way by bell signals. The howler must be bridged between line 

 and ground through a 1-microfarad condenser, except on very short lines with light 

 loads when it may be bridged between line and ground direct. The most convenient 

 method of wiring the howler connection is to bridge between the line and ground 

 posts of the protector in the case of a grounded line (Fig. 5'Q) and between the two 

 line posts of a metallic line. 



The two binding-post? on the howler will generally be found marked L and G. 

 In making the installation run an insulated wire from the line side of the protector 

 to one post of the condenser. From the other condenser terminal run a wire to the 

 L post of the howler and then connect the G post of the latter to the ground or 

 G terminal on the protector as shown in Fig 50. Do not reverse these connections 

 on the howler as this will reduce the signalling capacity. 



Howlers should all be adjusted after being permanently installed. They should 

 never be touched, except for the purpose of adjustment, after they are once located 

 and adjusted. 



