How to Plan Your System
To save your time and steps when the telephone rings for someone else in your family who is some distance away, you can install a simple bell or buzzer system to summon that person.
First, you must plan what you are going to do. On a large sheet of paper, draw to scale (roughly) a plan of your house and grounds, including those places where phones are located. It will help if you rule off your paper in 1/8" or 1/4" squares and let each square equal one foot. Show the location of poles supporting your wiring.
Next, pick out those areas where you or others would likely be when someone else would answer the phone and want to call you to it.
After you have thought about this, and talked it over with members of your family, show locations on your plan where you think you would like to have buzzers or bells, and show a button beside each telephone. (Generally, you should have a bell or buzzer near each phone, also.)
Figure 3 shows diagrams of various types of systems, and will help you determine the number of wires you will have to install to connect the buttons and bells that you have planned.
Inside, you will connect your transformer and the various buttons and bells with ordinary indoor bell wire. Outdoors, however, you should use weatherproof 2-wire or 3-wire telephone twist.
Show on your plan the distances that must be traversed by each type of wire, and show the number of conductors in each. Don't overlook the vertical distances (one floor to another).
Figure 3