Hail Your Fiends with Auto SPEAKER (Jul, 1931)
Hail Your Fiends with Auto SPEAKER
TO BE able to hail your friends from your auto as you drive along the street, all you have to do is to install in your car a simple microphone arrangement consisting of a hand mike, an amplifier of the common two-stage type, and a speaker. With this novel stunt, you can merely speak into the mike and your voice will sound out loud and clear from the radiator of your machine, to the amazement of your friends who hear you.
The microphone can be of the regular button type, which can be purchased at any radio supply house. It is attached to the steering wheel, as illustrated in the accompanying drawing, to pick up your voice when you speak. The amplifier and “B” batteries—two 45 volt blocks—should be installed under the dash, where it will be easily accessible in case of trouble. The speaker will be most effective when supported under the hood, as near the radiator as possible, by means of a small platform or a length of pipe strap.
The hook-up is given in the accompanying wiring diagram. The hand mike should be hooked to the input terminals of the amplifier by means of a flexible cord, and the speaker to the output post9 with No. 14 rubber covered wire. It’s a wise idea to suspend the amplifier on springs to eliminate troublesome noises and to prevent damage to the tubes.
A two stage amplifier of the type used on antiquated radio receivers will be suitable as an amplifier for this auto speaker. You can easily obtain an amplifier of this type by scouting around some radio shop which handles second hand radio equipment.