Fifty years ago, this British family stayed connected thanks to this three-transistor (one germanium, two silicon) intercom, from the May 1973 issue of Everyday Electronics. The set was tested with a range of fifty feet, and the author believed that it would perform well over a much longer connection. Similar commercial units were available, but the cost of materials (about three pounds) of this project was considerably lower.
The master unit used a spring-loaded push to talk switch.
Seventy-five years ago this month, the March 1947 issue of Boys’ Life offered scouts some predictions about what wireless communications might look like in the future. The words “handi-talkie” and “walkie-talkie” had entered the lexicon, thanks to military use of portable transceivers, and the magazine predicted that civilians would soon be enjoying their widespread use.
It starts by noting how a radio-equipped newspaper reporter could easily scoop the other papers, but the equipment was getting lighter, smaller, cheaper, and simpler, and the magazine predicted that use would be widespread.
The FCC had already authorized the citizens’ radio service on UHF, and the magazine noted that the FCC had allocated a full “10,000 kilocycles” of spectrum to the service.
The magazine hinted that a link to the telephone network wasn’t far off, and you would soon be able to “make, or receive, phone calls from your family car as you drive along.” You could even call another car!
The magazine did get some things right:
As the things come into common use, there will be a field day for cartoonists and gag writers. All kinds of funny new situations will arise when all of us begin to walk around, carrying on phone conversations as we go.
But, funny or not, the day is bound to come. As someone once remarked, ‘the world do move.’
And they got one more thing mostly right:
Taking one hand off the wheel might constitute a traffic hazard, so there is room for improvement in the equipment. Perhaps our engineers will soon be able to give us a radio telephone that works like a radio microphone and loud speaker. Then the motorist would be able to carry on his conversation simply by touching a button with his left foot, leaving both hands on the wheel. Automatic transmissions are foot eliminating clutches anyway, so the driver’s left foot will be free to take on a new job beside that of just dimming the lights.
I remember as a kid seeing a structure similar to this one. I don’t remember exactly where, but it was somewhere along the route between Minneapolis and Duluth, with one horn facing south, and the other facing north. I asked my parents what it was, and they said it was for relaying TV signals. It made perfect sense to me, since the two horns looked a lot like TV screens.
I didn’t know what was inside, but now I do. The electronics were on the top floor, the B+ power supply was on the third floor, the filament power supply was on the second floor, and a backup generator was on the ground floor.
This diagram appeared 70 years ago this month in the February 1952 issue of Radio-Electronics. Click on the image to see the full size version.
Telephone answering machines didn’t really become a thing until the 1970s, and even then, they were expensive and rare. At first, even their legality was dubious, since The Phone Company was jealous of anyone making any kind of direct electrical connection to the Public Switched Telephone Network. I didn’t have an answering machine myself until well into the 1980s. Surprisingly, there was a time when the phone just kept ringing when nobody was home, and there was no way to leave a message. Similarly, if your phone rang, the only way to find out who was calling was to pick up the phone and talk to them.
For those who were unwilling to wait for the future, the February 1962 issue of Popular Science showed you how to put together your own answering machine. And since there was no direct connection to the phone line, you didn’t have to worry about provoking the ire of The Phone Company. When the phone rang, an inductive coil placed under the phone would sense it, and it would trigger a solenoid which would physically lift the button on the phone. It would also turn on the tape recorder, which had been left in the “play” position. The tape recorder would then play your outgoing message through the speaker, which was close to the telephone handset. At the end of the outgoing message on the tape, you had painted silver paint on the back of the tape. When this passed through an outboard sensor you had added to the recorder, it would trip a second solenoid, which would flip the switch on the tape recorder from “play” to “record”. The microphone was placed next to the receiver, and it would record for thirty seconds. At the end of this thirty-second piece of tape, there was another section of silver paint, which would reset the whole contraption for the next call.
You would need to prepare the tape in advance for as many calls as you expected to get, including multiple outgoing messages and silver paint sections.
For the outgoing message, you were instructed to tell the caller to leave their 30 second message when they heard the “click.” Presumably, the sound of the tape recorder switching over from playback to record would be sufficiently loud to serve as the cue.
To hear your messages, you would first glance at the tape to see if it had been used. If so, you would need to first remove the tape from the external switch, since running the tape through it unnecessarily would quickly remove the silver paint. You would then plug the tape recorder directly into the wall, rewind, and listen to the tape, which would include both your outgoing messages and the incoming messages.
As you can see from the schematic below, the control circuit used tubes, to switch the relays and solenoids. Since one of the relays was used to turn the tape recorder on and off, the tape recorder itself would need to be a solid state model, since there would not be time for the tubes to warm up.
After it was built, the device had to be adjusted. In particular, there was a sensitivity control for the circuit triggered by the ringer. In order to adjust it, the phone had to be ringing. And, of course, the only way to do that was to call someone else and ask them to call you.
A hundred years ago this month, the January 1922 issue of Popular Mechanics carried the curious tale of sixteen-year-old Willetta Huggins. She had been both deaf and blind for three years, but she was able to “hear” by placing her finger on the diaphragm of a telephone receiver. “With this discovery she soon learned that she could conduct a telephone conversation almost as well as any normal child of her age.”
The magazine recounted a demonstration in which she successfully received a message by wireless telephone, witnessed by a number of dignitaries including Wisconsin Governor John J. Blaine. For whatever it was worth, the magazine noted that the message had been sent on 800 meters (375 kHz), and received with an audion detector and 50 foot antenna.
She also reportedly had the ability to discern colors by smell. In one experiment recounted by the magazine, she was able to identify the colors of six samples of yarn, simply by smell. She was also able to identify the color of the Governor’s suit by smelling it.
But this isn’t the end of the story. According to the New York Times, she was pronounced cured in 1924, and regained her vision and hearing. She ascribed her cure to her Christian Science beliefs, and attested that she had been “completely and permanently healed.” Reportedly, as of 1970, she had changed her name and was working as a Christian Science healer in a midwestern city.
There was a time, not so long ago, when an absolutely necessary skill for any kind of orator was the ability to project one’s voice. Entire books were written on the subject, such as this one that notes:
Bear in mind that as voice is dependent upon a copious supply of air, under the control of the will, so breathing is dependent upon pure blood, which, in turn owes its existence to proper and sufficent food and physical exercise.
Whenever you read a speech that predates electronic amplification, whether it is the Gettysburg Address or Teddy Roosevelt’s “Big Stick” speech, it is well to remember that if those in the crowd heard what the speaker was saying, it was only because they were able to hear the voice. This began to change in the 1930s and 1940s. For example, we previously reported, the legislative chambers of the Iowa State Capitol were first wired for sound in 1939. Before that date, the legislators had to project their voices so that they could be heard throughout the chamber.
And a member of the clergy had to have something besides a grasp of theology, Greek, and Hebrew. He had to have a strong enough voice. Eighty years ago this month, the October 1941 issue of Radio Retailing put it this way:
Many an earnest young divinity student was advised to leave the ministry because his voice was not considered strong enough.
But the magazine also noted that “today, this condition no longer applied,” and it presented an opportunity for the entrepreneur able to supply the requisite sound system.
The magazine carried the case study of Harbison Chapel at Grove City College, Pennsylvania, which was brought into the twentieth century by F.C. Millard’s Modern Sound Systems of Pittsburgh.
The Gothic chapel could seat 900 and was long, narrow, and tall. Millard was able to provide a satisfactory system at a cost of $632.80 (according to this inflation calculator, almost $12,000 in 2021 dollars), plus installation and wiring. The system consisted of two Western Electric 633A “saltsharker” microphones, one each at the pulpit and lectern, a 12-20 watt 124D amplifier, and a single horn speaker above the pulpit. A mixer was installed at the rear of the balcony.
The college’s president, Dr. Weir C. Ketler, noted that the system functioned so smoothly that the congregation could hear well yet be scarcely conscious that amplification was in use.
Today, if you want to contact someone who is traveling, it’s a simple matter of dialing their cell phone number. Wherever they are in the country, or even the world, their phone will ring, and you will be speaking with them. You can text that same number, or e-mail them, and you can be reasonably certain that you will contact them. And you don’t need to know where they are.
This is a new phenomenon, and it hasn’t always been this way. As recently as 30 years ago, if you wanted to contact someone, then you needed to know where they were.
Things began to change with the advent of cellular phones in the early 1990s, but only if the person had a cellular phone, which wasn’t always the case. And you had to know their phone number. For many users, the number was a closely guarded secret. They had to pay per minute for all calls–incoming and outgoing–so they didn’t give the number to just anyone. (Some countries solved this problem by having callers pay, but in the United States, almost without exception, the cellular subscriber had to pay for the airtime.)
But at first, even if you had the number, there was no way to call someone outside of their home area, without knowing where they were. In short, if you were on the road, you might be able to make outgoing calls, but you wouldn’t be able to receive incoming calls.
This 1990 news article made a prediction, which seemed almost unbelievable at the time:
Currently, callers seeking someone who has traveled away from his or her local calling area must know where that person is in order to complete a call. With automatic call delivery, a person “roaming” outside the home market will send out a locating signal to the closest cellular system whenever he or she turns on the cellular phone. Computers then will do the searching and service authorizations.
“If you’re up in Chicago and I’m back in Washington and all I’ve got is your local Washington number, I’m going to be able to dial that Washington number . . . and that phone call is going to find you . . . anywhere in the United States,” said Norman Black, a spokesman for the cellular phone association.
That was almost unbelievable, but according to the article, it was going to happen by 1992. It did eventually happen, but for most customers, it took a bit longer.
Prior to the 1990s, there was really no way to contact someone who was traveling, unless they called you. In emergency situations, broadcast stations might fill in. Occasionally, on stations such as WCCO Minneapolis, it wasn’t uncommon to hear a message such as the following:
The Minnesota Highway Patrol has asked our assistance in locating John Doe of Minneapolis for an emergency message. John Doe of Minneapolis, please call the Minnesota Highway Patrol for an emergency message.
When I heard those, I always wondered what kind of tragedy befell that particular family. But presumably, they heard their name on the radio, called the Highway Patrol, and were put in touch with whoever had the bad news for them.
In 1973, an idea came along that was ahead of its time–a method to contact travelers anywhere in the country. Messages could be sent to anyone anywhere in the country, as long as the traveler was willing to stop at a popular roadside retailer. It was really an early version of e-mail, and certainly one of the first methods of digital communication that most Americans had ever seen.
The store was equipped with a computer console with a CRT screen and 10 digit numeric keyboard. Before you left on your trip, you would tell the folks back home that they could always reach you by calling the Stuckey’s HELPS line in Georgia. From early in the morning to late at night, a friendly operator would answer the phone. After hours, there was answering machine. The caller would tell the operator that they had a message for you, and give the operator your home phone number (or other agreed-upon number). The message would be a phone number that you were to call back.
When you stopped for gas at any of the 350 Stuckey’s locations, you would go inside and use the free terminal. It would prompt you to enter your phone number. The terminal would link back to Stuckey’s headquarters via Western Union lines, and would display any messages, or tell you that you had none. If you had a message, then you would go to the payphone and call them. You would have to pay for a long distance call, but you only had to pay for one long distance call.
The beauty of this system was that the caller didn’t need to know where you were. As long as you bought your gas at Stuckey’s, it didn’t matter if you were in Maine or California–you would get the message.
The system got the approval of the New York Times:
Stuckey’s deserves a large bouquet of pralines and a rousing round of applause from the motoring public for having invented a free, public service with no strings attached that is probably the greatest contribution to the motorist’s peace of mind since the free gas company roadmap and the hopefully clean gas station rest room.
The console had a second function. The store manager had a key that converted it into a terminal for ordering stock from the company’s warehouse. The annual cost of the system was estimated at $660,000.
As a youngster, I remember seeing one of these machines and thinking to myself what a good idea it was. Of course, I entered our home phone number, and there were no messages for us. As far as I know, it didn’t last long, and I never saw another one of the terminals. It was a very good idea, but perhaps a bit ahead of its time.
A hundred years ago, if you were located 26 miles across the sea (40 kilometers, for those in leaky old boats) at Avalon, Santa Catalina Island, California, you could enjoy the luxury of telephone service with any telephone in the United States, thanks to the radiotelephone service operated by Pacific Telefone and Telegraph Co., as described in the March 1921 issue of Radio News.
The system consisted of stations KUVX at Avalon and KUXT at Long Beach. A complicating factor was the presence of naval station NZL, also located at Avalon. To avoid interference, the radiotelephone receiving station employed a wave trap to null out NZL’s frequency. The article gives the radiotelephone wavelength of 425 meters (706 kHz). The system was full duplex, meaning that there would be different transmitting and receiving frequencies. Since the 425 meter wavelength is discussed in conjunction with the wave trap on the receiving antenna, it appears that the Long Beach station transmitted on 425 meters, and Avalon transmitted on a different frequency.
The author described an interesting catch for an SWL as part of a test conducted by the Avalon station. He listened in on a conversation from Avalon to the mainland, which was carried by the transcontinental telephone lines to New York, where the call was carried by another radiotelephone station to a ship in the Atlantic. The author reported that the voice was a little distorted, but could be clearly heard throughout the ten minute test.
The Avalon station was powered by a motor generator, and to avoid having to restart the power, the carrier was left on 14 hours a day, with calls to and from local hotels, stores, and residents carried as needed. A licensed radio operator oversaw the transmitter, connected to an eight-wire antenna, and receiver, connected to a loop antenna. A telephone operator put through the calls, presumably with another operator at the Long Beach side of the circuit doing the same.
The system was able to transmit telegraph signals simultaneously with telephone conversations without interference. This was accomplished by “superimposing a high pitched harmonic on the carrier wave.”
A more detailed technical description of the system can be found in the December 1921 Proceedings of the IEEE. You can also find additional references at Wikipedia, which notes that the system was replaced by a submarine cable in 1923, ending the possibility of radio listeners being able to tune in to telephone conversations.
Sixty years ago this month, this stenographer dutifully takes down a verbatim transcript of her boss’s telephone conversation, thanks to a Lafayette telephone amplifier. The amp is connected to the phone through a telephone pickup coil, still readily available today. With it plugged into the amp, she can easily hear both sides of the conversation.
The unit was actually a kit. While it is not specified, we suspect that the secretary put it together herself, since it freed her of the need to use a headphone for such tasks, and probably made her work much easier.
The photo appeared in the December 1960 issue of Popular Mechanics, which highlighted a number of available kits, and pointed out how many, such as this one, could make things run more smoothly at the office.
It looks like Bell Labs was working on this idea toward the end of the war, and it probably wasn’t implemented, at least on a very large scale. But this ad from the September 1945 issue of Popular Mechanics sounds like a good idea for quickly laying lines for military field telephones. Instead of having men do the work on the ground, possibly through enemy territory, an airplane does the job, at a rate of 16 miles in 6 – 2/3 minutes. One end, with a weight and parachute, is dropped to the ground. Then, wire is spooled out continuously.
