A hundred years ago this month, the January 1920 issue of Boys’ Life magazine carried this ad for a real telephone for real boys. The set came with two transmitters, two receivers, and 150 feet of wire, all for $2. The ad noted that for longer distances, bell wire could be used. The set was available from dealers, or directly from the Robbins Manufacturing Company, 1807 N. Central Park Avenue, Chicago. It was billed as just the thing for scout work.
Seventy-five years ago this month, the January 1945 issue of Popular Science showed this simple tester for troubleshooting radio circuits if problems “can’t be located by guesswork”. The top portion was an audio or radio-frequency circuit tracer. You worked backwards from the speaker to locate the source of the trouble. The bottom section was a continuity tester. If you heard a click in the headphones, then you knew there was continuity. To test a capacitor, you would connect it and hear a click. If you waited a few seconds and repeated the process, a weaker click would tell you that the capacitor was holding its charge.
I didn’t use them, but the radio does have a number of preset memories. I simply used the up-and-down tuning and didn’t bother with the memories.
The Need for a Cheap Receiver
I purchased it from Walmart because I needed it quickly and didn’t have time to order online. My pastor will be traveling to Africa to visit a remote congregation with which we partner. Our denomination also helps sponsor an FM radio station in the closest city. I do not know whether it is possible to receive the signal at “our” church in the remote village. Therefore, I wanted her to do a test to see if it’s possible. If she is able to receive even a weak signal, then it will be an easy matter to send some solar radios and perhaps an external antenna so that they can listen on a regular basis.
Therefore, I had to quickly find a suitable radio that I could send with her. And despite all of the radios I have lying around the house, I didn’t have exactly the right thing. It needed to meet the following criteria:
I found the GPX R300S at WalMart for about $8. It met the first three criteria, and I hoped against hope that it would meet the fourth. It was in stock at the local WalMart store, so I ordered online and picked it up at the store about an hour later while doing some other shopping.
Surprisingly Good on Both AM and FM
I was pleasantly surprised to discover that this is an extremely good tuner on both AM and FM. I only had time to play with it for a few minutes, but it did pull in all of the local FM stations, even weak ones, with no difficulty. If any commercial receiver is going to pull in the station we want to hear, then this one probably will. If it gets absolutely nothing, then I’m satisfied that a more expensive receiver won’t, at least without a high antenna.
It wasn’t necessary for this particular experiment, but I was also astonished at how good an AM receiver this set is. Unfortunately, in most cheap radios these days, the AM receiver is tossed in as an afterthought (if it’s included at all), and is only able to pick up the strongest local stations. I did the test at night, and was astonished to see that the radio was pulling in something on almost every 10 kHz channel. I was able to positively ID WSM Nashville and KFAB Omaha from my Minnesota location. Those stations are obviously powerhouses, but in my experience, most cheap AM receivers these days are not able to pull them in. The internal AM antenna was very directional, and I was able to easily null out signals by turning the radio.
Selectivity was also remarkably good for such an inexpensive set. Local 50 kilowatt blowtorch WCCO is on 830 kHz, and on many cheap radios spills over onto the adjacent channel. But I was able to hear another station faintly on 840, with no sign of interference from WCCO.
Has 100 kHz Tuning Steps on FM, But Only 10 kHz Steps on AM
The station we want to hear in Africa is on FM, so the AM performance wasn’t necessary for my test. But it was amazing how well it worked on that band. Unfortunately, the radio tunes only in 10 kHz steps, covering the AM band in the Americas, where all stations’ frequencies end in zero. Unfortunately, in the Eastern Hemisphere, stations are 9 kHz apart. Some frequencies are used in common, e.g., 540, 630, 720, etc. And some stations will be off by only 1 kHz, e.g., 549, 621, 639, etc. But some stations will be off by as much as 5 kHz, e.g., 585, 675, etc., and will be very difficult to tune. This is one case where an analog tuner would be better. I suspect it’s probably possible to modify this receiver to tune in 9 kHz steps. After all, they probably sell a similar version elsewhere in the world. But the instruction manual didn’t hint at any method of doing this.
The station we need to tune in happens to be on a frequency that is also used in the Americas. In other words, it’s on an “odd” frequency following the 200 kHz separation band plan, namely 96.7. Therefore, any North American receiver would have worked. This radio, however, does tune in 100 kHz steps and includes the “even” frequencies, such as 96.8, that are also used in the Eastern Hemisphere. Therefore, it will be able to tune in all local stations.
Usefulness in Rural Africa
I told my pastor to leave the radio as a gift with someone in Africa, since there’s no good reason for the set to make a round trip. If it’s not useful in the village where our partner congregation is located, it will certainly be useful in the city, where there are a number of FM stations, and she’ll have an opportunity to leave it there. The AM stations are more distant, and hopefully the radio will be able to pull at least some of them in at night. I noticed one of them in the nation’s capital was on a frequency ending in zero, so it least it will be able to pick up that one at night. The radio also contains an alarm clock, and I set it to the Eastern Africa time zone.
Unfortunately, it won’t be of much use after the batteries run out. It uses two AAA cells. It’s unlikely that those are available in the village. They almost certainly are available in the city, but I’m not sure at what price. I included two extra sets of batteries, which I assume will allow it to work for a few months of listening an hour or two a day. A solar radio would be much more suitable, and if we send any in the future, that’s what I will use.
Bottom Line
Most of the online reviews are favorable, but a few are not. So it’s possible that quality control is not the greatest, and that some units do not perform as well as mine. But for the low price, it’s certainly worth the risk. For the price, the GPX model R300S Portable Armband Radio is a very solid performer. If you need a cheap radio that still pulls in both AM and FM stations well, this radio is what you need.
Note: Some links on this page are affiliate links, meaning that this site earns a small commission if you make a purchase after clicking on the link.
This article appeared in the Washington Times a hundred years ago today, January 28, 1920. For a more recent summary of what the Martians would be able to hear, see our earlier post.
Mars May Be Signaling Us On Our Radios, Scientists
Here Agree With Marconi
Two Washington scientists in interviews today agreed with Marconi, the Italian who perfected wireless communication, that if Mars is inhabited there is a possibility of Martians attempting to get into communication with the earth.
May Get Our Messages.
James Harris Rogers at his laboratory. Wikipedia photo.
With the scientific world today engaged In discussions of Marconl’s suggestions of signals from Mars, causing “interruptions” to our earthly radios, Dr. James Harris Rogers, inventor of the underseas and underground wireless, whose laboratory is at Hyattsvllle. Md. and Admiral W.H.G. Bullard, in charge of the Naval Communication Service at Potomac Park, declared it their opinion that If Mars is inhabited it is possible that the Martians are getting our messages and may be trying to signal us.
“If Mars is really inhabited,” said Dr. Rogers, “it being so much older than the earth, there is reason to suppose the Martians are far more advanced that the inhabitants of the earth.
Waves Obey Laws of Light.
“I believe in the theory of the propagation of electro-magnetic waves, and that these waves obey all the laws of light, and that this energy thrown off from an aerial passes through the upper layers of atmosphere and is propagated in straight lines toward the other planets. So, if Mars is inhabited and the Martians have highly developed wireless receivers, it is within range of the possibility they are receiving signals or messages from the earth.
“Many scientists believe in what is known as the Heaviside theory; that is, that the upper regions of the atmosphere is so thoroughly ironized by the violate rays of the sun that it acts like a vast concave mirror, and that electro-magnetic waves sent from aerials do not pass through, or penetrate through, this layer, but are reflected back to the earth. This theory would preclude the possibilities of us talking or receiving messages from Mars.
“I do not believe in this theory.
No Satisfactory Explanation
“Marconi has state he has observed ‘strays’ at regular intervals–certain signals which possibly emanated from Mars. In my experience, in ‘listening in’ for many years, and studying all kinds of disturbances, I never have observed any regularity or anything to indicate that these signals were sent by intelligence.
“Scientists, however, have not found a satisfactory explanation for these ‘strays.” Of course some of them are attributable to atmospheric electrical conditions–such as from lightning, clouds charged with electricity. But the scientific world cannot today explain these ‘strays’ so satisfaction.
“I do not attempt to state that these ‘signals’ or ‘strays’ noted by Marconi are not emanating from the other planets. Great study and records should be kept of these ‘signals,’ as it were, to cause reasonable assuredness that they come from another planet.
“The ‘strays’ have not been of a single character. But, this could be explained that possibly senders from Mars, or some other planet, are using all sorts of characters in attempts to communicate with the Earth.
“But, if there are powerful transmitting instruments in Mars, going on the theory that the planet is inhabited, there is no reason why we cannot ‘receive’ their message here. Light received on this planet is nothing more than electro-magnetic waves, and the same applies to the transmission of wireless messages.
Earth’s Surface A Conductor.
“Due to the fact that the surface of the earth is a conductor, atmospheric conditions and disturbances such as lightning, or ‘strays’ which are caused at times by reaction between different layers of rarified air at extreme altitudes, do not penetrate through the earth’s surface to any extent and thus, by the use of underground wires, radio signals are received to the exclusion of a great amount of these disturbances.
“It may be further explained that the surface of the earth has a shielding effect on the underground wires and thereby prevents to a great extent the action of atmospheric disturbances on the system. Under no conditions when using underground system has a receiving operator been compelled to discontinue receiving because of nearby electrical storms, as aerial operators have been.”
Lets Visitor Hear “Strays.”
Dr. Rogers demonstrated the ‘signals’ and ‘strays’ that are received through his wireless apparatus. The visitor was permitted to “listen in” to a message being sent from the Navy to Lyons, France. The “strays” or what Marconi calls “signals from another planet,” were distinctly heard at frequent intervals.
“I have no doubt, if Mars is inhabited, that with the use of powerful receiving instruments it will not be long before we will be in communication with the planet. It may not be in my time, but it will come. But, I am not prepared to say that these ‘strays’ are signals from another planet. They will have to be further investigated. And, I will not say they are not signals from Mars. That’s just the situation. Time will tell, but it is not a thing of the impossible that if Mars or other planets are inhabited the earth will be in wireless communication with them some day.”
Investigating Phenomena.
Admiral Bullard. Wikipedia image.
The wireless phenomena, to which Marconi called public attention, are being investigated by Admiral Bullard and his associates. He is not ready to make positive statement of belife that Mars is trying to get in touch with this planet, but he sees no reason why this should not be a possibility.
“I will not say that Mars is trying to communicate by wireless with us,” said Admiral Bullard, “and I cannot say that the Martians are not. For years scientists have been studying these phenomena, and I do not give up hope that they will be made plain. We have no reliable data today how far the earth’s ether is disturbed when you set up one of the atmospheric oscillations by means of which we not communicate throughout the world-wide field. The whole business of radio communication has advance at an astounding rate of speed.
Experts Not Surprised.
“This generation may get into touch with the other worlds. Realizing that with the recent discovery that communication can be made by radio through a water surface–that our seaplanes can talk as freely with our submarines as you can talk with the suburbs–what are the possibilities of the radio communication?
“Many persons may laugh at the idea, but those in close contact every day with the world wonders of radio transmission are not greatly surpised at what may happen. I may not be able to call or talk to the Martians, but the man who takes my place may see this possible wonder of radio trasmittion.
A Ridiculed Washingtonian
“I see no limit to radio inventions. I do not fear ridicule, but I will not set a limit to the possibilities of man’s many inventions. A Washington dentist, long before Marconi was born, perfected a good system of air transmission. I understand he was laughed out of Congress when he asked for an appropriation of $50,000 to help him perfect the invention.
“As a matter of fact, however, we do not really know whether Mars is inhabited. If it is, all depends upon the intervening spaces, about which we now know nothing. The essence and composition of these air spaces, or whatever they may be called, may absolutely negative the idea of word or sound transmission. However, these air spaces may be of a favorable nature and make it possible for interplanetary intercourse.”
Sees No Code Difficulty.
Admiral Bullard said if Mars be inhabited and wireless or radio communication with the Martians be possible, he did not believe there would be any great difficulty over arranging a code. “Anything can be deciphered today,” he said.
“The final destination of the world’s shock oscillations is known to no one,” he said, “particularly the sound waves sent out from the earth today. I am not prepared to say what would happen if they should reach Mars. But, who can tell? We did not know only a few years ago how far radio messages could be carried, nor foresee its marvelous development up to the present time. No, I will not say it is not possible that the world communication with Mars by radio.”
Fifty years ago this month, the January 1970 issue of Popular Electronics carried this Hallicrafters ad for the company’s solid state Model S-120A Star Quest receiver, which covered the broadcast band through 30 MHz.
An earlier AC-DC tube version, the S-120 had been sold a few years earlier, but this one was solid state, and could run off household current or 12 volts. The ad identifies Hallicrafters as a subsidiary of Northrop Corporation, and it’s likely this was one of the last pieces of radio gear sold under the Hallicrafters name.
My guess from the picture is that dad bought the receiver for his son for Christmas, but it doesn’t look like Junior is getting a chance to use it, as dad discovered the fun of SWLing. But Junior could have made the best of the situation by putting together the simple three transistor regenerative receiver shown elsewhere in the magazine.
A century ago, these children didn’t have to worry about their friend going home and taking the ball. The ball was supplied to children by their San Francisco playground. The only rule was that children could take the ball as far as they liked.
The picture appeared a hundred years ago today in the Philadelphia Evening Public Ledger, January 26, 1920.
If you wanted to earn a big salary and see the world a hundred years ago, one way of going about it was to become a radio operator. And one place where you could learn how to do that was just seven blocks away from the White House, at the Service Radio School, 900-2 Pennsylvania Ave. N.W., Washington. Day and night classes, as well as correspondence classes, were available. Average daily attendance at the school was 400, from nearly every state in the Union.
This ad for the school appeared a hundred years ago today, in the January 25, 1920, issue of the Washington TImes.
This duo are putting the finishing touches on a two-band, two-tube receiver, as shown 70 years ago this month in the January 1950 issue of Popular Mechanics. The set tuned the broadcast band and 1.5-15 MHz shortwave with plug-in coils. The set as shown here used a 6SG7 as RF amplifier, with a 6SN7GT detector and AF amplifier.
The chassis looks a little bit empty because this is a “progressive” set. The version shown in this magazine would start pulling in the stations, using headphones. Later issues of the magazine would show improvements. An external power supply is used, but at this point, only the filament winding of the power transformer is used. The article cautions to carefully tape the high voltage leads, as they wouldn’t be used until a later version. In the meantime, the filaments are run from the power supply, with batteries supplying the B+ voltage.
The article noted that hand-wound coils were requested by builders of earlier versions of the set, and they were obliged with complete coil winding instructions.
We have many engineers in our readership, and they will undoubtedly be interested in the answer to this question, namely, “are engineers people?”
The question is posed in an ad by Sylvania tubes from the January 1930 issue of Radio Broadcast magazine.
Unfortunately, they ad doesn’t give a straightforward answer to the question. We agree, however, that one ought to be a suspecting person, a doubter. The company provided a coupon to write for more information, but you first had to affirm that yours was an open mind.
