Category Archives: Radio history

1920: Radio Communications With Mars?

1920Jan28WashTimesThis 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.

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.

Portrait of William H. G. Bullard.jpg

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.”



1970 Hallicrafters Ad

Screen Shot 2019-12-17 at 12.17.48 PMFifty 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.

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Service Radio School, Washington, 1920

1920Jan25WashTimesIf 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.



1950 Two-Tube Two-Band “Progressive” Receiver

1950JanPM1950JanPM2This 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.

1950JanPMschematic



Are Engineers People? 1930.

1930JanRadioBCWe 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.



1960 Homemade Computer

1960EI2Sixty years ago, the gentleman shown here was undoubtedly the first one on his block to own a personal computer, since he built this one, as shown in the January 1960 issue of Electronics Illustrated.

The device was essentially a binary counter. The pulses from the telephone dial went to a series of six flip-flop circuits, and the total was shown in binary with the top row of lights. So to add, you just dial in the numbers you want to add, and then read the sum (in binary) on the lights.

Subtraction was also possible, since subtraction of a number was the equivalent of addition of the number’s complement. In this case, since the computer handles 6 digit binary numbers, it can display 0-63. Thus, the complement of a number is 64 minus that number.  The bottom row of lights showed the complement of the number shown in the top row.  (For example, the complement of 110000 is 001111.)

Multiplication was possible by repeatedly adding, and division amounted to repeatedly adding and seeing how many times the addition was necessary.

The author does conclude by noting that the computer was intended as a demonstration model. Accordingly, it had little practical use “unless the builder takes the time to study some of the readily available literature on computer techniques and mathematics. I do not recommend that anyone not familiar with high school mathematics attempt to construct it, as it will merely become a toy of limited value.”



Postwar VHF Allocations

Screen Shot 2020-01-15 at 1.19.09 PMAs you can see, there were still a few tweaks to be made, such as the elimination of TV channel 1, and the exact limits of the FM broadcast band.  But by January 1945, the postwar allocations for the VHF and UHF spectrum were pretty much in place.  This chart appeared in the January 1945 issue of Radio Service Dealer.



1960 Squelch for Benton Harbor Lunchbox

1960JanElectronicsWorldSixty years ago this month, the January 1960 issue of Electronics World carried a simple modification for the venerable Benton Harbor Lunchbox, in this case, the Model CB-1 CB transceiver.

James Green, the Chief Engineer of WELO, Tupelo, MS. The station had purchased two of the sets for communicating with one of the station’s engineers “living in a rural area devoid of telephone services.” For that reason, the set was going to be in operation for 18 hours a day, and the constant rushing noise of the superregenerative receiver “simply could not be tolerated.”

Green came up with a simple solution to the problem. Contrary to what one might think, the voice peaks of a received signal are louder than the rushing sound. Therefore, he simply used a sensitive relay from the rectified output of the audio output transformer. Then, the volume was turned to just to the point where the voltage was too low to energize the relay coil. At that point, the relay switched the speaker out of the circuit. When a call came in, the voice peaks generated a higher voltage, and the speaker kicked in. A capacitor kept the relay engaged for a short time so that the relay wouldn’t chatter between words.

A switch bypassed the squelch, so that the volume could be turned up or down.

The remarkable thing about this article is that a rig as simple as the CB-1 was actually put to a business use. For those who malign CB, I’ve noticed that 11 meters is so quiet these days that it can probably be used for useful communications, just like it was 60 years ago. As shown below, CB rigs are dirt cheap, and an antenna can be made for next to nothing. For short-distance communications, they can be useful for many applications.



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Official BSA Radio Kits: 1960

1960JanBL

Sixty years ago, Scouts looking to put together their own radio receiver could head down to the local BSA authorized dealer and pick up one of these official BSA radio kits, as shown in the January 1960 issue of Boys’ Life magazine.

There were two sets for the standard broadcast band. A two-tube set for $11.95 had a built-in loudspeaker. For headphone use, the one-tube set sold for $7.25. Both reuquired batteries. The filaments on both sets ran off a 1.5 volt battery for 20 cents. The two-tube set’s 90 volt B battery sold for $3.95, and the one-tube set’s 22.5 volt battery sold for $1.50.

For Scouts who already had radio building experience, it was time to move up to the short waves. That set, which looks like a regenerative receiver with one or two tubes, sold for $15.95. It ran off standard household current, so no batteries were necessary. Headphones were an additional $2.95, and “3 extra coils,” presumably to tune the short waves, were $2 for a set.

There was also an official BSA crystal set sold complete for $2.95. We actually had one of these around the house when I was a kid, and the chassis for this set was the bottom of the cardboard box it came in.

Finally, for Scouts working on their code, the Official S-O-S Signal Set sold for $1.95 for a single unit, or $3.95 for two units. The mathematically astute will realize that you paid a nickel extra if you bought two, but that presumably included the wire to hook the two units together.

1960JanBL2This issue of the magazine also contained a reminder of the upcoming February Boys’ Life radio contest, and in anticipation, contained some SWL’ing pointers by none other than Tom Kneitel.  Kneitel’s article contained some tips for pulling in DX, and a listing of some of the loudest and most likely to be heard stations from 3.2 to 25 MHz.

1960JanBL3



1960 Kit Building Venue

1960JanEIThe hottest night spot in Greenwhich Village 60 years ago was a loft at 732 Broadway. A wide cross section of New Yorkers gathered there–school kids, attorneys, mailmen, a concert violinist, and a lady psychologist. For a dollar an hour, they had access to a workbench, tools, soldering irons, and test equipment where they could assemble electronic kits.

The workshop was the brainchild of Dave Muirhead and Elliot Gorden, described by the magazine as experienced audio men. In addition to the physical facilities, there was plenty of expert advice available as the customers put the finishing touches on their Heathkits, Knight Kits, and Eicos.

That address is currently the home of Universal Musical Instrument Co. From their Yelp reviews, I wouldn’t be surprised if there were a few old Heathkits buried under the musical instruments. According to one review, it’s a great place for those building or inventing their own musical instruments in search of affordable parts. “The proprietor often will let you browse, chaperoned, once he understands what you are there for.”

The profile shown above appeared in the January 1960 issue of Electronics Illustrated.