1967 Homemade Electronic Bug

1967JanEI

Fifty years ago this month, the January 1968 issue of Electronics Illustrated offered just the thing for aspiring spooks, namely, this homemade electronic bug. Housed in the ubiquitous cigarette pack, the tiny device transmitted on the AM band, and could be picked up 10-50 feet away.

It was billed as suitable for listening in on “your neighbor, close friend, worst enemy, bookie, business partner, the business competition, or even you.”

As shown here, the parts had a price tag of about $20, although the article noted that the price might be lower if slightly larger components would be acceptable.

The circuit used four Motorola transistors, three 2N4123’s and one MPS3646 handling the RF output duties. It was constructed on a circuit board with holes drilled for the components, with wiring on the other side.

The battery shown here is a Burgess H-177 9.8 volt battery, although the article pointed out that a standard 9 volt battery could be used if the slightly larger size were acceptable.



1918 Ground Current Telegraph

1918JanPS1With civilian radio (both transmitting and receiving) shut down for the duration of the war, hams a hundred years ago still had a desire to engage in communications. As we’ve seen prevsiously (here, here, here and here), one method of communicating without the use of radio waves is a ground-conduction telegraph. And a hundred years ago this month, the January 1918 issue of Popular Science showed how to do it.

The magazine noted that “because the Government, for good and sufficient reasons, has put a ban on amateur wireless stations, it does not follow that all your activities must stop.” It noted that communicating by ground wireless was “almost as interesting” as actual radio and was “permitted by the Government, since high tension apparatus need not be used, at least not in their normal capacities.”

While the magazine noted that the Allies were apparently not using this type of communication, “for all we know the Germans may be using it now,” and that it had a potential range of forty miles, and perhaps more through salt water.  (The 40 mile estimate seems extremely optimistic, but I can’t say I’ve ever tried it.)

1918JanPS2In addition to the basic circuit shown above, the magazine also showed this more advanced setup, which permitted full break-in operation (with the addition of a normally-closed contact to the key).  It looks just slightly dangerous, and would probably trip a modern ground fault interrupter.  It doesn’t appear to send any signal over the power lines, but does use the electric service ground as one of the two connections.



Blaupunkt Palma 2435 (1957)

1957BlapShown here is Gerti Daub, Miss Germany 1957, along with two other avid SWL’s, tuning in a program on their Blaupunkt Palma 2435 receiver.

The seven-tube set retailed for 390 Deutschmarks, and tuned both the longwave and mediumwave broadcast bands, FM (up to 100 MHz), and  shortwave.  You can see the set in action at this video:

 

 



My First Radio Receiver by V. Borisov

SovietMyFirstRadioThe young comrades shown here are constructing their first radio receiver, according to plans contained in the 1955 Soviet book, Мой первый радиоприёмник (My First Radio Receiver), by V. Borisov , part of the series Библиотека юного конструктора (Library of the young designer), a series of small books published between 1937 and 1964 showing various construction projects, many related to radio.

SovietMyFirstRadioCrystalSet1The first set in the book, shown here, is not immediately recognizable, but it is a simple crystal set, with a tuning range of 200 to 2000 meters (150 – 1500 kHz), to cover the longwave and mediumwave broadcast bands.

The largest component is the dual coil, which appears to be a manufactured part.  The two binding posts on the left are for the antenna (A) and ground (3).  The knob in the center is a switch for selecting taps on the coil.  The actual detector is not shown.  It plugs into the terminals at the top right of the top drawing.  The headphones plug in to the other set of terminals.

The detector, shown below is a manufacture fixed detector.

SovietMyFirstRadioDetector

The book’s second crystal set, shown below, is slightly more advanced, and is shown below.  This set also uses the same fixed crystal, and includes a variometer, which also appears to be a manufactured unit that the builder purchases.

SovietMyFirstRadioCrystalSet2

The final crystal set is shown below.  It uses the same fixed detector, and includes a variable capacitor for tuning.  The fixed coil in this one appears to be much simpler than the ones employed in the other set, but there don’t appear to be any instructions for winding it.  So I assume that this is also an item that the builder simply purchases.

SovietMyFirstRadioCrystalSet3

SovietMyFirstRadioTubeSetAfter showing these crystal set designs, the book moves on to some simple vacuum tube receivers.  The basic one-tube receiver is shown at left.  Since I can’t read much of the text, it’s a little unclear exactly which circuit is shown here.  The text includes a number of different schematics, along with different pictorial diagrams for the tube socket.  I assume this is because different builders might get their hands on different tubes, and the diagrams are shown for various common tube types.  A representative example is shown below, the circuit diagram for use with a 1Б1П tube.

SovietMyFirstRadio1b1pSince B batteries might be hard to come by for struggling soviet radio builders, the book also includes plans for a power supply, using a transformer and 5Ц4С dual rectifier (the equivalent of a Western 5Z4G).

The book also contains plans (but unfortunately, no picture of the completed set) for a two-tube regenerative receiver with one stage of audio amplification to drive the speaker.  This set is presented after the rather complex power supply is shown, so I assume it’s a project for the advanced student.

The book shows how to set up an antenna, and shows diagrams of nice outdoor antennas, complete with lightning switches, passthroughs to get them into the house, and grounds.  But for those who didn’t want to go to all that bother, it also shows the self-explanatory method shown below for using the house wiring as an antenna.  The same idea was featured on this side of the iron curtain, as can be seen at this post.  Both great minds had the same idea:  Connect a radio to the house wiring, using a capacitor to let the RF through, but keep the high voltage out.  It’s a great idea unless the capacitor develops a short, in which case the headphones on your head suddenly become energized with the household current.

SovietMyFirstRadioPowerLineAntenna

Many an American kid got his start in radio when he discovered Alfred Morgan’s book in the elementary school library.  I wouldn’t be surprised if there were Soviet kids who did just the same thing when they discovered Borisov’s book.

This book, and thousands of other old Soviet books and magazines, can be found at can be found at Журналы СССР.  Even if you can’t read the text, the site is worth exploring.



Some Advice From Your Substitute Teacher

Greetings from Your Sub!

Dear Student:

As I’ve mentioned in previous posts, I occasionally work as a substitute teacher in Minnesota.  From time to time, students will ask personal questions about me, and more often than not, the answer I give is “Google me.”  On the off chance that some student took me up on that request, I applaud your curiosity and welcome you to my blog.

As you might have guessed (yet surprisingly, many students have not figured this out), I do not earn a living substitute teaching.  In fact, it would be very difficult to do so, since it pays only about $130 a day in most districts.  I’m actually an attorney, and I get most of my income by providing continuing legal education programs to attorneys in several states.   For the skeptics who want to see my attorney license, here it is.  And for the more justifiable skeptics who want to see my teaching license, here that is.  If you’re curious why I enjoy working as a sub, that’s explained at my earlier blog post.

Why I Told You to Drop Out of School

Most of the students I have occasion to teach are great.  And on the relatively rare occasions when they’re not, I don’t need to come back!  That’s the nice thing about substitute teaching.  If I don’t like my work environment, I’m only stuck there for one day, and I can easily find a better one.  If I want to work some particular day, there are almost always numerous options, and I’m free to chose any of them.  Or I can simply take a day off whenever I feel like it.  So if I’m in your class one time, it could very well be a random occurrence.  But if you see me a second time, it’s because I want to be there (or possibly because I forgot how bad you were).  Very few jobs have that level of flexibility.  Your regular teacher is probably stuck with you for an entire year.  But I have a choice.

But there’s one group of students that is a particular concern.  They’re a relatively small percentage, but they pose a frustration.  I’m not worried about the kids who misbehave.  The misbehaving students don’t really bother me, and if they do, I simply don’t come back.  The ones that cause frustration are the ones who appear to be totally disengaged.  Occasionally, I give them a surprising piece of advice, namely, that they should drop out of school as soon as they are legally able to do so.

This probably comes as a surprising piece of advice, and I suspect that other teachers don’t say this.  But in some cases, it is in the student’s best interest.  (There is another possible course of action for them, which I’ll explain in a minute.  But my advice that they drop out of school is an improvement over what they are currently doing.)

As far as I can tell, there are three reasons for you to be in school.  You are apparently already aware of one of them, or maybe even two of them.  But you don’t understand the third reason.  And unless you understand the third reason, there’s really little reason for you to be there, and you would actually be better off just dropping out of school.

Reason 1: The Compulsory Attendance Law

gavelYou already know about the first reason for being in school.  You’re in school because you have to be in school.  Specifically, there is a Minnesota law that says you have to be in school until you are 17 years old.  If this is the only reason you are in school, you are engaging in a tragic waste of time.  At the end of the day, you are an day older, but you have absolutely nothing to show for it.  In your case, the law is doing more harm than good.  It’s unlikely that you’ll be able to convince anyone to change the law.  Therefore, if this is the only reason you’re in school (and for a handful of you, it apparently is), then my advice stands.  You will be better off if you drop out of school.  If you do drop out, you won’t learn anything, and you won’t get a high school diploma.  But if you continue as you are now, those things aren’t going to happen anyway.  So rather than continue to waste your time, my advice still stands.  You’ll be better off if your drop out the moment you’re allowed to do so legally.  Here is the Minnesota law on compulsory attendance. In general, it says that you can drop out the day you hit 17.  And that will work out better for you than what’s currently happening.  On behalf of the voters in the state who gave you this law, I apologize that you have to wait this long.

Reason 2:  Getting a Diploma

My advice changes, however, if you are in school not merely because you have to, but because you want a high school diploma.  If you attend school for thirteen years and do the bare minimum, then you’ll get a piece of paper from the school district attesting to this fact.

I don’t wish to unnecessarily downplay the importance of receiving that piece of paper.  There are certain jobs which will require your having that piece of paper.  And if you research the history of the diploma pictured here, you’ll discover that a lot of brave people who went before you fought for the right of everyone to earn that piece of paper.  So if you’re in school with the goal of earning that piece of paper, then I guess perhaps I’ll take back my advice.  Perhaps you shouldn’t drop out.  Earning the diploma is not particularly difficult, but there are some hoops you will need to jump through.  And you can’t do that if you continue to be as disengaged as you were when I saw you.  If you just sit there every day and make no effort to do the things the teacher asks you to do, then I have some bad news for you:  You’re not going to get one of those pieces of paper.  So if that’s the case, my original advice still stands.  You’ll be better off if you drop out as soon as you are able.  Your time in school will be utterly wasted.  You won’t have anything to show for it.  You won’t be any smarter, and you won’t get a diploma.  If you drop out, at least maybe you can start earning some money.  And you’ll probably learn more than if you wasted all that time just sitting in school doing nothing.

But perhaps I just caught you on a bad day.  You didn’t want to learn anything from the sub, but perhaps you occasionally let your other teachers teach you something.  If that’s the case, then I take back my advice, and I tell you now not to drop out.  At least you’ll get that piece of paper.

Before I tell you my final reason for being in school, I have a couple of secrets for you.  The first is that the piece of paper, the diploma, has much less value than you think it does.  It is the bare minimum requirement for a lot of jobs.  So if you don’t have a diploma, you will be excluded from most of the economy.

But especially after a few years, nobody will really care if you have a high school diploma.  (To a large extent, that’s also true of college diplomas, but I’ll talk about that some other time.)  It’s just a piece of paper.  People will look down on you if you don’t have one, and you’ll be excluded from most jobs if you don’t have one.  But other than that bare minimum, nobody will really care if you have one.  In short, it’s not a particularly worthy goal in and of itself.  Yes, it’s something you need.  But nobody will be impressed that you have it.

The other little secret is that the school board, the administration, and your teachers have various incentives to make sure you get a diploma.  It reflects poorly on them if you drop out (unlike your substitute teacher, who doesn’t really have any incentives one way or another, and who can thus speak the truth).  Because of those incentives, your teachers will help you and do everything in their power to make sure you get a diploma if it is humanly possible.

Along the way, there will also be some standardized tests.  Your teachers also have have various incentives for you to do well on those tests.  But even more so than with the piece of paper you get after 13 years, nobody else really cares how well you do on those tests.

Your teachers might even cut corners to “help” you graduate.  For example, they might say that you passed the class, when you really didn’t learn anything.  You get the diploma, they get credit for making sure you got one, and everyone is happy.

In most cases, your teachers and administrators are much more motivated than this.  They actually want you to do well because they are good people.  They became teachers because they actually want their students to learn, and the good ones could have made more money by doing something else.  But while they have incentives to make sure you get a diploma, they don’t really have any incentive to prepare you for life.  They’re good people, but they have their limits.  At some point, as long as they make sure you get a diploma, they’ll eventually give up.  Anything beyond just getting the piece of paper is your responsibility.

For them, it’s a success if you graduate, and nothing more is expected of them.  But all you have to show for it is a piece of paper.  They were successful in getting a diploma in your hands.  But will you be successful?  It will take more than that piece of paper to make you a success.

The Third Reason for Being in School

brainThat brings us to the third reason for being in school.  We’ve already addressed the first two:  The first is because you have to be there, which is not a good enough reason, in my opinion.  The second reason is so that you can get a diploma, which is just barely a good enough reason to stay.  It’s great for your teachers, because they get credit for graduating you.  But who is more important, you or your teachers?

If you think you are more important, then you need to think about the third reason for going to school.  And that third reason is to actually learn something.  And unfortunately, there is only one person who is ultimately responsible for that, and that person is you.

Now, I will admit that some of what you learn in school is utterly useless.  As you put it, you will never need to apply this information “in the real world.”  But there’s actually less of that than you would think.   And unfortunately, neither I nor anyone else will sit down and tell you what is useless and what is important.  You need to figure that out yourself.  In fact, figuring out what’s important and what’s not important is the single most important thing that you’ll actually learn.  And to learn that, you’ll need to be exposed to both the useless and the useful information.

And even though it’s not immediately obvious, much of what you learn in school will actually be helpful in life.  However, in most cases, it will not be directly helpful.  For example, it’s unlikely that you will ever need to use the quadratic formula.  It’s certainly not necessary that you have it memorized, since you can look it up in the unlikely event you need it.  But even though you will not directly apply this one piece of knowledge, there are many times that you will need to indirectly apply the knowledge you have learned.  You need to be able to recognize that there is such a thing as the quadratic formula, and you will need to solve similar problems in life.  Very few will have anything to do with mathematics, but the same problem-solving skills will apply.  Unfortunately, I can’t prove this to you.  It’s one of those things where you’ll have to just take my word for it.

What you are really learning is that certain types of questions can be answered, some of them can be answered easily, and some can be answered only with great difficulty.  You will also learn that some questions can’t be answered.  Being able to recognize the difference is the main thing that you are learning in school.  You will be successful if you learn how to recognize the problems that can be solved easily.  If you don’t learn this, you’ll waste your life trying to solve problems which have no solution.  It’s best to simply avoid such problems.  And in school, you’ll learn how to recognize them.  And unfortunately, for now, you’ll just have to trust me as to the truth of that statement.

You should also be aware that other people will frequently give you the wrong answers to questions.  Sometimes this is intentional, but the motivation of the other person is rarely relevant.  The important thing to know is that you will often be presented with information that is wrong.  This means that you need to be able to figure out things for yourself.  Your teachers might also give you misinformation.  But in the process, they will also be giving you the tools to figure out that the information is wrong.  Again, the facts that you learn in school are generally unimportant.  But in the process of learning them, you will also learn how to separate reality from the fantasy that is presented by someone else.  The piece of paper won’t help you with this–it’s necessary to go beyond the bare minimum.

In summary, if you are only in school because you have to be, then my advice stands:  You should drop out, because you’re wasting your time.  If you’re there to get a diploma, then I guess that’s marginally useful  But at the very least, you need to make some effort to meet the minimum requirements for the diploma.  Merely showing up isn’t quite enough.

But since you’re going to be there anyway, then you may as well make an effort to learn something.  If the classes you are in have absolutely no relevance to your life, then talk to your counselor, and get put in different classes.  But even if that’s not possible, you’ll probably learn something that’s useful, albeit not immediately useful.

I enjoyed having you in class, even if I told you to drop out.  But I hope you understand that it would be better for you if you don’t drop out.  But in order for that to work, you’ll need to start actually doing some of the things the teacher asks you to do.  If you don’t, then my original advice stands.

If I was wrong, and my advice doesn’t apply to you, there’s no need to prove that to me.  There’s only one person to whom you need to prove that I was wrong, and that is yourself.

Sincerely yours,

Richard Clem, Minnesota Substitute Teacher



1948 Speaker Phone

1948JanPM11948JanPM2Today, most telephones, either landline or mobile, contain a speaker phone function, but this hasn’t always been the case. Shown here from 70 years ago is a very early version, the Jordaphone, shown here in the January 1948 issue of Popular Mechanics. The article notes that groups could now sit in on meetings without individual telephones with the instrument that “looks like a console radio.”

The article also stressed one important fact, that the Jordaphone “is not actually connected with the telephone line.” As those of us who grew up in the 1960’s and earlier are aware, the telephone line and “the instrument” were sacred, they were property of Ma Bell, and that tapping into the line was absolutely forbidden.

This device had a workaround. The telephone handset was set in a cradle in the top, and inductively coupled to the Jordaphone.



1928 Homemade Fuses

1928JanPMIf you need a fuse but the store is closed, then you can just make your own the way they did it 90 years ago, as shown in the January 1928 issue of Popular Mechanics.

The exact current values are not shown, but the accompanying article describes the use of the fuse on a radio. The fuse itself is made of tinfoil from a gum or candy wrapper. For the A battery, the article called for a strip 1/16 inch thick. For the B battery, which would use less current, it called for a strip 1/32 inch wide.

The idea had been submitted to the magazine by one R.J. Williams of Chicago.



New Year’s Day Stalingrad, 1943

13th Guards Rifle Division at Stalingrad. Wikipedia photo.

Here was the scene in Stalingrad on New Year’s Day 75 years ago, 1943.  The battle lasted into February, when the Soviets won a decisive victory, but only after over 1.2 million total casualties; with 478,741 officially listed as killed or missing.



Dec. 31, 1917, Bray-sur-Somme, France

Bray-sur-Somme, December 31 1917 (Art.IWM ART 4915) image: a view across the roofs of buildings in Bray-sur-Somme, with a line of telegraph poles crossing the foreground. Copyright: © IWM. Original Source: http://www.iwm.org.uk/collections/item/object/23244

Imperial War Museum image. Bray-sur-Somme, December 31 1917 (Art.IWM ART 4915)  Copyright: © IWM.

This sketch was made a hundred years ago today, December 31, 1917, by British officer Major Geoffrey K Rose.  It shows the French town of Bray-sur-Somme.

Major Rose (1889-1959) served on the Western Front for three years, and made over 150 sketches during that time.  Bray-sur-Somme was initially occupied by the Germans in August 1914, but was evacuated in October of that year, with the front being north of town. For the next 26 months, including when this sketch was made, the town served as a center for rest and recuperation for the French Army, and later the British.

It is thus likely that Maj. Rose was on leave when he made this sketch. In March 1918 the town was, however, taken again by the Germans, and it remained in their hands until the town suffered heavy damage when the British re-took it in August 1918.

L'église Saint-Nicolas, vue depuis l'office du tourisme.

L’église Saint-Nicolas, Wikipedia photo.

Recognizable in the sketch is the distinctive tower of the Church of Saint-Nicolas, shown here in a modern photo.



Zeh Bouck and 1937 Shortwave Retailing

1937DecRadioRetailingThe avid shortwave listener (SWL) will probably dispute it, but this picture contains a certain glimmer of truth. Junior is tuning in a program on the short waves on the family’s console radio, much to the dismay of the rest of the family. The picture’s caption, in the December 1937 issue of Radio Retailing, notes that “novelty rarely wears well–We (radio retailers) have been headlining thrills…police calls, aircraft, ships at sea, distance merely as “dx” . . . so long that the public erroneously assumes that shortwaves have little lasting entertainment value.”

The accompanying article, “Is Our Short Wave Selling All Wrong?” makes a strong case that it is.  The author, writing under the pen name Zeh Bouck,  starts by saying that he was paid for listening to shortwave broadcasts, one of his jobs for the past fifteen years, and that the novelty, if it ever existed, wore off a decade earlier.  He starts by noting that retailers were selling the shortwaves as a novelty, on which listeners could hear the sounds of Big Ben, along with “aircraft! Amateur Stations! Police!”

He then proceeds to show why the novelty wears off so fast. The hams are “vaguely reminiscent of a phonograph record with a crossed groove, and of similar interest to anyone but an amateur. Police broadcasts are distinctly a novelty and hold no permanent entertainment value except for some Milquetoast who derives therefrom a vicarious satisfaction at some drunk beating up his wife in a third floor rear.”

Fortunately, Bouck goes on to explain that there might be a right way to sell shortwave. He noted programs of actual entertainment value, and recommended that retailers get their hands on program guides.

The author, Zeh Bouck, was born John W. Schmidt in 1901, and held various calls over the years, starting with 2PI, until his death in 1946. He eventually legally changed his name to Zeh Bouck. He was a prolific writer about radio, including a number of articles in Boys’ Life. You can find a good biography of him at this link.