Category Archives: Television History

How To Change Your Picture Tube: 1959

1959MarEESixty years ago, the March 1959 issue of Electronics Illustrated showed how to change your own picture tube, including diagrams for common configurations of both horizontal and vertical chases. The article explained how to short out the capacitors in the power supply, lest the handyman get zapped by high voltage from a set that wasn’t even plugged in. And it also explained how to avoid shards of glass flying everywhere if the tube imploded.

But it was the magazine’s cover that offered the reminder that to do this sort of job, you really ought to put on a sport coat. And while it’s not visible in the photo, it seems likely that this home repair man is wearing a tie.



1949 Television

1959FebPS11959FebPS2Seventy years ago, television was the center of every family’s interest, and the February 1949 issue of Popular Science provided numerous pointers on buying a set. As shown in the graphic here, a key concern was the size of the screen, which would limit the number of people who could watch. A hundred dollars would buy a 3-inch (diagonal) set, suitable for a single viewer. For two people, you could expect to pay $200 for a seven-inch set. And the most popular option for families was the 10-inch set, which would cost around $325.

The set was likely to need service, and the article recommended that a one-year guarantee would be worth any additional cost.



1949 Custom Installation

1949JanRadiotvnews

This handsome home entertainment installation appeared on the cover of Radio Television News 70 years ago this month, January 1949. While it appears to be a single console, it’s actually a custom installation of discrete components, a television, radio, and record player.

The issue provided guidance for dealers looking to move into this field, and suggested that thoughtful design and installation of such custom designs could be a lucrative proposition.



More 1928 Television

1928NovSciInvYesterday, we showed how Hugo Gernsback’s magazine Radio News was promoting television.  And the cover of his Science and Invention magazine for November 1928 was also engaged in the enthusiasm, with plans for the set shown here.

1928NovSciInv2

 

 



1928 Television

1928NovRadioNewsNinety years ago, it was clear that television was going to be the next big thing, and the November 1928 issue of Radio News contained all of the information needed to get started.

In addition to showing the plans for the mechanical set shown here, the magazine carried the television schedule of the magazine’s flagship station, WRNY.



1968 Police Dash Cam

1968OctPMFifty years ago this month, the October 1968 issue of Popular Mechanics shows this early rendition of a police dash cam.  According to the magazine, the Connecticut State Police had just started using the system shown here. The Sony camera was mounted on the dash, with a small microphone hanging around the officer’s neck. The back seat was taken up by the video recorder and monitor. The system ran entirely on 12 volts, at a cost of “less than $2000.”

The article quoted Sgt. Nelson Hurlburt, who reported that he simply let the tape keep running while on patrol. The tape had 30 minutes of recording time, so if he didn’t catch anything at the end of that time, he rewound the tape and started over. The lens was adjusted three times, at the beginning of his shift, again at 10:00 AM, and then again at dusk. The camera could automatically adjust to changing light levels during the day.

The magazine noted that the videotape evidence made a compelling case to the driver who was pulled over or, if necessary, in court.



1928 eCommerce Prediction

1928SepRadioNewsThere doesn’t appear to be anything in the way of explanation inside the magazine, other than the promise of “soon” on the cover. But Hugo Gernsback seems to have anticipated Amazon with this illustration on the cover of Radio News 90 years ago this month, September 1928.

The TV seems to be selling suits, and the viewer seems to have a button in his hand, getting ready to order as soon as the one he wants appears on the screen.



Transatlantic TV DX: 1958

1958SepRadioElecYesterday, we showed a regenerative preamplifier from 1968, designed by Hartland B. Smith, W8VVD, currently licensed as W8QX.  We promised that we would bring you another article by this prolific writer which appeared ten years earlier, in the September 1958 issue of Radio Electronics.

Smith begins the 1958 article by pointing out that he had been a licensed ham for 18 years and had his share of exciting DX contacts, but that he could “honestly say that none of these gave me quite as much a thrill as when I first saw an indentifiable transmission directly from London on the screen of my own TV set.”

And as shown by these pictures, that’s exactly what he did. The winter of 1957-58 was at the peak of the greatest solar maximum in recorded history, meaning that the maximum usable frequency (MUF) was frequently going above 40 MHz. This opened the possibility of pulling in Transatlantic TV signals, which is exactly what Smith set out to do.

Receiving the audio of British and French television signals was a relatively simple matter. The London and Belfast stations were on 41.50 MHz, and Caen, France, was on 41.25 MHz. Armed with nothing more than a prewar FM receiver, he was easily able to hear the audio. (Indeed, it wasn’t uncommon for American hams to listen to British TV audio on their six meter receivers.)

But being able to watch the video posed a much greater challenge. European TV used both different frequencies and different standards from American TV, so an American TV could not be used without some modification. So Smith set out to make the modifications. He focused on trying to pull in the powerful London station, which transmitted on 45 MHz with 200 kilowatts. The French station’s video was on 52.4 MHz, which was likely to be above the MUF even if the audio were booming in.

The first relatively modest challenge was the frequency, which was lower than that tuned by American sets. This was accomplished with a simple converter consisting of a single 12AT7 tube. With an oscillator frequency of either 33 or 123 MHz, this would bring the British signal to American channel 5, which was unused in his area. The antenna consisted of a two-element beam in the attic for video, with a folded dipole for the audio receiver.

Lisajous pattern on scope showing equal frequencies. Wikipedia image.

Tuning in the signal was one thing, but getting a visible picture required that the set be modified internally. The first issue was the horizontal sweep frequency, which was 15,750 Hz in the American set, but 10,125 Hz on the British signal. He did this by using an audio oscillator to produce the required 10,125 Hz signal, and feeding this and the horizontal oscillator into a scope. He then adjusted the horizontal and added components until the frequencies matched, as shown by a circular lisajous pattern on the scope.

The British vertical frequency of 50 Hz was deemed close enough to the American 60 Hz to not require any modification.

The final problem was that the video carrier in Britain was opposite of that used in the U.S. To correct this, he modified the video detector by reversing the cathode and plate.

With the modifications made, it was just a matter of listening on 41 MHz and waiting for the audio of the European signals to appear. This meant that the band was open, and it was time to turn on the video receiver.

This was a fairly elaborate process. The first step was to turn on the converter, and adjust the converter frequency until the “familiar out-of-sync zig-zag lines denoting a video carrier” appeared on the screen. (Anyone who watched TV in the 1970’s or earlier knows exactly what he means. If you’re too young to remember, click here for an example.)  At that point, the vertical hold would stop the picture from moving vertically, and then the horizontal hold control was adjusted (which might require some internal adjustment to make sure the control was in range). As he put it, “TV dx tuning is an art that is a little hard to describe on paper. It is best learned by experiment.”

He pointed out that picture quality would never be perfect. For one thing, there would almost always be multipath interference, since signals through the ionosphere might travel numerous paths. He noted that the ghosting problem might sometimes be acute. During one televised tennis match, he reported seeing at least 30 players batting 15 balls back and forth. But occasionally, the ionosphere would settle down momentarily, resulting in the identifiable images shown here.



1948 TV Census

1948AugTeleviserHere’s a snapshot of the state of television 70 years ago this month, Agusut 1948, from that month’s edition of Televiser magazine.  New York was still the nation’s hotspot when it came to the new medium, with just over half of the nation’s sets in the New York metropolitan area.

Minneapolis-St. Paul now boasted 5600 sets, 3900 in private homes, with the remaining 1700 in public places.

According to the magazine, over 64,000 sets were rolling off the assembly lines each month.  By comparing with the previous year’s numbers, it was clear that TV was growing fast.  In September 1947, the same survey had shown just over 93,000 sets, with well over half in the New York area.  Minneapolis and Milwaukee hadn’t appeared in the 1947 survey, but were now growing TV markets.



1938 TV Images

1938June20LifeEighty years ago today, the June 20, 1938 issue of Life magazine carried these images of a broadcast by WNBT New York.

The June 7 broadcast of s scene from the play Susan and God starring Gertrude Lawrence originated at Radio City, and these images were captured by the editors of Electronics magazine.  Life noted that the blurriness of the images was due to the fact that a still camera couldn’t capture a clear image of the moving picture, and the photography was further hampered by the small size of the TV screen.

1938June20Life2