If you are looking for that funky accessory to outfit your geek palace, or just own a piece of electronics history, why not consider an antique radio? An antique radio will add warmth and character to the decor, unlike the monotonous black and beige plastic that most consumer electronics are built from today. Antique Radio refers to pretty much any radio built before 1950, but there are collectible radios that date even into the 1970s, such as early transistor radios, novelty radios of all kinds, and specialized radios such as communications receivers, military gear, and high end audio.

A quick history of Radio Technology: The Beginnings of Radio

1890's: Heinrich Hertz was able to detect sparks made in his laboratory with circuitry a few meters away with a detector circuit. Guglielmo Marconi was able to build on Hertz's work, and by 1896 he was able to send signals several kilometers. Improving his detector circuits, he was able to patent his invention in 1897, and opened the first radio factory in 1898.

1900s: In 1901 Marconi gained worldwide attention by sending a message across the Atlantic Ocean. Amateur Radio experimenters built spark gap transmitters and used cats whisker detectors to send morse code to each other. In 1904 John Fleming invented the Fleming Valve, the first Diode tube, and in 1906 Lee De Forest invented the first audio amplifier tube, the audion. With these inventions in place, the stage was set for the widespread adoption of radio communication.

1910s saw the widespread recognition of radio as a viable and valuable means of communication. At the beginning of the decade, the physics of radio were still not fully understood, and many people considered it black magic. Navy vessels were among the first to recognize the value of radio. in 1912 the HMS Titanic struck an iceberg, and the distress call of the dying ship was heard by dozens of other ships and shore stations, the drama was already being played out in the newspapers before the first surviors came ashore. Radio went to the front in WW1, and by 1920 most of the spark transmitters were gone, replaced by audion powered transmitters that could transmit clean sounding voice signals, and made much more efficient use of bandwidth than the old spark gap transmitters.

The 1920s: Growth of Commercial Broadcasting

Many of the amateur radio stations of the time were starting to gain quite an audience. In 1920, radio was about in the same position as the internet in 1992. A lot of experimenters were playing around with it, especially in industry, academic, and hobbyist circles, but it wasn't quite at mass-market yet. In 1921 KDKA in Pittsburgh PA was the first real commercial radio station to provide professional news broadcasts, entertainment, and commercials, and soon commercial radio stations were springing up in nearly every major city, along with religious broadcasters and hams. Sales of Radio Receivers exploded, growing from 500,000 in 1923 to 3 million in 1924. Circuitry improved in the new radios as well, as improved tubes made their way into production, and circuitry evolved from regenerative receivers, which had very poor selectivity to TRF, or Tuned Radio Frequency, which had several seperately tuned stages of amplification. Superheterodyne was developed by RCA in 1925, and became the dominant circuit design by the early 1930's.

The final piece of the puzzle which put a radio in nearly every home was the battery eliminator. Up until the late 1920s, most radios relied on several batteries to power the radio. Typically a mid-20's set used three batteries, a low voltage high capacity battery for the tube filaments, known as an A battery, a high voltage battery of about 67 to 100 volts, known as a B battery, and a C battery to provide grid bias. The batteries were messy and expensive to replace, so the radio was often relegated to a basement room or garage. A battery eliminator was often sold seperate from a radio, and consisted of a large transformer, capacitors, and a rectifier tube. They were expensive at first, often costing nearly as much as a good radio, but they got smaller and cheaper and were incorporated into the cabinet of most radios by the end of the decade.

The 1930's: Radio Reaches the Masses

The Great Depression decimated the ranks of radio manufacturers as it did to most other industries, but if anything, the depression increased the public's appetite for radio. For a couple of cents worth of electricity, the owner of a radio could be treated to hours of entertainment, unlike most other forms of entertainment. Radios also found their way into automobiles in increasing numbers as well. As fascism and war descended over Europe at the close of the decade, people were able to get live accounts of the growing storm.

Radios got much cheaper as well, a typical radio with a battery eliminator in 1927 cost about $125 in the Sears Catalog, which was about 5 weeks salary for the average working man. By 1939, a typical AC/DC radio the size of a toaster could be had for about $10, only a couple of day's wage. The AC/DC radio allowed radios to be manufactured much cheaper by eliminating the power transformer, a very expensive part of the radio. The radio was designed to use a tube set which had the heaters wired in series, and the voltage drop across all of the tubes added up to 115 volts, which is what comes out of the wall. Tubes which need a lot of power, such as the rectifier and audio output tubes dropped 35 or even 50 volts, while RF amplifier and Oscillator tubes dropped only 12 volts.

By the late 1930s, shortwave bands were added to many radios, as people anxiously listened for news accounts of the growing conflicts overseas. New materials were also finding their way into radios. Plastics such as Bakelite, Urea, and Phenolic were cast into radio cabinets, and started to displace metal and wood as primary cabinet materials, which led to many novel designs and colors. Styling and design became as important as price and performance, and the late 1930s was considered the golden age of radio, both in terms of the radios themselves and the programming heard on them.

The 1940s and Beyond

Radios sold well in the early 1940s until World War 2 interrupted production of radios for civilian use from 1942 to 1945. Radio makers prospered building equipment for the Military, but civilians had to make do with what they had. Often repair parts were in short supply, and repairmen often had to adapt the radios to use the tubes and other parts that were available. Note: If you are restoring a radio that has these wartime adaptations do not undo them, as they are a valuable historic reference much like a rationing sticker on an antique car of the period.

After the war, radio production resumed quickly, and many mass-production techniques perfected in the crucible of war found their way into the new sets. These include miniature tubes, printed circuit boards, and new materials such as polystyrene. Another major innovation was the introduction of FM Radio, which largely eliminated the static encountered on the low frequencies of AM. It took a while for FM to take off, since the early FM sets worked lacked the sensitivity we take for granted today, and at first there were few FM stations to listen to.

The 1950s: Radio begets TV, and steps out of the Spotlight

After 1950, consumer's attention turned away from radio to Television. When the new TV came in the door, the expensive console radio lost its place of honor in the living room, and was relegated to the corner, the bedroom, or the attic, while smaller radios made their way into the kitchen or garage. Most new radios were built cheaply and became disposable when they broke. In 1957, Sony introduced the Transistor Radio, and soon the era of the vacuum tube was over. A few radios from the era are collectible, including Zenith Transoceanics, early transistor radios, novelty radios, and communications receivers built by Collins, Hammarlund, and Hallicrafters.

The 1960's: The Demise of the Vacuum Tube, the rise of Solid State.

By the mid 1960s, vacuum tubes were nearly extinct in new radios. Transistors and other solid state devices made tubes obsolete, and made possible inexpensive radios that did not require periodic tube replacements, ran cooler, could easily be made portable, and performed as well or better than their tube-type predecessors. Except for the picture tube, most television receivers became solid state within a few years as well. For a while there were hybrid chassis, due to the fact that development of high-power and high-voltage solid state devices required by television receivers took longer to develop than the lower voltage and lower power devices required by the typical radio.

The 1970s: The Japanese take over Consumer Electronics

By the early 1970's, completely solid state TV sets were the rule. During this period as well, Japanese manufacturers of radios, TV's, and Audio Components became household words, such as Mitsubishi and Sony televisions. Panasonic (Matsushita), Kenwood, Onkyo, and Pioneer, among others became the dominant suppliers of high quality audio gear around the world during this time. American domestic manufacturers declined, and although many of the venerable nameplates of the radio industry survived, they too were increasingly manufactured in Japan and in other Asian countries, such as Korea, Taiwan, and Malaysia. Perhaps these early Japanese audio components will become the collectibles of the future.

Major Classes of Collectible Radios

Here are the major classes of collectible Radios

Very Early Radio Gear:

Very early radio gear includes radios that were built before 1920. Look for spark gap transmitters, coherers, sets, cat whisker detectors, and very odd looking vacuum tubes. Often tubes of this era were experimental in design, and sometimes even homemade using bits of lightbulb filaments, foil, screen, and so on. Often these sets were built on a plain board called a breadboard that laid all of the components out in the open. Military gear from this era is especially prized, and rare.

1920's Radios

The first major advance in home receivers in the 20's was the mass production of standard types of vacuum tubes. Early tube types were the WD-11, and by the mid 20's other types such as '01A's, 27, 45, and 80 were common tube types. In the early 20's breadboards were pretty much the rule, since advances in technology were coming along at a rapid rate, and the breadboard allowed the hobbyist to change things easily without being constrained by a fixed chassis or cabinet. As commercial stations started to spread by the mid 20's, and radio moved from being a hobby to being a common form of home entertainment, literally hundreds of manufacturers of radio equipment started offering pre-built receivers. Atwater Kent, previously a maker of automobile electrical and radio parts built one of the first commercial receivers on yes, a breadboard. Soon however, it started to build better and more complex receivers in wooden or metal cabinets, with the components mounted on a metal chassis, and within a couple of years it was one of the largest manufacturers of radios in the world. Other successful manufacturers of the era were RCA, which developed the first Superheterodyne receiver, Zenith, Philco, and Silvertone, which was sold by the granddaddy of all retailers of that era Sears Roebuck. Many others followed, but most receivers of that era had 3 basic designs, listed in ascending order of sophistication :

Regenerative, which acheived adequate amplification by feeding part of the signal back through the amplifier tube. High gain could be acheived, but at a cost of poor selectivity, and local interference.

Tuned Radio Frequency or TRF receivers used a seperate tuned circuit for each stage of amplification. A peek inside will reveal that a TRF set will have several nearly identical stages tuned with a ganged variable capacitor, and nearly identical tubes for the amplification stages. A better TRF set would often use 4 or 5 stages of amplification with a type 27 tube, and parallel type 45 tubes for audio amplification. TRF sets remained popular into the early 1930's, partly because of their simplicity, and partly because of patents held by RCA on the superior Superheterodyne design.

The Superheterodyne receiver was introduced by RCA in the mid 1920's, and became the envy of other radio makers due to the fact that a superheterodyne receiver could maintain a constant bandwidth and track well across the entire AM Broadcast Band. RCA held a tight grip on patents on the superhet design until the early 30's, when it started to license the design to other makers. The superhet design works by converting the received frequency to an intermediate frequency before it is amplified, allowing more efficient amplification and better receive characteristics. It is still the dominant receiver design today, outlasting even vacuum tubes.

Speakers

Until the late 1920s, most radios did not have a built-in speaker, but rather had provisions to connect either headphones or a seperately purchased speaker. Radio speakers of the era are popular collectibles in their own right, and many had fine quality artwork silkscreened to their grilles.

The 1930's through World War 2: Radios take many forms

Radios of the 1930's saw less in the way of radical changes in circuitry design than specialization and refinement, or simplification. Many if not most of the radio makers of the 1920s were snuffed out by the Great Depression, including sadly, Atwater Kent. The survivors got along by working to create radios that were more affordable to buy and operate, or cater to specialized wants and desires. This resulted in some of the most innovative and aestheticaly pleasing radios ever built, and created niches in the marketplace for newcomers. The signature radio of the early 1930's was the Cathedral. Built by Philco, RCA, and others, the Cathedral had the classic arch shape, with a metal chassis inside the bottom of the wooden cabinet, with the speaker filling the top part. Much simpler and more compact in design, and less costly than the complex and heavy console designs of the late 20's, the Cathedral became the most popular design of the early 30's, with models such as the Philco 60 and 90. A variation of the Cathedral was the Tombstone, named for its characteristic shape. The console was still sold for those who wanted a nice radio in the living room or parlor. Some of the high end sets, such as the Zenith Stratosphere and E.H. Scott Philharmonic boasted enough power to fill an auditorium and sounded great even by today's standards.

The majority of people in the 30's were not wealthy enough for a Scott or a Stratosphere, but often wanted an inexpensive, compact and stylish radio for the bedroom, workshop, or workplace. As the electronic guts of the radio became more or less a commodity item, makers of radios sought to distinguish themselves and fill the market for inexpensive radios by building unique cabinet designs, often using innovative materials. Molded Bakelite was a common material in radios of that era, and Emerson, Zenith, Fada, Crosley, and many others made extensive use of this versatile but fairly inexpensive material. Similar to Bakelite was Urea Resin, which could be molded into a choice of colors, but most radios were off white in color. Plastics really got colorful with the introduction of Phenolic Resin or Catalin. Many of the early Catalins were inexpensive radios for the kitchen or kid's room using a basic radio chassis, but today are some of the most sought-after collectibles. This is due partly to their innnovative and interesting Art Deco designs, but also partly because few Catlins have survived the decades due to their disposable nature, and the tendency of their cabinets to crack as the early plastics shrank over time. Novelty radios were built as well and are very collectible, capitalizing on the stars of the time, such as the Mae West (and its famous knobs), radios built into bars, radios with Mickey Mouse ears, and so on. Other notable designs were the Sparton Bluebird, which had an Art Deco cabinet backed by a circular blue mirror, and the big black dial Zeniths. The Zeniths of the late 30's used a signature black circular dial in everything from their table radios to their top of the line Stratosphere consoles. I have a Zenith 7S363 from 1939 I lovingly restored, and black dial Zeniths are a desirable collectible today.

As the Second World War approached, people started listening to broadcasts from Europe and Japan for breaking news and developments. Shortwave bands were added to most mid-priced to top of the line receivers which could pick up foreign broadcasts from Britan, France, and Nazi Germany, and brought news of the Nuremburg Rallies, the invasion of France, and the Battle of Britan. Dedicated Shortwave receivers were built by companies such as Hallicrafters, Hammarlund, National, and Collins and were sold to hams, and to shortwave listners as well. Many of these receivers such as the Hallicrafters SX-28 were built extremely well, and featured some of the most advanced technology and best workmanship of that era. Good examples of these and similar radios can still be found today for reasonable amounts of money, although prices for them are rising. During the war, the domestic radio manufacturers dedicated most of their production to producing equipment for the war effort. Replacement parts, especially tubes for radios were often scarce, and many times repairmen had to make do with makeshift substitutes by building adapters or modifying circuitry. As I mentioned above, if you come across one of these modifications while restoring an old radio, it is considered bad form to undo it, as it would be to peel the gas rationing sticker from the windshield of a World War 2 era automobile.

Immediately after the war, civilian production of radios resumed quickly, and manufacturers often took advantages of military surplus bargains to meet pent up demand for radios by incorporating surplus tubes into their designs, but for a couple of years most designs were leftovers from before the war. I have two Philco "bubbletop" bakelite radios built in the first year or two after the war that use two completely different tube sets. One uses all Locktal tubes, and the other one uses a mix of miniature and Octal tubes. Like automobiles in the immediate postwar period, radios of this era (1946 to 1948) were almost identical to 1941 models. Meeting the huge pent up demand for radios was more important than bringing out new and innovative designs.

The 1950's through today

As the 1950's approached, several major changes in radios took place. First is the universal apoption of Miniature tubes which had an all-glass body and used less power and threw off less heat than their predecessors, the Octal and Locktal. In 1950, the standard AM radio of the day nearly all had the same set of tubes inside: 12BE6,12BA6, 12AV6, 35W4 and 50C5. Variations of these tubes were the 12AU6, and 35C5 for radios with more than 5 tubes. Another major innovation was the introduction of Frequency Modulation or FM. Zenith was the leader in early FM sets, but Philco and Emerson, as well as others soon followed suit. FM eliminated the static that plagues AM listeners to this day. The increased bandwidth allowed for true high-fidelity reception, although most early FM receivers fell short of this goal. FM was slow to gain popularity due to its limited range aggravated by the fairly insensitive receiver designs of the day. By the 1960's, improved solid-state circuitry lessened the handicap of limited range. A not so good innovation of the 1950's from the collector's point of view was the continued quest to build radios cheaper and cheaper. Innovations such as printed circuit boards, cheap polystyrene cabinets, and more generic designs undermine the desirability of many 1950's era sets. A couple of exceptions are the Zenith Transoceanic, a portable multiband shortwave and AM receiver, some of the novelty radios produced, some early hi fi equipment, and the first trasistor radios. European imports from the mid 50's are also intresting finds but difficult to restore. Television also elbowed aside radio from the spotlight, which also has led to the decline of radio and radios as well. Early television receivers are collectible as well, such as the very first (pre 1950) models and the Philco Predicta, but most garden variety television receivers of the 50's tend to be spurned by collectors as the big ugly, ungainly, and unreliable boxes they were, and were cast away for more compact designs or for Color TV's when they became affordable and had widespread programming by the mid 1960's.

By the mid 1960s, vacuum tubes were nearly extinct in new radios. Transistors and other solid state devices made tubes obsolete, and made possible inexpensive radios that did not require periodic tube replacements, ran cooler, and performed as well or better than their tube-type counterparts. Except for the picture tube, most television receivers became solid state within a few years as well. For a while there were hybrid chassis, due to the fact that development of high-power and high-voltage solid state devices required by television receivers were took longer than the lower voltage and lower power devices required by the typical radio. By the early 1970's, completely solid state TV sets were the rule.

Where to find Antique and Collecible Radios

Back when I was in high school in the 1970's, I could find many of the collecible radios of today at the local church flea market, auction, or yard sale for only a couple of dollars each. I picked up a nice Crosley clock radio from the late 40's for only a couple of bucks, and other easily repaired radios for the cost of a candy bar and soda. Today that radio would be worth over $100 USD! Those days are gone forever, yesterday's trash is today's treasure. It takes a little more looking these days, but here are a few good places to look:

eBay has them by the thousands, but also has bidders by the thousands as well. Sometimes certain radios will fetch ridiculous prices there.

Hamfests are electronics flea markets put on by hams, which bring their old stuff out to a parking lot or carnival ground. Oftentimes hams are also old radio collectors. Sometimes they have some antique radios sitting out with their obsolete computers, dot matrix printers and antenna hardware. While the selection may not be always that great, prices are likely to be more reasonable than E-Bay, plus you have the opportunity to meet and socialize with like minded people, where you can hook up with groups of radio collectors.

Radio Clubs have meets periodically, and one of the main attractions is a flea market similar to hamfests, only they tend to have more radios and less obsolete computer gear. Some major regional clubs are the Mid Atlantic Antique Radio Club and the Antique Wireless Association. These clubs usually have a website, newsletter and other resources that provide valuable information to collectors and restorers about many aspects of radio collecting and restoration, including schematics, parts, restoration techniques, and history of various companies and personalities in the radio business.

That about does it for now, I hope you enjoyed my little node. One of these days I want to extend this node by doing a howto on restoration of an antique radio. 73 and signing off!