Radio Hits The Road
You had to be rich to own a car radio in the late 1920s and early 1930s. Installed, a decent set might cost you $175. Since you could by a new 1930 Chevrolet sedan for $695, a radio represented a pretty hefty piece of change.
Installing the radio was no easy task either. It required the tearing a car apart—removing the dashboard and parts of the roof, and drilling holes in the cowl, floor, and toeboard—and then somehow putting it all back together again. A slap-dash installation could leave a car crippled for life.
Earl (“Madman”) Muntz, the legendary Los Angeles auto dealer, began his career in Chicago in 1928 as a radio installer. He told me in 1972 that it once took him seven solid days to put a radio into an uncooperative Cord L-29. Two days, he said, was normal for a Chevy. And Muntz was one of the best and fastest in the business.
A radio put a major strain on a car’s electrical system, even though it came with a battery of its own. Then there was the fire hazard. Paul Calvin, the founder of Motorola, once recalled the time in 1930 when he went to a banker in Chicago to get a loan for his struggling radio business. To show how great car radios were, Calvin installed a new Motorola free of charge in the banker’s Packard. It worked fine, and the banker drove away all smiles.
A block down the street, though, the car started to smoke. Within two blocks flames from a short circuit had singed the paint on his hood. Despite the banker’s toasted Packard, Calvin got his loan. When he told the story later, Galvin usually added that his own Studebaker, which his engineers used for research and testing, caught fire dozens of times.
Car radios were also deemed hazardous in the way that cell phones are today. In early 1930 the Massachusetts registrar of motor vehicles proposed a regulation to prohibit drivers from playing radios while a car was in motion. (The city of St. Louis introduced similar legislation.) It all came to a head on February 26, 1930, when the Massachusetts Public Works Commission held a hearing on the question. Opponents of car radios argued that they distracted drivers and caused accidents, that tuning them took a driver’s attention away from the road, that music could lull a driver to sleep, and that with open cars still common, radios distracted the drivers of other vehicles too.
The Radio Manufacturers Association, established to fight just such regulation, countered that the commission was wrong on each point and that radios actually prevented accidents by keeping drivers awake and alert. Of some 200 people who attended the hearing, only 5 were strongly anti-radio, so the Massachusetts proposal died.
The earliest car radios were simply home sets that drivers lugged out of the house, complete with batteries, and perched in or on their cars. These sets couldn’t be played with the engine running because the unshielded ignition caused all sorts of noise and static. You could, however, put a radio into a car, drive out to the country, shut off the engine, set up an antenna, and get pretty decent reception—sometimes. But until at least the mid-1920s, there wasn’t much to listen to.
Around 1922 a very few enterprising motorists began to install radios permanently inside their cars. No special automotive sets were available yet, so they used household models. They still had to shut the engine off to listen.
The first man to go into car radios commercially seems to have been William M. Heina, who founded the Heinaphone Corporation around 1926. Heinaphone was soon taken over by a group called the Automobile Radio Corporation (ARC), which made Transitone sets, and Philco bought the entire operation in 1930. Just before the buyout A. A. Leonard, the chief engineer for ARC, hit on a practical way to eliminate ignition interference. This was such a basic and important development that it’s still used today in modified form.
Leonard started by investigating the source of the interference. He discovered that an engine’s high-tension ignition wires act as miniature antennas broadcasting at frequencies that vary with their length. This oscillation comes about because of the abrupt change in current through the wire when the spark plug fires. The same type of high-frequency generation occurs when any switch is opened or closed. Leonard damped the oscillation by placing screw-in resistors, called suppressors, between the spark-plug wire and the plug.
Suppressors did a good job of eliminating noise, but unfortunately they also reduced engine efficiency by decreasing the intensity of the ignition spark. Fuel mileage could drop anywhere from 10 to 50 percent with the installation of a radio, even when it wasn’t turned on. Moreover, when Leonard’s suppressors reduced the high-tension interference, they brought out low-tension static, which had been there all along but hadn’t been noticeable before. The nation’s radio installers began a long battle against a bewildering variety of odd noises produced by an automobile’s generator, ignition breaker points, and other electrical sources.
Some of these noises were taken out with additional suppression devices and others with shielding—a copper box around the receiver. Yet each solution to a source of interference created new problems of its own. Pity the poor driver of a radio-equipped car in fog or rain, for example. Moisture-induced ignition leaks went everywhere but to the spark plugs, and even in weather that was merely humid, engines with massive copper shielding and ignition suppressors often wouldn’t start.
Another troublesome feature of early car radios was the dreaded and unreliable B battery. The car’s normal A battery supplied 6 volts of direct current to the starter and accessories like headlights and horn. It also powered the filaments of the radio’s tubes. But the plates and grids of the tubes required higher voltages—from 90 to 135 volts DC. This higher voltage came from a secondary battery, called the B battery. (Home radios also had separate A and B batteries until the late 1920s, when sets were built to run on household alternating current.) As radios became more complex, a C battery was sometimes required to power multi-element tubes that needed several different voltages.
Sometimes the B and C batteries were combined in one large case. Big, bulky radio batteries became so common that by 1929 many high-end car bodies came from the factory with battery-box cutouts in the floorboards. But that was just a stopgap; the ultimate solution lay in finding a way to power the radio with only the A battery.
The American car-radio industry claims 1929 as the year of its birth. That was also the year home radio took off. Before 1929 radio had been a crazy quilt of widely assorted musical fare interspersed with religious and inspirational programming, advertisements for goat-gland extracts, and other programs of modest audience appeal. Then in 1929 “Amos V Andy” got a national hookup on NBC. The immediate and overwhelming popularity of that one show was credited with boosting home-radio sales by 23 percent in 1930 despite the stock market crash. Its success encouraged radio’s development as a mass entertainment medium.
Sales of car radios also shot up, because car owners didn’t want to miss the shows they had gotten hooked on at home, and as sets became less expensive, sales continued to increase. When prices didn’t fall fast enough for many Depression-strapped Americans, though, the public found out that cheap automobile radios could be worse than none at all.
The infamous Ajax radio of 1931 was marketed with a pyramid scheme. Ajax offered a “free” radio and installation in exchange for a $150 mortgage on the recipient’s car. If the car owner could talk six friends into installing $25 Ajax radios in their own cars, Ajax would tear up the first driver’s contract. It even paid commissions for bringing in more customers.
Unfortunately, most people could sell only one or two Aj ax radios to friends, so no one was getting out from under his mortgage contract. Pretty soon Ajax owned the titles to thousands of cars. The scheme finally went to court and was declared a fraud.
As they became more common, car radios continued to improve. By 1932 most automakers included as standard equipment a “pigtail,” or antenna lead, hung from the wire mesh in the roof. That year also saw the arrival of a device that replaced the pesky B and C batteries. It was known by several names—dynamotor, B-eliminator, Magmotor, Genemotor—and was powered by the car’s A battery, which was recharged during operation by the car’s generator. The dynamotor usually lived under the floor or the hood of the car and consisted of a 6-volt electric motor that drove a generator that created DC at the required 90 to 135 volts.
While it greatly simplified and shrank car-radio systems, the dynamotor also drew an extra few amps from the car’s A battery. Muntz always warned drivers not to use freewheeling while playing their dynamotor-driven radios. With no recharging on deceleration, the A battery could soon lose its charge and cause the engine to stall. Playing the radio with the car parked was another quick way to end up with a dead battery.
By 1933 the dynamotor began to be replaced by a less expensive, much smaller device called a vibrator. Most vibrators were about the size and shape of a radio tube, so they fit inside the receiver case. Early ones were hard-wired in place, but later vibrators plugged in with pins, like tubes. They came in two types, interrupter and synchronous. The interrupter —first developed by Bill Lear, who later became famous as the manufacturer of the Learjet—used a vibrating component to create alternating current, which was stepped up to a higher voltage and then rectified to yield highvoltage DC.
The synchronous vibrator used a second set of points that vibrated in sync with the first set and transformed the high-voltage AC back to DC, eliminating the need for a rectifier. This arrangement yielded pulsating DC, which was filtered to a constant level by a network of capacitors. The synchronous vibrator was more expensive than the interrupter type, but it could deliver more power to the radio, so it was used in upmarket cars like Buicks and Cadillacs. It created a trap for unwary installers because while battery polarity didn’t matter with interrupter vibrators, miswiring a synchronous vibrator would fry it.
I once interviewed Otto Weil, the chief engineer of PhilcoFord’s automotive entertainment division, and he told me he considered the vibrator a great blessing, but a mixed one. On the negative side, he said, it produced “hash,” a term coined to describe the interference generated by the abrupt wave fronts produced as the vibrator contacts opened and closed. “Getting rid of the hash was tough because it was present in ground currents throughout the set, and until these could be tracked down and controlled, you got that sound: hash-sh-sh-sh-sh!”
Another problem in the early days of car radio was that whenever you drove under telephone wires or through an iron bridge, you lost your radio signal. Distant stations also had a habit of fading, while nearby ones could blast you right out of your car. To remedy these variations in loudness, automatic volume control, made possible with multi-element tubes, was incorporated in the better sets in 1932.
The early 1930s also saw big-city police departments begin to install radio receivers in their patrol cars. Bill Balderston, who later became president of Philco, had a Transitone franchise in Chicago in 1930 and did a nice business installing sets in private and police vehicles. “The police would tune to station WGN in Chicago,” he recalled, “and whenever a police call would come up, it was broadcast over WGN. Often you’d be listening to music or a soap opera, and all of a sudden they’d cut in with an emergency message. So people had the added thrill of listening to real, live police calls. Trouble was, the crooks would also keep their car radios tuned to WGN, so they always knew everything the police knew.” In 1931 the Chicago police started getting two-way radios that operated on special frequencies.
Yet another problem in the early days was that car radios were not wired through the ignition switch, as they are now, and owners tended to leave their parked cars with the windows down, especially in the summer. So passers-by would often stop, reach through the open window, and help themselves. They wouldn’t steal the radio; they would just play it. Kids, especially, thought nothing of turning on the radio in a parked car, listening to a couple of afternoon thrillers, and then simply leaving, not bothering to turn the radio off again. Owners of open cars were even more vulnerable. Many a motorist came back to find the battery or batteries drained and the radio still on. Manufacturers soon began to install locks so that car radios could be played only with the owner’s key.
By 1932 automakers were starting to offer radios as regular production options. In 1933 radio manufacturers sold 724,000 car receivers in the United States; in 1934 the number topped 900,000; and in 1935 it reached 1,200,000.
In 1934 General Electric developed a car radio that played equally well inside a car or house. GE’s dual-purpose radio looked like a large loaf of bread. It was portable and could fit on the seat of an automobile, where it doubled as an armrest. Inside the car it was powered by 6-volt DC from the cigarette lighter. In the house it plugged into a 110-volt AC outlet.
Developments in car construction sometimes necessitated changes in radio design. In 1934 and 1935 General Motors’ Fisher Body division began putting all-steel roofs—the so-called turret top—on its cars. Before the turret top, most car radios had used the wire mesh that lay under the fabric roof insert as an antenna. The turret top was more durable than fabric and gave better protection against the elements, but it knocked wire roof antennas for a loop. One solution was to retain the wire-mesh antenna but put it underneath the running board. Unfortunately, the runningboard antenna was vulnerable to rocks, snow, and mud flung up by the front tires. Installers also put mesh antennas inside car doors and on the undersides of deck lids, atop the external spare tire, and as little “picket fences” that ran lengthwise along the roof.
Then someone came up with the idea of the whip antenna, which proved so simple and elegant that everyone wondered why no one had thought of it before. As early as 1937 Ford used a rotatable whip antenna mounted above the peak of the windshield. It could be pointed up for distant stations or down for nearby ones with a knob inside the car. Buick, Hudson, Pontiac, and Cadillac soon adopted the same idea.
Speakers had usually been mounted on the firewall, which separates the engine and passenger compartments, until about 1936, when Ford and others placed them above the windshield for “ear-level listening.” Before this time many car radios had their tuning knobs on the steering column and the receiver behind the instrument panel. Then in 1937 the first push-button radios appeared from several manufacturers. To set the station, you had to position a little setscrew for each button. The earliest of these push-button tuners stretched lengthwise up the steering column.
Another innovation of the late 1930s was first seen in the Philco Rolo-Matic and Delco Selectronic radios: an automatic station selector that could be moved with a foot control. A toe button that looked like a second headlight dimmer switch moved the selector from one station to another. Zenith offered a similar option. For 1941 Delco came out with the Super-Sonomatic, which included five shortwave bands. Chevy also offered a shortwave set in 1941-42; it cost only five dollars more than the standard radio.
World War II advanced radio technology considerably, and some military innovations found their way into postwar car radios. FM had been around since 1933, but it wasn’t introduced in car radios until 1951, when the German manufacturer Blaupunkt added an FM band to its premium AM radios. Transistor pocket radios arrived in 1954, and four years later instant-on transistors began to replace the bulky, slow-warming, and fragile tubes in car radios. The 1958 Cadillac Eldorado Brougham was the first car to include a transistor radio as standard equipment. That year, too, Pontiac and Oldsmobile offered optional transistorized pull-out radios that could use an in-car amplifier but also had a smaller amp and a separate battery pack, speaker, and antenna inside the pull-out head.
Then came the reverb, a short-lived forerunner of stereo equipment. A reverb inserted a slight acoustic delay between the front and rear speakers. This transformed 1960s car interiors into echoey rolling concert halls. Reverb sound amounted to a cheap substitute for stereo, and it quickly disappeared when the real thing became available.
A short-lived innovation was the 45rpm automotive record player. Despite their elaborate suspension mechanisms, these turntables suffered from bouncing needles on rough roads, and when drivers had to change records or re-position the tone arm, they made today’s mobile cell-phone users seem downright benign.
After vinyl records came four-track and eight-track tapes, which in turn gave way to cassettes, which are now giving way to CDs. With such a wealth of user-programmed music available, as well as scanning devices to tune microchip-driven radios, the thrill of pulling in a distant station while racing along the highway late at night is gone. Yet as the automotive sound system replaces the humble car radio, it’s still that magic box, even if it lacks the crackly charm it had in the 1930s and 1940s. But then, cars have lost some of that charm too.