How to Identify Old Radios

You've just acquired an old radio, but apart from the manufacturer's name on the front, you don't know a blessed thing about it. Learning more about your radio may satisfy your curiosity, or it may serve a practical purpose such as helping you get repair information. Here's how to go about it.

I can't find my radio on the Internet—does that mean it's rare?

No! The fact that your radio is not listed on the Internet (or in a book) doesn't necessarily mean that it is rare. Tens of thousands of different radio models were manufactured over the decades, in the US alone. Many thousands more were manufactured worldwide.

No book lists all of those radios. No website lists all of them. No combination of books and websites lists all of them. There are simply too many.

Honestly, most of the radios sold over those decades are not very interesting. For every rare and unusual radio, there were thousands of cheap and common radios. Many cheap and common radios are omitted from books and websites because there's nothing interesting to say about them.

Most antique radio websites, including this one, list radios that the webmaster happens to own. The world is full of interesting radios that I don't happen to own, but you won't find them mentioned here.

So, if you do an Internet search and you find no mention of your radio, don't jump to the conclusion that it's a rare treasure. The silence only means that nobody on the Internet felt like writing about that model, among the many thousands of others.

And now that we've gotten that little sermon out of the way, on to the methods for identifying your radio . . .

Look for a manufacturer and model number

The normal way to identify a radio is by manufacturer and model number (for example, "Zenith 7G605" or "Philco 42-350"). Model numbers can include any combination of letters and numbers, and they may be long or short, although most are from two to six characters in length.

There is no standardization whatsoever for model numbers. Every manufacturer was free to make up its own scheme, and often a given manufacturer would change its numbering scheme over the years. If you browse through our radio Gallery, you'll see plenty of diversity in these numbers.

Model numbers are often printed on a paper label attached to the back, inside, or bottom of the radio cabinet. The label usually contains other information, such as a serial number, tube diagram, or even a complete schematic diagram.

The model number may also be printed somewhere on the cabinet itself. On my Zenith TransOceanic H500, the number is printed in white ink inside the hinged back cover.

One exception to the no-rhyme-or-reason rule is the Philco company, who followed a very handy numbering scheme, at least for a while. If you see a Philco radio whose model number starts with two digits and a dash, the the first two digits indicate the year of manufacture. For example, my Philco 41-221 was made in 1941.

Many radios have a serial number in addition to a model number. Serial numbers are not useful for identification unless you have the company's manufacturing records, which are generally not available. (One exception is for Zenith radios. If you go to the Zenith Oracle website, you can look up a Zenith radio by its model number, serial number, or chassis number.)

Most radios list various patent numbers. These are also pretty useless for identification. Virtually all radio makers licensed several technology patents from other manufacturers, and they were required by law to disclose those patent licenses. That's why the patent numbers are shown. If you look at a bunch of old radios, you'll see that many of them list exactly the same patents.

Patent notices often include dates, but those do not tell you when the radio was made. They only indicate when the patent was originally granted, which could be many years earlier. So a patent date merely tells you that the radio could not have been made before that date.

Look for a name

Some radios have a name in addition to (or, occasionally, instead of) a model number. For instance, my Crosley F5-TWE was known as the "Musical Chef," and that name is actually printed on the front of its cabinet.

Hundreds of different names were used over the decades—everything from the predictable ("Globetrotter") to the alliterative (Zenith "Zenette") to the fanciful ("Phantom Baby").

The name may be handy if a collector guide happens to list your set by name instead of by model number. And, if you're communicating with other collectors, they may remember a name more readily than a number.

Where do I look?

Let's say that you've got the manufacturer and model number, and perhaps a name as well. The most readily available information sources are collector books and technical references, but there are other sources, too.

Collector books list thousands of radios, often with approximate values. Several are listed in Books for Radio Collectors, along with information on where to buy them. The Slusser (formerly Bunis) collector guide is one of the most popular, although it's by no means the only show in town. If you don't want to buy a collector guide just to look up one radio, perhaps your local library has a copy.

None of the collector guides lists every radio ever made, of course. For the reasons explained earlier, it's quite common to check the collector books and find that your radio is not listed.

If your radio does appear in a collector guide, you'll typically find the date when it was made, a photo or a brief description, and a guesstimate as to value. Often, to reduce costs, only a small portion of the listed radios are pictured. Specialized guides, such as the Hallicrafter's book by Chuck Dachis, may include a picture of every radio listed and give more detailed information.

If your specific model isn't listed in the guide, you may be able to guess something from similar model numbers. For example, if yours is a model Z123 (not listed), but the book lists models Z121, Z122, and Z124, all made in 1947, it's a reasonable guess that your radio was made in 1947. Similarly, if the maker of your radio went out of business in 1930, that's the latest year when your set could have been made.

Technical service publications are another great source of information. These include Rider's, Sams Photofacts, Most Needed Radio Diagrams, and so on. Technical references were published for radio repair shops and they are still to be found in many public libraries. Many radio collectors have personal copies, as well. In addition to technical data, such as schematics, these references will often tell you when your radio was made. You can find thousands of schematics for free download at Nostalgia Air.

Radio collectors may be able to help. If you haven't already done so, look for a radio collector club in your vicinity. The Antique Radio Classified website has an extensive list of clubs in North America.

Internet Forums. If there's no club nearby, you can contact an Internet forum or discussion group. Before posting your first question, look for a FAQ (frequently-asked questions) topic or "For New Members" link that explains which topics are deemed relevant in that forum. If you post an off-the-wall question in an inappropriate place, it may be ignored.

Websites. Another, rapidly growing source of information is websites like the one you're visiting now. When I launched this site in August, 1995, there was only one other website like it in the world. Now there are dozens, with more appearing all the time. A radio website might happen to show your radio, or perhaps its webmaster is willing to field your question. For example, the Radiomuseum site lists many thousands of radios, TVs, and phonos from around the world, and the the Radio Attic archive has several thousand (mostly American) radio photos. Our radio links page lists other favorite sites.

Speaking of which—if you've tried all these channels and struck out, feel free to send me some email. I usually have time to make a quick scan of my collector books to see if a radio is listed.

What if there's no name or model number?

Your radio may have lost its label, logo, or other identifying features. Or, perhaps it never had obvious identifiers to begin with. You can still identify the set, although it may take some detective work. Here are some things to look at:

  • Component markings. If the outside lacks identifiers, the inside may still hold clues. Look inside the chassis—if you see the same manufacturer's name stamped on all the tubes and other components, that's a tipoff. On the other hand, it's not unusual to see a mixture of brand names on components. Many manufacturers got components from other suppliers. And radios that were repaired over the years often have a random assortment of replacement parts under the hood.

  • Cabinet design. Often a strong indicator of when a radio was made. The very earliest radios were typically bare components mounted on a board. Somewhat later, many were housed in comparatively plain wooden or metal boxes. By the late 1920s, some were housed in elaborate cabinets designed to look like "real furniture" instead of electronic gear. Cathedral and tombstone style wooden cabinets were most popular during the 1930s. The 1940s were the heyday of "Machine Age" and other design trends. And there were brief fads for certain design elements such as mirrored glass cabinets or tuners shaped like rotary telephone dials.

  • Cabinet materials. 1920s radios were typically housed in wood. although some tabletops came in rather plain metal cabinets. Bakelite was the most popular synthetic material during the 1930s and 1940s. Other early plastics, such as Plaskon and Beetle, predated the flood of new synthetics that came along during the 1950s. Wooden cabinets were used during all periods from the 1920s to the present. Most wooden cabinets were covered with veneer and the vast majority of them were finished in lacquer.

  • Dial Markings. The band and frequency markings on the dial can tell you something about a radio's age. The earliest 1920s radios did not show any station numbers; instead, their knobs were marked with numbers from 0-100 or sometimes nothing at all. If your radio has a band marked Police or Aircraft, it was probably made before World War II; those frequencies are no longer used for such communications. Shortwave radio was common from early days, but FM broadcasting wasn't developed until the 1930s. The FM band frequencies were changed after World War II, so if you have a radio that tunes FM from 42-50 megahertz rather than the modern 88-108 megahertz band, you know it was manufactured before 1942. A radio that has FM stereo was made in the late 1950s at the earliest. Conelrad (CD) markings on the AM dial at 640 and 1240 kilohertz indicate that the radio was made between 1953 and 1963.

  • Tubes. Tube types changed over the years. The very oldest tubes looked more like light bulbs and had screw-type connections. Most 1920s tubes had glass envelopes and large bakelite bases with four or five pins. 1930s and 1940s tubes typically had glass or metal envelopes and six, seven, or eight pins. Locking ("loktal") metal bases were used for a few years in the late 1940s. They were superseded in the 1950s by all-glass "miniature" tubes with very thin pins. Keep in mind that different tube types overlapped. For example, some radios continued to use loktal or older tube types into the 1950s. However, if your radio uses glass miniature tubes, you know it must have been made after the end of World War II, and was likely made in the 1950s or later.

  • Transistors. Transistors were introduced in 1957, so every transistor radio is dated after that time. Transistors didn't become common until the 1960s.

You may need to be creative to identify your radio through these means. There is no single place to find all this diverse information, but the quest can be an enjoyable pastime in itself. In search of facts, some collectors have gone to great lengths, dredging up forgotten company records or locating and interviewing ex-employees of long-vanished companies.

©1995-2014 Philip I. Nelson, all rights reserved