Regency TR-1 Transistor Radio Facts and Figures

" See it ! Hear it ! Get it ! "
That's what an original Regency advertisement said about the TR-1. Why?

Because, in 1954 it was the world's " first pocket radio " (Holiday magazine, June, 1955, p.123).

Introduction
There's an allure to the Regency TR-1 transistor radio that can't be denied. It was the first (widely embraced) transistorized consumer product, had beautiful and daring styling for the time (styling that still holds up, in my opinion), and further demonstrated the significance of engineering and technology in the 20th century. The story is one of American ingenuity and business daring. And the coincidence of the radio's introduction and the emergence of rock and roll music in the same year is fascinating. The TR-1 is a true collector's prize.

If you're only looking for repair info, see my separate repair page.

The BBC (British Broadcasting Corporation) in London called me for an interview a few days prior to the Oct. 18, 2004 50th anniversary of the announcement of the TR-1. It ran on BBC on Oct 18 at various times -- I caught it at 0515 GMT. It's a 1.0 MB mp3 file. It was conducted over an ISDN digital line (two 56k mpeg2 links) between a local radio studio in Milwaukee, Wisconsin, and BBC studios in London, England.

I have obtained the long lost film of the Regency TR-1 factory, circa 1955. Here are some VIDEO clips of the factory operations. The whole 3 minute film is available here. See the TR-1 actually being built. INCREDIBLE !

And some people believe that the TR-1 looks somewhat like another "popular electronic device!" By the way, after this mention my site received 798,000 hits in the next 36 hours (at peak it was about 20 hits per second) !

If you're of a certain age you'll surely remember the 1960's music group, the Byrds, with lead guitarist/vocalist Roger McGuinn. But did you know that nowadays he collects transistor radios, and has a treasured Regency TR-1G? I think I spotted a red TR-4 on his shelf too. How cool is that?

Invention & Technology magazine has a wonderful article on the TR-1 in their Fall 2004 issue. I supplied the photos! (Link to the text-only version). They give lots of background on the radio and tell the story of its development. They show some of the radios from my collection, including the insides of one. Good stuff! The author, Bob Simcoe, was interviewed on National Public Radio on Nov. 5, 2004 at 2040 GMT. Here's the 2.1 MB interview (mp3 file). Very interesting!

Here are some nice photos of several extremely rare pearlescent TR-1s, suitable for Windows background (wallpaper): Meridian blue, pearl white, and lavender. And, the highly unusual "Clearback" TR-1 (offered to dealers).

And here's a fun photo of LOTS of radios together.

There's almost always something new showing up on this site. Be sure to hit Reload or Refresh with each visit (and look for the

icon). Do you have any comments or suggestions? Send 'em along to me, Dr. Steve Reyer. Thanks, and enjoy.

Quick Facts
The Regency TR-1 was the first commercially-sold transistor radio, and was the first widely sold transistorized product. It was designed and manufactured in the United States (no, not Japan) for just one year starting in Nov., 1954. About 100,000 were sold that year at $49.95. Here's a closeup, and a view of the insides. (Somewhat similar-looking, but different, radios produced later are the TR-1G and the TR-4). Now for the details ...

History
The book Crystal Fire describes Texas Instruments, Inc. of Dallas, TX, (Proc. IRE, June, 1955, p.162A) in the early 1950s as especially interested in finding a wide market for their newest device, the transistor. While the transistor (the component, not the radio) was invented several years earlier at Bell Telephone Laboratories in the USA, the non-military application for the sometimes quirky device was limited to the narrow hearing aid market. By this time, the original point-contact transistor was generally superceded by the more easily manufactured junction transistor. The transistor's inventors, Shockley (seated), Bardeen (glasses) and Brattain, would forever be famous for their work on this miracle component, winning a Nobel Prize on November 1, 1956 (NY Times, Nov. 2, 1956, p.1). (note: the book Crystal Fire describes the invention of the transistor, the physics, etc., and has only a few pages on the TR-1).

(Bell Labs had officially announced the invention (and demonstrated a "transistor radio") on June 30, 1948, with the New York Times carrying the news in their entertainment-oriented "The News of Radio" column on July 1, 1948 (p.46, see blue outlined section). It wasn't long before experimenters would present their own circuits for the public to try (this is possibly the first published "do-it-yourself" article, and uses a point-contact transistor, the Raytheon CK-703): page 1, 2, and 3 (Radio & Television News, January, 1950, p.38). Here's one of the first advertisements for the transistor itself (QST, March, 1953, p.97). For more information on the history of the transistor (component), visit my good friend Bob McGarrah's transistor history/museum site).

A Transistorized Radio
In 1954, Texas Instruments approached RCA (and other noteworthy radio manufacturers of the era), but they expressed little interest in selling transistor (or "transistorized") radios. However, a small Indianapolis company, the Regency Division of Industrial Development Engineering Associates (I.D.E.A., at 7900 Pendleton Pike, Indianapolis 26, Indiana, telephone: CHerry 2466) was especially interested (How the factory looked in 1990 -- thanks to Don Pies). (The factory building is presently occupied by an unrelated company (2004 photo)). Prior to this (Electronics, January, 1953, p.353), they had been manufacturing television UHF converters, signal boosters, filters (QST, Nov., 1953, p.113), and (around then) hi-fi gear (High Fidelity, June, 1955, p.19). By June, 1954, an agreement had been reached on the venture. It was to utilize four Texas Instruments "grown-junction" germanium (not silicon) transistors (even though a TI ad in the December, 1954, Electronic Design mentioned "high volume production" of the superior (but probably expensive) silicon type).

A TI information bulletin on October 18, 1954 announced the innovative radio -- the first of its kind. The radio was designed to receive AM broadcasts only, as FM was not yet a contender. It would include, ultimately, just four transistors, in a superheterodyne design. The transistors cost around $2.50 each, approximately $20.00 in today's dollars -- leaving just a small profit margin in the radio. The radio sold for $49.95, or nearly $400.00 of today's dollars -- a large sum, but they still sold very well.

Years later, Regency was still concerned with technological developments, as demonstrated in this interesting letter that recently surfaced. Note the logo, address, and phone number from 1961, as well as their name change about to occur. Regency eventually evolved into Relm Wireless Corporation, makers of two-way radio equipment. Their 2001 Annual Report featured the Regency TR-1 on the cover!

Design of the Regency TR-1
(Also see Don Pies' site, "TR-1 Transistor Radio Historical References").

The inventor of the TR-1, Richard C. Koch (pronounced "coke"), patented certain features of the design and assigned the patent to I.D.E.A. (a common practice in industry). The patent (2,892,931) also included the schematic diagram as a typical embodiment of the design. Here are the four pages of the patent, which was applied for on March 25, 1955, but not granted until 1959: cover page, page 2, main schematic, sub schematic. Other patents applied for in 1955 but not granted until 1958 and 1959 were on the chassis construction (2,820,890) and on a specific circuit technique (2,880,312). The above are "utility" patents affording protection to inventions by Richard Koch. The company that designed the case (Painter, Teague and Petertil , of Chicago, IL) was awarded a "design" patent on the case's appearance (Des. 176,480) in December, 1955. This patent (awarded solely to Victor Petertil) was also assigned to I.D.E.A. Amazingly, Victor Petertil also holds the very next sequential patent (Des. 176,481), for a very similar pocket radio. Perhaps Regency chose between these two case designs. Could the TR-1 have looked like this instead?

The TR-1 came in four colors, initially -- black, cloud gray, mandarin red and ivory (or bone white). Subsequent uncommon colors were marbleized: olive (or forest or jade) green (with white marbeling), and (mottled) mahogany (with black marbeling). Extremely rare colors are the pearlescents (sometimes called "translucents"): lavender, pearl white, meridian blue (or turquoise), (shell) pink, and lime. And a late version of a Regency fold-out card mentions "orchid" (which may actually be lavender). One collector has reported owning, at one time, the lime radio; I have never seen one myself. The pearlescent lime TR-1 photo shown was contributed by another collector (one who does not own a lime TR-1), having seen this radio on eBay around 1999). Note that, as manufactured, the TR-1 volume control knob color matches the case color.

Was there a clear TR-1? Well, yes and no. As far as I can tell, there never was one marketed to the public, but some special clear cases were produced for demonstration purposes by TI or Regency personnel. Take a look at the front and back of this one (from the Smithsonian Institution). This is strange -- it has a TR-1G serial number, but a TR-1 tuning dial, and the case back seems to have the early TR-1 "dimple" to accomodate the tuning capacitor setscrew. So, it's all a little unclear. And here's another one that's in a private collection: front and back. Note the unusual lack of a serial number. Dealers were offered a "Clearback" option, to "...make a fascinating point-of-sale display that closes many sales! Order from your distributor." The clear and clearback radios are extremely rare. [Photo of pink TR-1 courtesy of Eric Wrobbel, from his fine booklet "American Shirt-Pocket Transistor Radios." Also, be sure to see his great color booklet on the Regency TR-1.].

Occasionally other unusual case types appear -- for example one that is chrome plated. Whether this was produced at the factory or by an owner is uncertain, but it is believed that more than one does exist. And here are a white and a blue pearlescent with what appear to be rhinestones in between the speaker grille holes. Was this from the factory? A very unusual item is this Texas Instruments prototype radio, also in a clear case -- reportedly one of the first engineering prototypes of the TR-1 (and with a tuning knob from an Emerson 747 subminiature-tube set).

The logo on the radio varied with time, appearing in three different styles. The early logos were heavily molded into the case, then filled with gold-colored paint, leaving deep impressions that survived through years of use. The middle logo was hot-foil stamped onto the case leaving just slight impressions. It had a short crown. The late logo was also foil stamped, but with a taller crown, somewhat closer to the early logo. The foil logos were not as sturdy as the molded one, and many radios have this partially, or in some unfortunate cases totally, worn off. Radios with the molded logo also seem to have the extra tuning mark below the tuning dial, while later radios with the foil logo have just one tuning mark above the dial. The dot under the volume control has been seen on both molded logo radios and on foil logo radios. Some collectors believe the logo was converted to foil to allow other brand names to be affixed to the plastic case, as in this Bulova 250 example. Others believe this was simply a cost-saving measure during the evolution of the radio from the TR-1 to the TR-1G.

The volume control knob appears in several subtly-different forms. One has a small square area that faces out when the radio is turned off. One other version has a gold dot in this square area. And sometimes the volume control has no square area at all.

Another interesting front panel item concerns the tuning dial. In the Regency brochure, and in many magazine portrayals of the radio, the numbers on the tuning dial increase clockwise. However, all known manufactured radios have the numbers labeled the other way around. Most of those magazine shots appear to be artists' renderings of how the radio might look. But this one, on the cover of the Proceedings of the IRE, Dec. 1954, appears to be an actual radio, with the numbers reversed. Hard to tell, but the reflections on the table make it appear to be a real, 3-dimensional object. The dial has red, triangular, CONELRAD (CONtrol of ELectromagnetic RADiation) Civil Defense (CD) markers at 640 and 1240 kHz. This was the predecessor to the Emergency Broadcast System.

Recently discovered is the news that Regency changed the TR-1 circuit after serial number 105,500 (near the end of production). This is described in the Sams Photofact Production Changes Bulletin 155, dated "5-56" (May, 1956), in Sams Set 317, Folder 1. A resistor was changed, a new one added near transistor X1, and a "pi (filter) network" consisting of two capacitors and a resistor was constructed using an existing capacitor, and a new resistor and capacitor. This is located after the diode detector. Here are the details (an edited version of pages 1 and 3 of the Bulletin). The reversed direction of the diode (compared to the original schematic diagram) is most likely a "typo." Here's an example where the 100-ohm resistor was "tacked on." Note the extra resistor and capacitor on the new board and the new resistor (circled) near X1.

Batteries
Advertisements said the radio measured 3" x 5" x 1.25", weighed 12 ounces, and used a "standard" 22.5 volt battery (originally for tube-type hearing aids). This battery, an Eveready 412 (NEDA 215), is still available (see below). Another possibility is an Eveready 505 (NEDA 221). Here's an older Eveready 505E "B" battery, the Burgess U15 battery as specified on the TR-1 label, and the actual, original, Regency 215 battery ($1.25). Here's a detailed look at the label on a Regency 215 battery. An uncommon accessory was this Battery Saver Kit ($6.25) that held five batteries in a vinyl pouch. The instructions describe a means for cycling the batteries to maximize their life. (Does this really work? Read more here). The batteries are still available, at stores like Radio Shack and Batteries Plus.

Accessories
Back in the '50s, when you visited your local shop to see the TR-1, they could give you a promotional fold-out card, the same size as the radio, to inspire your future purchase (there were two other versions of the card, an interim one, and a late one ). Finally, when you actually bought one, it came with a small user's guide. There were also an interim, and a late version of this. too, with the latter being after the coin slot was introduced. The radio came packed in either an early or late style cardboard box (with the color stamped on the end). It may have been protected by this corrugated paper packing material (note the round indentation from the tuning dial), or with a sheet of tissue paper. Sometimes the store display featured this eye-catching card, or this one. There were also early (left) and late (right) style leather cases (Model "LC-1", at extra cost -- $3.95, and in their own shipping box). An optional earphone (Model E.P.-1) was $7.50. It came packed in either of two ways. I believe the first (earliest) was a simple cardboard box with a printed instruction sheet. The second packaging was in a plastic carrying case, inside a small cardboard box.

At some point, Regency used this store display to feature its radios. It's not clear during what year these appeared. Window display cards include this pleasant "Music Break" item, and this more sophisticated "male and female hand", promoted to dealers in this cheesecake publicity photo (Radio & Television News, May, 1955, pp. 117-118). Early press release information indicates the TR-1 was first introduced in New York and Los Angeles.

When the TR-1 was shipped to dealers, it may have been in a carton like this one (the one shown was actually used for shipping TR-1G radios).

The Manufacture of the TR-1
The TR-1 was manufactured at Regency's plant starting on October 25, after being announced on October 18, and distributed starting November 1, all in 1954 (NY Times, Oct. 18, 1954, p.35). The price was $49.95 for the non-pearlescent colors (the pearlescents sold for $54.95). As mentioned above, the parts used in the TR-1 came from Texas Instruments in Dallas, TX (transistors and transformer (Electronics, Feb., 1955, p.204)), capacitors from "Nashville" (generally the four electrolytic capacitors), Erie Electronics in Erie, PA (Electronics, June, 1955, p.220) and Centralab (Globe Union) of Milwaukee, WI (Electronics, May, 1955, p.237), speaker from Jensen of Chicago, IL (Electronics, March, 1955, p.338), IF transformers from Vokar of Dexter, MI (Electronics, Feb., 1955, p.375, and April, 1955, p.335)), volume control from Chicago Telephone Supply of Elkhart, IN (Proc. IRE, Feb., 1955, p.25A), and the tuning capacitor from "R/C" or Radio Condenser Co. in Camden, NJ (Electronics, Sept., 1955, p.225). There were either of two germanium diodes used in the detector, the silvery TS117 (Tungsol) or the red CK706A (Raytheon). The plastic case was produced by Argus Plastics of Indianapolis, IN (the logo appears inside the case front).

And who made the printed circuit board? An advertisement (Electrical Manufacturing, Sept., 1955, p.291) for The Richardson Company of Melrose Park, IL (and Indianapolis, IN) says that they supplied the printed circuit board material to Croname, Inc. of Chicago, IL, and that Croname made the boards for Regency, according to Regency's design. The board pictured in the ad appears the same as an actual TR-1 board, and the radio is a TR-1. However, a later ad for the Continental Diamond Fibre Division of the Budd Company, Inc. (Electrical Manufacturing, May, 1956, p. 48) shows a TR-1 and states that they supplied the board material to Insulated Circuits, Inc. of West Caldwell, NJ, for the manufacture of the board. The radio shown is certainly a TR-1, but the board's foil traces appear slightly different. I don't have a TR-1G to compare, but I wonder if the "Insulated Circuits" board is for that radio. For the TR-1 I'll go with the first board -- the Croname, Inc. board, shown in the first ad.

There exists (and has since at least July, 1955) a Sams Photofact set of repair instructions (Set 283, Folder 10)

The 4-page package: 1, 2, 3, 4 that I have (with the original 7-55 date) includes a procedure for "aligning" the receiver, and a complete list of parts with component values, parts placement diagrams, and an annotated schematic, showing various voltages at selected points. Another good description of the various circuit subsystems and components is on pages 151-155 of: Kiver, Milton S., Transistors in Radio and Television, McGraw-Hill, 1956: Here are pages: 1, 2, 3.

Here's what appears to be a "cutsheet" supplied by Regency to either wholesalers or retailers: Front and Back. Interesting that they mention a "complete merchandising kit." I wonder what was in that.

Here's a photo of the inside of my gray TR-1 with the components labeled. It might be helpful in case you're going to experiment with yours. This parts location diagram will be helpful too. Some people like to refurbish their TR-1s in an attempt to get them working. They sometimes replace dried out electrolytic capacitors, old transistors, etc. I prefer to keep mine "as manufactured." In any event, the photo is fun to look at. Printed circuit boards were not too common at the time, with many other radios built with point-to-point wiring. The TR-1 printed circuit board is one-sided (foil traces on one side only). Here are views from the component side and the foil side of the board. But if you're planning on repairing yours, read my experiences about it.

In the News
Early announcements of the radio appeared in many publications, such as the New York Times (Oct. 18, 1954, p.35), the Wall Street Journal (Oct. 19, 1954, p.8), Business Week (Oct. 23, 1954, p.114) and Time Magazine (Oct. 25, 1954, p.71). Around the same time Popular Mechanics magazine (Jan., 1955, p.159), in their announcement of the radio, printed the schematic too.

Consumer Reports had a one-page review in April, 1955 (p.171). In using disparaging phrases such as "toy-like novelty" and "has made use of the transistor's small size, but...offers no other advantages" in comparing it to tube sets, they rain on an otherwise revolutionary parade, and rather miss the point. Their comparison of two transistor and one hybrid (a transistor and tube combination) radios in July, 1955 (p.305) panned the TR-1 again. Most listeners would probably agree that the also-ran Raytheon 8-TP (at a whopping $79.95, approximately $600 today) sounded better. With 8 transistors and a larger speaker, it should, and did. But the smaller form factor of radios like the TR-1 was irresistable, and would be here to stay. In time, small radios would supply much of the performance of the larger sets, at least in terms of sensitivity and selectivity, although they would almost always compromise tone quality. Another review, somewhat more favorable, appeared in the same month in Consumers' Research Bulletin (July, 1955, p.29).

It was also featured in PF Reporter (page 1,and page 2), for January, 1955, after first being mentioned in an editorial in Nov., 1954. This was a Sams periodical directed toward the radio/TV repair business (note: PF=PhotoFact). In March, 1955, they had complete repair and troubleshooting instructions (pp. 11, 52-57). See pages 1, 2, 3, 4, 5. And the industry publication Electronic Design had a nice article on the TR-1 in their December, 1954 issue (pp. 20-21), and mentioned the Texas Instruments transistor part numbers: TI223 for the mixer/oscillator, TI222 in the two IF stages, and TI210 in the audio stage (here's an ad from Electronics, Nov., 1953, for a similar transistor). The germanium transistors were manufactured as the "grown junction" type, starting with huge crystals produced in this TI laboratory (Automation, Nov., 1955, pp.48-53). A short, but complete, account appeared in Radio & Television News (Jan., 1955, p.54) and another in Radio-Electronics: pages 1, and 2 (Aug., 1956, pp.39-40). It was quite the novelty at the time, as evidenced in this review in High Fidelity magazine (June, 1955, p.102). Other mentions were in Science and Mechanics, Feb., 1955, p.115, and Popular Electronics, Jan., 1955, p.100. It was also shown on the cover of Audiocraft magazine, as late as April, 1956, and in June, 1957 on the cover of Popular Electronics.

The actual factory Service Manual is a close match to the PF Reporter repair instructions mentioned above. But it's worth seeing, for sure. Here are pages 1, 2, 3, 4, 5, 6, 7, 8.

A good review article also appeared in the December 1985 (pp.64-69) IEEE Spectrum (IEEE=Institute of Electrical and Electronics Engineers). Here are pages 1, 2, 3, 4, 5, 6. (Note the missing antenna and capacitors next to the battery on page 2). It's interesting to note that the radio was originally mentioned in the predecessor organization's journal, the Proceedings of the IRE (Institute of Radio Engineers) back in the December, 1954 issue (p.116A) and featured on the cover.

A very interesting account of the breadboard development of the radio at Texas Instruments, prior to redesign and manufacture in cooperation with Regency, appears in the Southwestern Historical Quarterly, July 1, 1993, v.97, n.1, pp.56-80. Only one page of the huge article is reproduced here, but see this complete text-format version of the article. It describes the day-by-day and circuit-by-circuit account of the original work, undertaken to determine feasibility. Head people at TI (Patrick Haggerty, mentioned in several of the above articles) and Regency (Edward Tudor) are shown here in a classic photo (see caption). Edward Tudor died in 1989 and is buried in Murphysboro, Illinois.

Around the year 2000, the United States Postal Service issued this unusual collector's disk, showing the TR-1.

Advertisements
Some local advertisements featured the TR-1 too, such as this sophisticated one from Chicago (Sports Illustrated, June 6, 1955, p.13), another Chicago ad (Sports Illus., June 6, 1955, p.68), and this slightly unusual one from Seattle. Many ads appeared in the New York Times newspaper. This may have been the earliest, on Nov. 21, 1954 (p.77), just three weeks after the radio's distribution. Here are some more from 1954 and 1955. Of these, the first to mention the pearlescent colors was on Dec. 2, 1955 (p.20). Liberty Music Shops was also running ads in New Yorker magazine. Here are ads from Dec. 3, 1955 , p.210, and from Dec. 10, 1955 , p.177. At Christmas, 1956, the TR-1G and TR-1 (and other Regency radios) were offered for sale, with the TR-1G being $10 cheaper. The TR-1 colors, at that time, were referred to as "Stardust Colors" in one ad from the New York distributor (New York Times, Dec. 11, 1956, p.14).

Celebrity Connection
The TR-1 was also connected to some well-known people in two separate ways. First, IBM president Thomas J. Watson Jr. gave out TR-1s to his staff, reminding them that they had not yet produced a transistorized computer, while a much smaller company had no trouble making radios that way. And second, Hollywood movie mogul (and at one time husband of actress Elizabeth Taylor) Michael (Mike) Todd gave out the radio as gifts to commemorate his movie "Around the World in 80 Days." They were housed in book-like cases, as shown here in an prime example of 1950s sophistication with British actor Trevor Howard (who was in the movie). Some of these "Mike Todd" models, in various colors, still exist, including (it is believed) the gifts given to Arthur Miller, Shirley MacLaine, Lou Berg, Bill Shawn and Ted Patrick. The "80 Days" "book" case is very rare.

If you're of a certain age you'll surely remember the 1960's music group, the Byrds, with lead guitarist/vocalist Roger McGuinn. But did you know that nowadays he collects transistor radios, and has a treasured Regency TR-1G? I think I spotted a red TR-4 on his shelf too. How cool is that?

Collectors Items
How many of the original radios still exist is an open question. They command a significant price at auction, depending on their condition and the rarity of their color. How many were made? Some sources say around 100,000. The latest serial number I've seen is around 140,000, and the latest capacitor date code appeared to be 601 in an unclear photo (week 1, 1956). More certain is cap code "543" (week 43 of 1955), approximately one year beyond the earliest cap code I've seen, "445" (week 45 of 1954). Manufacture dates seem to be visible on some later transistors, too, with their dates running between 2 and 11 weeks later (that is, the transistors were manufactured months after the capacitor, in some cases). For example, my red radio has a cap code of "528", but the transistors appear to have date codes of "539" -- 11 weeks later. Here's a "517" code on a transistor in my green radio.

S.T. Harris, former Vice President of Marketing for Texas Instruments, speaking at the "25th Anniversary Observance -- Transistor Radio and Silicon Transistor" meeting, on March 17, 1980, stated that "by January 1, 1955, we had shipped 1500 units" and "by April '55, 32000 units had been shipped." He also said "Total units manufactured were...a little over 100,000." At the same meeting, Patrick Haggerty, former Executive Vice President of TI stated there were "roughly 104,000 to 105,000 units" manufactured over "the 12 or 15 months of the cycle." Here are some excerpts from the report of that meeting: pages 1, 2, 3, 4, 5, 6.

Many of the surviving TR-1s have cracks or broken corners, probably due to trouble opening the radio. There are ridges in the front case that mate with notches on the back case. Here's the technique I use for opening the case, safely. Here's another approach that may work. Even tight cases seem to open easily using these methods (no guarantees). Another common problem with well-used TR-1s is that the volume control dial, and the case opening for it, tend to get worn. I have no good solutions for that.

Another "problem" is that the back often has a "ding" along the edge. After I spotted this on more than one radio, I made a comparison. It now appears that the "ding", which is 2 inches down from the top of the radio, was caused by the plastic molding process. Look at this comparison of five different case backs, aligned electronically, and see what you think.

Regency also produced some specialty-label radios based on the TR-1 design, such as the Bulova 250 in several styles and colors (note the similarity of the chassis, except for the missing earphone jack, although the earphone jack bracket is there!) and the Mitchell 1101 (or 1102, 1103). Related later models are the Regency TR-1G (1956, known colors are black, coral, yellow, gray and turquoise) and the 9-volt-powered Regency TR-4 (1957, known colors are black, ivory and red). The inside of the TR-1G and the inside of the TR-4 both look a lot like a TR-1. Another close match to the TR-4 is the Mantola M4D.

Repairing a TR-1 -- It Can Be Done
When I bought my ivory TR-1, I discovered that while it didn't work (no surprise), someone had repaired it in the past. I was able to get it running after not too much effort. It plays great! Here's the story.

Differences
There are many slight differences in construction of the radios. I have seen different wiring of the volume control, battery clips, capacitors next to the clips, serial numbers (obviously), 3-digit date codes on the tuning capacitor, etc. I also found two different types of on-off switch construction, although not correlated with serial number. Intrigued, I followed the radios on eBay, not necessarily to bid on them (sometimes I couldn't resist), but to note the similarities and differences, detailing all that I was finding (also see the expanded version of this table).

Serial	Color	Cap code	Elec. caps	Batt clip	Coin slot	Label	Vol dot	Tune marks	Vol solder lug
19675	Black	447	Brown	Straight	No	Small	No	Both	Wire
21852	Ivory	445	Brown	Straight	No	Both	No	Both	Wire
30154	Pearlescent White	445	Brown	Straight	No	Small	No	Both	Wire
30309	Pearlescent Lavender	447	Brown	Straight	No	Small	No	Both	Wire
49118	Clearback / Gray	Repair	White	Folded	Yes	none	Yes	Top	Wire
58298	Green	515	Brown	Straight	No	Large	No	Both	Wire
60967	Pearlescent Blue	505	Brown	Straight	No	Large	No	Both	Jack
62613	Gray	515	Both	Straight	Yes	Large	Yes	Top	Jack
83145	Mahogany	526	Brown	Folded	Yes	Large	Yes	Both	Jack
99100	Red	528	Brown	Folded	Yes	Large	Yes	Top	Jack

An explanation of each table feature is given below.

Serial number
Appears on the label under the battery. I believe they started at #1001. How high did this go? Which numbers in which months? Actually, there is somewhat of a correlation between the date of manufacture of the tuning capacitor and the serial number on the radio, when viewed graphically.

Color
As mentioned above, colors were black, ivory, red, gray, green, mahogany, and the pearlescents: white, blue, and pink.

Cap code (date)
On the tuning capacitor is a three digit code ("522" is shown in the photo) indicating the date of manufacture of the capacitor. For example "543" means the 43rd week of 1955. The "522" example means the 22nd week of 1955. If the radio was sent in for repair, Regency would apply a repair tag to the tuning capacitor, obscuring the date code. Note, too, that some radios had a setscrew holding the capacitor shaft, and some did not. The setscrew seemed to disappear around serial number 75000 (approximately cap code "526" and beyond). Early models had an indentation (to the right of the label) ground into the case back to allow clearance for the setscrew. It was obscured if the radio had a large label.

Elec. caps
Next to each battery clip is an electrolytic capacitor. Some are brown, and some are white. It may even be possible to create your own authentic-looking electrolytic replacement capacitors. Take this original "Nashville" wrapper and wrap it around a new, replacement cap. It's not perfect, but it may be worth a try.

Batt clip
Some radios have a folded metal battery clip and some have a simple straight piece of metal.

Coin slot
Does your plastic case have a coin slot for opening the case?

Label
The paper label inside the back cover came in either a large or small size. My gray one has both! (One over the other). And then there's this unusual "dual-purpose" label, for the "TR-1 & TR-1G", that's in my ivory TR-1 (pasted over an original small label). Apparently some repaired radios received this one during repair. The latest patent referenced is from June 30, 1959, seeming to indicate my ivory radio was repaired sometime after that. Here's a large version of the large label -- actual dimensions are 4.10" x 2.44" (104 x 62 mm).

Vol dot
Some radios have an embossed dot under the volume control indicating "off." Some do not.

Tune marks
There is a vertical mark above the tuning dial to indicate what station is being heard. Some radios also have a tune mark below the tuning dial.

Vol solder lug
On some radios, the volume control solder lug closest to the edge of the radio is soldered to a wire. On some it's soldered to the earphone bracket.

Speaker
Some speakers are labeled "Jensen" and some are labeled only with numbers.

If you have any suggestions (corrections?) or just comments,
please send them along to me, Steve Reyer.
I'd like to hear from you!