Radio Boulevard
Western Historic Radio Museum


WHRM Radio Photo Gallery


- Roaring 20s Radios -

Battery Sets, Crystal Sets and Early AC Sets

1922 to 1929




Photo right:   Let's face it. Radio wouldn't have been "RADIO" without these guys. Center is Guglielmo Marconi. Left is Owen Young, board chairman of RCA, on the right is Ed Nally Jr., president of RCA. Owen Young, originally from GE, was instrumental in forming RCA from GE radio assets and with the acquisition of American Marconi in 1919. Ed Nally Jr. was former vice president of American Marconi and became the new president of RCA. RCA was officially created in November, 1919. This photo was taken on board Marconi's yacht, the "Elettra."   photo: Radio Journal, Sept. 1922


Battery Sets  - 1922 to 1927


Westinghouse for RCA


Westinghouse cross-licensed with GE/RCA in 1920, offering the Superheterodyne patent and the Regenerative Detector patent as their end of the agreement. Commercial Radio Broadcasting was about to start with Westinghouse's KDKA radio station located in Pittsburgh, Pennsylvania going on the air in November 1920. The first radio offered to the public for listening to the new broadcasts from KDKA was some gear that Westinghouse had built for ham market (radio amateurs.) The hams were less than enthusiastic about the RA and DA sets as ham receivers. So, lucky for Westinghouse, here was a new market for these sets - the Broadcast Radio listeners. These neophyte-listeners weren't nearly as critical as the hams were and the RA and the DA sold quite well. By mid-1921, Westinghouse had combined the RA-DA into one cabinet and designated this model the RC. The RC was produced well into 1922. Westinghouse also offered an Antenna Tuner (RT) and an RF amplifier (AR) in matching boxes, that is, matching the RA-DA.

The circuit uses three 1A pure tungsten filament tubes, a UV-200 soft detector and two UV-201 hard amplifiers. Early versions of the DA used WR-21 or similar tubes since the UV-200 and UV-201 weren't available until late-1921. Regeneration is via a tap switch (Tickler.) Performance is dependent on how good the tubes are. Pure tungsten filament tubes can't be rejuvenated and when the tungsten is exhausted of its ability to emit electrons, the tubes no longer function (even though they will "light up.") With good emission tubes the RC will perform adequately but it isn't very selective. This is due to the single-circuit tuner used. The addition of the RT and the AR improve selectivity and over-all performance. However, this "component" approach, while popular with enthusiasts, didn't appeal to the regular Broadcast listeners.  


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Westinghouse for RCA

Radiola Grand - Model RG

The Radiola Grand was the deluxe radio receiver from RCA-Westinghouse for 1923. Designed to replace the unsuccessful Aeriola Grand (with its ballast tubes and strange circuit adjustments - one had to pull tubes to lower the volume!), the Model RG was a great performer and its gold-plated hardware gave it that impressive, expensive look. At $325.00 in 1923 - it WAS expensive! Using four WD-11s, the circuit is a regenerative detector with single AF driver and Push-Pull output. Interstage transformers are used for coupling. Sound quality is excellent (for a battery set) using the built-in horn speaker. Note on the grille cloth: Originally RGs did not have grille cloth, however this brocade cloth was probably installed by the first owner or perhaps the dealer. Also, two styles of grilles were produced. The type shown is the later version grille.

The cross-licensing agreement with Westinghouse and General Electric (along with Wireless Specialty Apparatus, AT & T and RCA) was going to have GE provided 60% of the radios that RCA could sell. Westinghouse and WSA provided the remaining 40%. However, it took awhile for GE to get up to speed and most of the 1921, 1922 and 1923 radios were actually from Westinghouse. GE only provided the Radiola V and a few other models that were actually old shipboard radios that GE converted to look like consumer radios. Although GE had created RCA with their own assets and with the purchase of American Marconi (Oct. 1919,) GE decided to keep the American Marconi plant in New Jersey for themselves rather than let RCA build their own radios. This kept RCA under GE control, along with help from Westinghouse, throughout the 1920s. RCA didn't build any of their own gear (except for Radiomarine Corp of America shipboard radios that were built at the WSA plant) throughout most of the 1920s. Things changed in the late-1920s with RCA acquiring many of their own patents and finally with their purchase of the Victor Talking Machine Company (purchased with the financial help of GE and Westinghouse in 1929.)


Westinghouse for RCA

Radiola Senior Regenerative Receiver - Type RF

 Radiola A.C. 2 Stage Audio Amplifier - Type AC

The very popular, single tube receiver,  Aeriola Senior, was introduced in late 1921 for $65. By late 1922, it had been updated with a bakelite panel and mahogany box. Still later, in 1923, the name was changed to Radiola Senior (price was still $65.) A two-stage AF amplifier was an accessory to the Aeriola Sr. and also to the later Radiola Sr., also priced at $65. The 2-Stage Audio Amplifier added enough audio gain that a horn speaker could be used on most of the stronger signals, thus allowing the entire family to enjoy "the radio." The Aeriola and Radiola single tube, regenerative receivers perform quite well and are easy to operate requiring only a single 1.5vdc dry cell and a 22.5vdc B+ battery, a set of earphones and a suitable antenna and ground. The tube normally used is a WD-11, however an 864 or WE239A will work equally well but will require the use of a socket adapter (WE-239A is shown installed.) The AF Amplifier requires two WD-11 (or compatible substitutes) along with a set of dry cells for the filaments and a 60 to 90vdc B+ battery. The amplifier is shown with later type WD-11 tubes installed. The horn speaker was optional.


Federal Telephone and Telegraph Co.

DX Type-58

Federal built high quality receivers though some of their circuits and mechanical devices seem rather "Rube Goldberg" at times. The DX Type-58, from late 1922, was designed for the enthusiast and the metal cabinet seems to show this. Selling price was somewhat expensive for a four tube set - $123. Federal's workmanship was excellent, however their documentation is vague at best. It is interesting that Federal was so afraid of a RCA-Westinghouse law suit over the Regenerative Detector patent, they didn't tell owners (in their instruction manuals) that their radios could be set to regenerate and therefore significantly increase performance. Having "Regeneration" in print in an operator's manual would have been as good as an admission of guilt by Federal. Most owners figured out the adjustments anyway and the radios were fairly popular. By setting the "COUP" control to near "0" and advancing the "AMP" control to near the oscillation point, the DX Type-58 (and most other Federals) can be quite sensitive and selective receivers.


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Federal Telephone & Telegraph Co.

Type 61

Introduced in the fall of 1923, the Type 61 was Federal's high-end receiver, selling for an incredible $223. The circuit used six tubes - three RF amplifiers with grid-bias controlled amplification running into the detector stage and two transformer coupled audio amplifiers. One could select either one RF stage or three RF stages, a loop antenna input or external antenna input. One could also select various audio amplification circuits and the second audio interstage transformer has a selectable ratio secondary. In all, sixteen different configurations could be set-up, making the Federal 61 one of the most versatile battery receivers of its day. Though the manual is vague about the regenerative capabilities of the Type 61 ("regeneration" is never mentioned), performance can be excellent if the "COUPLING" is kept near minimum and the "RF AMPLIFICATION CONTROL" set near the oscillation point.


A-K Model 4560 - 1924


 MODEL 4560 - a.k.a. 10-B, "A-K Breadboard"


Arthur Atwater-Kent made a fortune in the automotive ignition and lighting business but moved into radio parts manufacturing around 1922. Initially, A-K offered various kinds of radio parts to build your own receiver. By 1923, complete A-K radios were being offered. Shown is the 1924, Model 4560 (A-K 10-B) in standard finish, (black paint on the cans.) A-K believed his manufactured parts were beautiful (and so do a lot of collectors) so exposing them on open boards seemed the logical design for his receivers. Original selling price for the A-K breadboards was usually around $100. The TRF circuit provided good reception although the upper limit of the tuning was about 1200kc. Quality was top notch, as with all A-K receivers. There are many variations and different models of breadboard sets that were made between 1923 and 1925.



Shown in the photo to the right is one of Atwater-Kent's component parts that were being sold in 1922 and 1923. This is a two-stage, transformer coupled audio amplifier. Connections are via binding posts behind the tube sockets. The potentiometer adjusts the filament voltage on both tubes as a method to control gain or output level. Although the intended tubes were probably UV-201A tubes, this TA was found with two good condition WD-12 tubes installed. Early A-K cans were painted an olive-green color and some of the very early breadboard sets also have cans with this color paint applied. All of the later cans are either black or brown wrinkle finish paint.


General Electric for RCA

AR-812  Second Harmonic Superheterodyne

The AR-812 was the first production superheterodyne offered to the general public. Western Electric was producing commercial superheterodynes earlier and supposedly installed one in the White House. That "fired up" David Sarnoff, who was RCA's GM at the time, to have GE build a superhet for RCA to sell. As with many new types of circuits, the AR-812 prototypes didn't work very well with internally generated noise due to reflexing some of the circuits. Ed Armstrong was called in as a consultant and the problems were reduced to the point where the receiver could be offered for sale. RCA was aiming for Christmas 1923 but delays moved the release date to February 1924. The incredibly high selling price of $235 didn't seem to deter the radio enthusiasts and the AR-812 sold very well. It sold even better when the price was reduced and, by 1925, new-in-the-box, surplus production left-overs, were being sold for $10. The AR-812 did out-perform most of the competition and with a large indoor loop antenna, coast-to-coast reception was possible. Six UV-199 tubes are used and the receiver does have have a small built-in antenna. In fact, some of the advertising for the AR-812 promoted the receiver as being "portable."

The AR-812 uses what RCA called "catacomb" construction. Most of the receiver circuitry and components were contained in a metal box that is filled with hard wax. The external flexible wire connections were called "whiskers" for some reason. It is possible to determine faults in a catacomb by measuring the resistance between various whiskers. RCA provided the data and procedure for testing catacombs. However, RCA wanted the defective catacombs returned or exchanged for good ones when doing repairs. Not possible today, of course, and most restorers repair their own catacombs (if they want the receiver to function.) I use a second-hand toaster oven (usually a few dollars at thrift stores) set to 180F or so to melt out the wax. It will be necessary to carefully remove the lead seals to preserve the embossed "RCA" on them. Also, sometimes a vent hole has to be drilled to allow the heated wax to flow out. Once the wax is removed, repair is straight forward. You'll almost certainly find that some of the very fine wires used in the circuit have broken. This is probably due to expansion and cracking of the wax breaking the fine wires. Once the catacomb is repaired, you don't need to refill it with wax again. RCA used the wax as a method of keeping the superheterodyne construction secret or at least from becoming common knowledge to the technoids of the time.

The AR-812 shown in the photo was found (in 1993) in the upstairs storage rooms above the Crystal Bar in Virginia City, Nevada. The Kolster Loop Antenna (Federal Telegraph Company) and the RCA UZ-1325 horn-speaker were with the AR-812 and the radio had all six 1.5vdc dry cells still installed. The "station cards" are vintage and were penciled in with west coast stations. In the past, the radio had been operated using dry cells for the filaments and an AC operated "B eliminator" for the higher voltages. Just how long the radio, loop and horn had been upstairs is hard to say. Bill Marks, who owned the Crystal Bar then, was an avid collector of all kinds of antiques. The Crystal Bar was famous for its display of various kinds of orchestrons, nickelodeons and other types of mechanical music players. The upstairs was filled with other types of antiques including phonographs, radios and parts. Everything was eventually sold off when Marks died. The Crystal Bar is now the Visitor's Center for Virginia City operated by the VCCTA.



Model XJ

Powel Crosley Jr. got into the radio business because his son wanted a crystal set. The prices were too expensive, in Crosley's opinion, so he bought a twenty-five cent booklet instead and built his first radio. Realizing how easy it would be to build and sell simple receivers, Crosley bought Precision Electric (in 1922) to begin his radio business and the following year formed Crosley Radio Corporation from Precision Electric. Crosley radios are noted for  good performance with inexpensive parts and cabinets. By keeping manufacturing costs low, Crosley was able to offer his radios at very low prices resulting in high sales. His methods of manufacture eventually led to his becoming known as the "Henry Ford of Radio." Crosley went on to owning BC station WLW, owning the Cincinnati Red Legs baseball team, building small cars and many other endeavors. Shown is a 1924 Crosley XJ, a four tube TRF receiver.



Model 51

One of the most common Crosley battery operated regenerative receivers is the Model 51. Crosley sold them for $25 and the little two-tube radio performed quite well. Certainly, the Model 51 shows what can be accomplished when the goal is to build a two-tuber (regenerative detector and one stage of AF amplification) as economically as possible. Crosley was already famous for their ultra-simple "book condenser" that replaced the expensive tuning condenser. The "tickler" was a push-in or pull-out type of control that allowed the operator to control regeneration by changing the proximity of the tickler coil to the secondary coil. A simple push or pull of the regeneration knob changed the position of the tickler coil behind the panel to adjust the regenerative feedback. Most of the other parts used in construction are standard for the period. The cabinet is made out of poplar wood and was given a very basic finish (probably just a coat of shellac.) It didn't matter how cheaply made the Model 51 was - it performed quite well, better than many other more expensive sets. Crosley sold thousands of the Model 51 for that very reason. The Model 51 was available from 1924 through early-1925. The Model 51 shown still has its complete original warranty card attached under the lid. The date on the card is interesting, Dec.25, 1924 - Christmas Day. This 51 is in "as found" condition.


R. E. Thompson Mfg. Co.

The Thompson Grandette - V-50

Roy E. Thompson worked in the Department of Commerce, then for Kilbourne & Clark before buying Wireless Improvement Company around 1917. He started R. E. Thompson Mfg. Co. to obtain a Neutrodyne license from the Independent Radio Manufacturers. The "Independent Radio Manufacturers" was formed by eleven companies who wanted to develop a radio that could compete with the GE-RCA-Westinghouse owned Superheterodynes. They approached Louis Hazeltine for the design work and the Neutrodyne was born. It used capacitive feedback in the RF amplifiers to cancel the tube's interelectrode capacitance which then allowed for higher gain in that stage without oscillation instability. The RF coils were physically oriented at 45 degree angles (tilting) or a 90 degree mounting relationship to reduce any stray coupling between RF stages. The Neutrodyne, when properly designed and manufactured was the best performing TRF radio receiver of the time. While it didn't always perform as well as a Superheterodyne, it certainly performed better than any other type of TRF receiver. Unfortunately for all other manufacturers, unless you were an original "Independent Radio Manufacturer", you couldn't legally build Neutrodynes (see "Grebe MU-1" below.)

The Thompson V-50 was introduced in October 1924. It is a well-built Neutrodyne using five tubes that consisted of two Neutrodyne RF amplifiers, Detector and two stages of audio amplification. Interestingly, the V-50 allows the option of either using the C- bias or not, all controlled by connecting or disconnecting a metal strap across the bias battery connection terminals. At the time, the only reason for using C- bias in the audio section was to prolong the life of the B+ batteries. Also, a "dummy plug" is installed in one of two chassis jacks marked "1" or "2" to select whether one or two audio stages are used for the output jack on the front panel. The Grandette V-50 styling is typical of the 1923-24 Neutrodynes, that is, black panels and three symmetrically mounted tuning dials. Inside the workmanship is first-class. Thompson also sold a matching horn speaker that featured a direct-driven conical diaphragm.

Thompson radios were high priced with the V-50 selling for $125 in 1924. Thompson radios looked like the typical Neutrodyne (e.g., the early FADA.) A few other manufacturers had models out there at half the cost of Thompson's least expensive models. Those cheap radios weren't Neutrodynes but most radio consumers didn't know the difference and were only concerned with the price of their intended purchase. Take a look at the early Freshman Masterpiece (which actually came out before the V-50) as an example of a radio that looked convincingly like the typical Neutrodyne but sold for only $60 (Freshman write-up below.) To the radio-buying public, the Freshman was the better deal - until they got it home and found out how badly it performed. The Thompson V-50 would easily "bury" the Freshman in all areas of performance. Unfortunately, the new Freshman owners found out too late that they had been "taken" by Charlie Freshman.

Thompson's sales were never as high as expected and the company was in constant debt, despite introducing new models. By the end of 1927, Thompson was out of business. Interestingly, Charlie Freshman was also about to be forced out of his company. The days of selling "really cheap" radios were about to end with the introduction of lightsocket-powered radios - AC-operated in most areas, DC-operated in Edison-powered areas (rural areas still had to stick with battery operation.) Even a merger with Freed-Eisemann didn't help Freshman since the 1929 Stock Market Crash was right around the corner.


Chas. Freshman Company

Freshman Masterpiece & 5-F-4

Charlie Freshman entered the radio business at the right time, made a lot of money and then got out of the business to spend that money. Starting in 1922, Freshman began selling radio parts and then moved into fully assembled radios when the Neutrodynes started coming out (late-1923 for the FADA.) Designed to look like the typical Neutrodyne, Freshman's radio, the Masterpiece, sold for half the price at $60. If you wanted it as a kit, the cost was only $17. Freshman's engineers utilized the losses of mounting the RF stage inductance directly onto the metal frame of the tuning condensers to prevent the RF amplifier stages from oscillating. This was Freshman's approach, build as cheaply as possible. It worked, too. At its production height, Freshman was turning out over 1000 radios a day. Only after the novice radio buyer got a chance to listen to a neighbor's real Neutrodyne radio did he then realize how badly the Freshman Masterpiece performed. Reliability was also an issue with Freshman Masterpiece radios with defective interstage transformers and potentiometers being the worst offenders. As Freshman evolved as a business, his radios really didn't. New cabinets and different tuning dials maybe, but the circuits remained basically unchanged.  >>>

>>>  Freshman used a particularly high ratio interstage transformer that was not only unreliable but even when working provided so much gain that the audio distorted heavily. Most of the transformers used 6:1 ratio or even higher while the industry standard was 3:1. By 1928, Charlie Freshman was forced out of the company and Walter Chrysler infused some cash into a merger of Freshman and the Freed-Eisemann Company. While the Freed-Eisemann name was used for the high-priced models, EARL was used for the Freshman models. EARL lasted a year or so, until late-1929 brought on the Stock Market Crash.

Freshman made a lot of radios. While they are very common, it is rare to find one that hasn't had some repairs made to it. After all, the parts were just about the cheapest that Charlie could find. The upper photo shows the typical 1924 Freshman Masterpiece. Supposedly, if the "Freshman Masterpiece" logo isn't present under the switch, then that particular set was the kit version. I've only seen one FM without the logo, so not too many buyers opt'd for the kit.

Shown to the left is the later version of the 5-F-4 model. Earlier versions had external dials while the later version have the dials behind the small windows. This model sold for $49 - really cheap. What is unusual about this particular 5-F-4 is that it is all original and functional. The distortion from the audio is unbelievable due to the 8:1 ratio interstage transformers with no -C bias. Even one of the contemporary radio magazines stated that Freshman's business relied on inexperienced buyers that eventually learned that they had been "taken" by Charlie.




 AMRAD was the American Radio and Research Corporation. Though founded with J. P. Morgan money, Morgan's son ran the company after his father's death in 1913. AMRAD never seemed to be on the "cutting edge" of radio and, despite a lot of money, AMRAD was always a "technologically backwards" company. It was just luck that they became one of the original members of the "Independent Radio Manufacturers" and was licensed to produce Hazeltine-Neutrodyne receivers in 1923. However, in an amazingly incompetent decision, AMRAD didn't offer their Neutrodyne receiver immediately and delayed the introduction until the Christmas season of 1924. The decision to delay their Neutrodyne cost AMRAD thousands of potential sales and the company lost a tremendous amount of money and respect. Within six months AMRAD was bankrupt.

The AMRAD Neutrodyne is somewhat different that the normal layout with one Neutrodyne RF amplifier, Detector and three stages of audio amplification. AMRAD also decided to build the receiver very compactly resulting in one of the smallest of the 1924 Neutrodyne radio receivers.  The Neutrodyne was the last model AMRAD produced before the company went bankrupt (June 1925) and was subsequently purchased by Powel Crosley. By purchasing AMRAD, Crosley was then able to legally produce Neutrodyne radios.



The earliest of the Synchrophase receivers with no chain-drive and no Tone Color control - from late 1924

A.H. Grebe & Company

 "Synchrophase"  MU-1

Arguably, the Grebe Synchrophase is best performing TRF AM Broadcast battery set that was made in the mid-twenties. The circuit was a Neutrodyne and Grebe was sued by Hazeltine (Independent Radio Manufacturers) because of it, though production of the MU-1 was never stopped and continued on, ultimately reaching over 150,000 radios. The MU-1 is very sensitive and will separate signals quite well due to its SLF (Straight-Line-Frequency) condensers and binocular coils. The construction of the binocular coils prevented an EM field from being radiated and eliminated stray coupling between the RF stages. The remaining interelectrode capacitance of the RF amplifier tubes was "balanced out" with feedback condensers (which Grebe called "Balancing Condensers.) Grebe engineers considered the MU-1 Synchrophase's great performance was due more to the design and construction of the unique precision components used in the receiver rather than the Neutrodyne circuit.

The earliest Synchrophase receivers use a single filament control and a volume control that selects various resistors that are across the second audio interstage transformer primary. The small round escutcheons only had "INCREASE" embossed on them. Shortly after "VOLUME" and "FILAMENTS" were added to the "INCREASE" on the small round escutcheons. These early Synchrophases only tune up to 1300kc. Several improvements were added in a mid-1925 production upgrade but the most significant improvements were the ball-chain drive for single-dial tuning and the bandswitch that allowed increasing the upper end of the tuning range to 1900kc.  The bandswitch was actuated by the center dial at either end of its rotation. The chain-drive could be disabled by loosening the knurled nut on top of each outer dial. This would not affect the operation of the bandswitch but allowed for more accurate tuning of the signals. Other mid-1925 additions or upgrades included a "TONE COLOR" control that was actually modified from the old "VOLUME" control. The "TONE COLOR" was now an adjustable resistive-capacitance device installed across the primary of the second audio interstage transformer. The "VOLUME" control was a modification of the old "FILAMENTS" control that changed the component into a dual filament control that separated the detector and AF filaments adjustment from the RF amplifier tubes adjustment, providing better response for receiver output. A mid-1926 upgrade added an improved audio interstage transformer that increased the "low frequency" response to improve the sound quality. Also part of the 1926 upgrade was changing the audio output tube to a UX-112A, requiring an increased B+ of +135vdc and an increase in the -C bias to the audio output tube to -9vdc. Additionally, the "TONE COLOR" control was changed to a selectable capacitance that shunted the 2AF audio grid to -C. Somewhat after the mid-1926 upgrade a cushioned detector socket was added and, shortly after that, all of the sockets were changed to the cushioned-type. There were no other upgrades after the mid-1926 changes and the MU-1 continued in production until around April-May of 1927.

Throughout production there were minor changes to the hardware and assembly, e.g., some sets are found with two lid props and some with just one. Additionally, the dial escutcheons were usually finished in lacquered gold but supposedly some MU-1s had gold-plated escutcheons. Front panels will be found with either linear faux graining or burl (mottled) faux graining. The instruction cards are found in various colors, cream with black letters, yellow with black letters and cream with red letters depending on the vintage of the set. To this day, Grebe's serializing of the Synchrophase remains a mystery. The serialized identification consists of four letters, e.g., "TFZH" or "BWDC", etc. - the letters were not chronologically arranged and defy any sort of decoding. It seems likely that the intent was to obfuscate the actual number of MU-1 receivers being built (at least by serial number inference) since that total built quantity might have figured in a settlement in the pending Neutrodyne suit. Included with the purchase of a new Grebe MU-1 were "Dr. Mu" QSL cards that allowed users to send reception reports to broadcast stations they received on their MU-1 (in the hopes of receiving a return reply QSL card from the BC station.) "Dr. Mu" was an advertising character that Grebe created - a fictitious ancient Chinese philosopher-scientist. "Mu" refers to µ or mu, the gain of a vacuum tube.

There was also an MU-2 available that was a dry-cell tube version initially using six UV-199 tubes. Later versions used four UV-199 tubes and one UX-120 tube. Another option was a Battery Base that the Synchrophase would set on top of. The Battery Base was designed  for the 1924 version of the Synchrophase that used four +22.5vdc B batteries. By mid-1925, two large +45vdc B batteries were now specified and these wouldn't fit into the Battery Base due to their height. Owners could still operate their 1925 set on the four +22.5vdc B batteries since the voltage requirements hadn't changed. When the 1926 version added the UX-112 tube with +135vdc B voltage the set now required three large +45vdc B batteries (beside two C batteries) and there was no way to fit all of the batteries in the Battery Base. However, by 1926, there were smaller +45vdc B batteries available that would fit into the base but their useful life was much shorter than the larger B batteries. Around this time, the Battery Base was rapidly loosing any desirability as an option. Due to the later battery requirements, most original Synchrophase and Battery Base combinations that turn up are the earlier 1924 to mid-1925 versions. Note that the cabinet feet must be removed from the Synchrophase cabinet in order for it to set flush into the Battery Box recessed area.

The court case regarding the Neutrodyne Patent infringement was heard in June, 1927. Grebe lost the case but was able to obtain a Neutrodyne license almost immediately. However by this time the MU-1 was obsolete and Grebe production was moving to single-dial receivers, the Synchrophase AC-6 and later the AC operated AC-7. The Synchrophase MU-1 production had run from mid-1924 up to mid-1927 and an incredible 150,000 receivers had been produced during that time. 

On an additional note: Some Synchrophases will be found with a greenish-gray color to the finish (as seen in the top photo.) This is a reaction that the original finish has with excessive exposure to sunlight (UV.) The original finish was medium walnut color (as seen in the lower photo.)

For the ultimate information source on the Grebe Synchrophase MU-1, including chronological listing of engineering-production upgrades, restoration hints and neutralizing the MU-1, go to "A Guide to the Synchrophase MU-1." Link below in Navigation Index.

photo above: This advertising label was installed inside the cabinet wall on the right side. This label advertises Grebe's Broadcast Station WAHG and also mentions the packet of Grebe QSL cards that were supplied with each receiver.

photo left:  Grebe MU-1 CTPB with optional Battery Box. This MU-1 does not have the chain drive and has the "VOLUME" and "FILAMENTS" controls - no "TONE COLOR" control.


Federal Telephone & Telegraph Co.

Type A-10 "Orthosonic"

Federal was able to become one of the Independent Radio Manufacturers and was able to sell Neutrodynes. The A-10 is Federal's entry-level Neutrodyne selling for $75 in 1925. Like all Federals, the A-10 is well-built with quality parts, most made by Federal themselves. The Neutrodyne circuit helps the A-10 performance but since the condensers are not "straight-line-frequency" types, all of the stations seem crowded at the upper end of the tuning range. Sensitivity and selectivity are good as expected from a Neutrodyne.

This Federal A-10 has had an interesting history that started in Bodie, California - the mining town located 9000 feet above sea level just north of Mono Lake. The last resident of Bodie left in the 1930s. Much of the town had burned down earlier (although many buildings survived the fire) and the abandoned town was left to decay in the high altitude elements. Below Bodie, at the north end of Mono Lake, the Scarvino family had a ranch. By the 1940s, going up to Bodie to "pick thru" the remains was popular with the locals. Supposedly, this A-10 was picked-up by one of the Scarvinos (along with a Cameco horn speaker) and brought back to their ranch. Fast forward to the 1990s, when I picked up this A-10 (and the Cameco horn) from the person that got it from the Scarvinos. It's obvious by the A-10's condition that the radio must had been inside one of the many surviving houses in Bodie (from the mid-1920s up to the 1940s.) In 1964, the state of California made Bodie a State Park and a full-time ranger is now always on duty in town. When visiting Bodie it's hard to imagine that the structures that have survived represent only about 10% of what Bodie was in it's heyday.


GE and Westinghouse for RCA

Radiola 20

Why RCA offered the Radiola 20 is a mystery. RCA was practically the only company that sold superheterodynes and here they were offering a TRF front-end with a Regenerative Detector followed by two stages of audio amplification. Certainly by 1925, the Regenerative receivers had fallen out of favor with AM Broadcast listeners who didn't like the interference caused by their neighbor's regen-set when it was oscillating. However, some realized that the regen-detector was about the most sensitive detector of the day. RCA added two stages of RF amplification in front of the regen-detector which isolated it from the antenna and eliminated that possibility of interfering with your neighbor's radio.

The Radiola 20 tuning condenser is ganged together to provide single-dial tuning but two trimmer condensers allow for fine tuning for best accuracy. Regeneration is labeled as "Amplification." The two pin jacks on the right side of the panel are for an external filament voltage meter. Using four UX-199 tubes and one UX-120 tube, the Radiola 20 is a surprisingly good performer. The UX-120 is run at +135vdc with a -22.5vdc bias and the RF stages are also biased with -4.5vdc. Several different B+ voltages are required for the circuit to perform as designed. When operated correctly and with a good quality cone speaker, the Radiola 20 sounds good and is very sensitive. Note that the escutcheons on this Radiola 20 are the early versions that were given a "gold wash" - sort of a very thin gold plating. Later versions of the Radiola 20 have bronze finish escutcheons that are much darker. 


A-K 20 "Big Box"


Model 20 "Big Box"  &  Model 20-C  "Compact"

Atwater-Kent liked the appearance of his components and his breadboard sets reflect his opinion. However, consumers in the mid-1920s - at least those that weren't technoids - wanted enclosed radios that didn't show any of the tubes and wires that radio enthusiasts enjoyed looking at. Additionally, there were the electrophobics that were always afraid of anything running on electricity and to them the exposed terminals of the breadboards caused no end of concern. A-K finally enclosed the breadboard design in a mahogany cabinet and the set was designated the Model 20. Today's collectors have dubbed this first version the "Big Box" in contrast to the later Model 20-C or Compact. The 20-C reduced the size of the cabinet to the absolute minimum as there is very little space inside the cabinet that isn't radio components. A battery cable is brought out the rear of the 20-C cabinet to allow the set to be connected to batteries. Terminals inside provide connections for the horn speaker and the antenna-ground system. The 20-C was popular and A-K sold a lot of them. High quality components and good performance as was typical of Atwater-Kent.

A-K 20-C "Compact"


American Auto & Radio Mfg. Co.

   American Beauty

Harry Schwartzberg was president of this small company located in Kansas City, Missouri. The American Beauty is typical of the 1925 to 1926 manufacturing style of TRF receivers built by companies that weren't members of the Independent Radio Manufacturers and therefore couldn't legally build neutrodynes. The circuit uses two standard TRF amplifiers, a Detector, two stages of RC coupled Audio Amplification and one stage of transformer coupled Audio Amplification - six tubes in all. The silk-screened panels became popular in the same time period and in many other models these panels became very elaborate works of art. The American Beauty artwork features a rose in each corner to honor its namesake.


F.A.D. Andrea, Inc.

FADA 6    Model 460

Frank A. D'Andrea was the first Neutrodyne licensee of the Independent Radio Manufacturers and his company, who had been making crystal detectors, became the first to offer a Neutrodyne receiver to the public in late-1923. D'Andrea had actually shortened his name to Andrea some time earlier and had several jobs before going into radio. During WWI, he was associated with DeForest and by 1920 had his own company producing crystal detectors. A law suit over crystal detectors caused Andrea to broadened out to complete radios and kits after becoming a member of the eleven Independent Radio Manufacturers. Around late-1925, Andrea was hired engineer Lewis Clement who designed a series "high-end" Neutrodyne receivers. The same basic "high-end" design principles were incorporated into six, seven and eight tube chassis that were then installed into many different types of cabinetry. These "over-built" radios were expensive and performed quite well but were complicated to "hook-up" employing battery cables that had at least ten different connections. In the late-twenties, F.A.D. Andrea, Inc. was purchased by  investors and went bankrupt in the early thirties. Frank Andrea had already started Andrea Radio Corp. by that time and that company continued in business for decades.

The FADA 6, Model 460 is a six-tube Neutrodyne receiver that came out in 1926, selling for around $150. Ruggedly-built with completely shielded tuners that allowed the RF amplifiers to operate without any stray coupling. The 460 has a tuned antenna stage, three Neutrodyne TRF amplifiers, a detector and two stages of audio amplification. The audio output tube is a UX-112A or UX-171A running +135vdc on the plate. The fold-out loop antenna was mounted to the left side of the radio cabinet. There was also optional connections for using an "outdoor" antenna, if desired. If the loop wasn't used then it could be folded down and would store under the lid.

Repairing the FADA 6 Model 460 - Most battery-operated radios are simple circuits with not too many components that are all easy to access. Not true for these 1926 FADA radios. The FADA 6 is the smallest of these over-built radios and is probably the easiest to work on. The difficulty only increases with the FADA 7 and FADA 8. Most battery-operated sets used one B+ bypass capacitor and maybe another on the C- bias. Not FADA,...there are 8 bypass capacitors in the FADA 6. The bypass caps assured the radio circuit performed at a consistent level, even if the batteries were getting weak - at least, up to a point.

The components that are most vulnerable to damage are the audio interstage transformers. This FADA 6 had an open plate winding in the first audio interstage transformer. A collector-friend gave me a set of original FADA transformers that had been removed from a FADA 7 parts set. All of these style FADA radios use the same interstage transformers along with one plate choke. All FADA 6 radios have the audio interstage transformers riveted and bolted together in an assembly designed to fit into a very compact area of the chassis (the FADA 7 and 8 also include the plate choke in the assembly.) This compact area has the large battery cable and terminal board connections directly over it. Also, the wiring harness is routed directly over the transformer assembly. Also, there are several other mountings that have screw ends in the area that interfere with the removal process. In fact, with this FADA 6, the original transformer assembly couldn't be removed unless the battery cable was first desoldered and removed. This was followed by cutting two 6-32 screw ends just at the nut level. Then, by moving the wiring harness slightly out and towards the front of the radio chassis, there was barely enough clearance to remove the transformer assembly. See photo below-left. The transformer assembly then had to have the rivets drilled out so the defective transformer could be dismounted. The same had to be done to the part donor assembly to remove a good original transformer. The transplant requires installing the good transformer into the original assembly brackets and mounting the transformer with 1.5" long, 6-32 screws and nuts to replace the rivets. I used a file to shape the screw heads to look like rivets and then made sure the nut side was facing down when the assembly was installed. See photo below-right.

I had made a drawing of the wires removed so I could reconnect everything easily. Luckily, I also had the schematic from Rider's VOL.1 for reference. I double-checked the wiring as I reconnected the transformer assembly and the battery cable. It had appeared like there had been some repair work done in the past and my double-checking with the schematic paid-off when it turned up a C- connection that was incorrectly wired to the Audio B+. This error probably was responsible for the open transformer. Apparently the radio was never repaired after that.

One unusual design in the FADA radios is that the loudspeaker connection is capacitively-coupled from the last AF amplifier plate. PWR B+ (+135vdc) is routed thru a choke to provide plate voltage to the last AF amplifier tube but the loudspeaker is connected from the plate output capacitor to ground. These large FADA 6 and 7 radios will have two audio interstage transformers and one plate choke in their audio section. The FADA 8 has three audio interstage transformers and one plate choke.

I used three power supplies to operate the FADA 6. Filaments were supplied by a 6vdc 4A Lambda supply. B voltages were supplied by a RCA Duo-Rectron B Eliminator. C bias voltages were supplied by a RCA adjustable dual power supply. Initial testing used a 20 foot long length of wire for an antenna. A Utah cone speaker was used for audio reproduction. I was able to tune in a local station, so everything was working well enough to install the FADA 6 back into its cabinet where it could be operated using the loop antenna.

This testing revealed that the Utah cone speaker was not a very good reproducer. I swapped it for a Peerless cone speaker and the improvement was dramatic. Loud reproduction with good audio (for 1926 equipment.) If even louder reproduction was desired, I could use an outdoor antenna. In fact, with the outdoor antenna, reproduction is so loud the "medium" volume switch had to be used except for DX stations. Using the loop antenna will require the volume switch to be in the "loud" position. Most stations received on the loop will be local BC stations. 

Probably the fold-out loop antenna provides the greatest appeal to these particular FADA models. However, the circuitry is very interesting and the construction is top-notch. Performance is quite good and there's also the convenience of not needing an outdoor antenna or earth ground for decent reception of local BC stations.

photo left: Showing how much wiring is directly over the interstage transformer assembly. The battery cable must be entirely removed and the wiring harness pulled up and pushed towards the front of the radio to have enough clearance to remove the transformer assembly for repair.

photo right: The repaired interstage transformer assembly ready to reinstall



Kemper Radio Laboratories

Model K-5-2


In 1927, Sennett Gilfillan and David Sarnoff met in New York to come to an agreement as to how radio manufacturing in the West would develop. Prior to this time, many small companies were building radios that technically violated many of the patents held by the "Radio Group." The arrangement that Gilfillan and RCA worked out was that in exchange for Gilfillan shutting down its operations in New York and Kansas City, they would be given exclusive licenses for radio manufacture in the eleven Western states. In 1927, this amounted to the manufacture of all TRF radios and a few other key patents. In 1930, the licenses included the Superheterodyne. After 1930, all radio manufacturing in the West had to go through Gilfillan with the other builders becoming sub-contractors protected by Gilfillan's licenses. This arrangement lasted throughout the 1930s and was only changed beginning in 1940.

The Kemper K-5-2 Portable is a five tube TRF receiver with the AF output using a special 3-V Van Horne tube. 10 batteries are required for power and, when not in use, the loop antenna stows in the removable back cover, (there is also a removable front cover that is not shown.) Kemper Radio Laboratories of Los Angeles eventually became Kemper Radio Company.  This K-5-2 dates from about 1927. Performance is very good and sound quality is enhanced by the use of a built-in exponential horn.

Go to our section "Classic Pre-WWII Ham Gear" to see a complete 1933 two-tube receiver and four-tube transmitter, both with separate AC power supplies, all built into a Kemper K-5-2 cabinet - it's impressive. Navigation link at bottom of this page.


Custom-Built Glass Case Neutrodyne Radio

Built by: E. H. Browning, June 20, 1927, Portland, Oregon

Radios that were built into cabinets made of glass served two purposes. First, for the radio parts dealer, it displayed what type of components were available and how they would look in a home-made radio. It's also possible that some dealers actually would build custom radios and the glass cabinet again showed the typical construction and layout of components. There were also instances where a special glass case was used for display of a radio company's model (used by dealers) that would show potential customers the internal construction of the particular model (this use was fairly uncommon.) The second use was a talented "homebrewer" that just wanted to show his building prowess with a radio that was uniquely different. Certainly Glass Case Radios are seldom encountered. They are rare because there were so many problems involved in using glass as a medium for the construction that few were ever built. Today, Glass Case Radio survival depends on the durability of the cabinet to withstand the effects of time, poor storage, careless moving and neglect. Also, the chassis must have been able to survive similar conditions. Most Glass Case Radios date from the mid-to-late twenties. They shouldn't be confused with the glass-mirrored radios of the thirties that were produced by true radio factories (Sparton and some others.) The Glass Cased Radios were built specifically to "show off" the construction and components of the radio circuit, either for dealers or for enthusiastic homebrewers.

The Glass Case Neutrodyne Radio shown above dates from 1927. It was built using primarily components made by the Bremer-Tully Company (B-T.) Six tubes are used in the Neutrodyne circuit, three RF amplifiers, a Detector and two stages of transformer coupled audio amplification. The RF coils use chokes that isolate them from B+ (chokes are made by B-T.) The neutrodyne feedback capacitors are also B-T as are the B-T "TOROSTYLE" (toroid) RF coils.* The dual-section tuning condensers each have an additional trimmer condenser. The tuning dials are National Type B Velvet Verniers. The audio interstage transformers are 4:1 ratio on the 1st AF and 2:1 ratio on the 2nd AF and both are B-T Type T-210 "EUPHONIC" transformers. All of the tube sockets are Type 349 General Radio sockets except for the cushioned detector tube socket which is made by the Benjamin Company. Audio output is accessed via the front phone jacks and the operator can select either one or two stages of AF amplification. Power is supplied by batteries and these are connected via binding posts on the rear of the chassis with the exception of the C bias battery which is connected with flexible wires. The radio is physically rather large at 32" wide and 13" deep. The chassis is made of bakelite. The glass pieces are held in brass channels that are screwed together or soldered to form the glass cabinet. The base is redwood.

Fortunately, this Glass Case Neutrodyne Radio was signed and dated by the builder (which is somewhat unusual.) On the bottom of the wooden base written in pencil is "Bilt (sic) by E.H.Browning, June 20, 1927, Portland, Oregon."

*The toroid style coil form will not radiate an EM field and therefore will not couple to an adjacent RF stage via stray coupling. This leaves only tube interelectrode capacitance coupling that is "balanced out" using the Neutrodyne feedback condensers. The neutrodyne provided high gain and high selectivity without RF stage oscillation.


Crystal Sets

Uncle Al's Radio Shop

"Miracle" Crystal Sets

Uncle Al's Radio Shop built the best performing and certainly the most selective crystal sets available in the 1920s and early 1930s. The crystal sets were sold mainly in the West and most often in California's San Francisco Bay Area. Uncle Al was actually Alex Forbes, who, along with his brother, Henry, built and sold uniquely designed crystal-detector receivers during the 1920s and 1930s out of Oakland, California. Uncle Al's Radio Shop probably started out at either Alex's or Henry's residence in the 1920s. Most of the early crystal sets will have an address on the paper tag under the lid with one of two locations shown, either on Dakota St. or 27th Ave in Oakland. Later locations are at 3905 Hopkins St. in Oakland. Whether Alex Forbes had an actual radio shop (doing repairs and sales) in the early twenties is unknown. By the early 1930s, he was doing business out of a shop location on Hopkins St. that did advertise service and sales.

The Miracle Crystal Set uses multiple coils with fairly loose coupling with variable condensers for sharp tuning. The resulting selectivity is a "Miracle" with Uncle Al's crystal sets having tuning that acted like the popular TRF battery sets of the mid-twenties. Most crystal sets of the time used either "self-resonant" coils that shorted turns for tuning (like Philmore) while others merely had an LC on the antenna with a diode detector, capacitor and phones (some homebrews.) Both of these types of crystal sets will receive multiple stations simultaneously due to their lack of selectivity. Uncle Al's circuit used loose coupling combined with bucking coils for selectivity along with tuned input and tuned detector pick-up coil for better sensitivity. Uncle Al's tuning circuit made the "Crystal Set" a radio receiver that could separate several broadcast stations received within a local area. By 1925, when Uncle Al was introducing his No.1 type, the AM BC band was unofficially 550kc up to 1500kc and within an area like the San Francisco Bay Area several broadcast stations were operating by that time. The Uncle Al's Crystal Set would be able to separately tune each of those stations - something a Philmore or Lemco couldn't do.

The "Miracle" shown in the photo is a No.1 version probably from the mid-1920s. It has two antenna binding posts, the upper is for shorter wavelengths and the lower is for longer wavelengths. The tag under the lid has an address of 27th Ave. which is later than the first sets from Dakota St. but it is still the No.1 type. Uncle Al's cabinets are not finished or they might have been coated with a thin shellac finish that normally is not present on examples found today. Supposedly the wood used for the cabinets is eucalyptus which is very common in that area of California. Uncle Al was always improving the "Miracle" so it wasn't long before the No.1 was replaced with the No.2 with its rotating spider-web detector coil with an adjustment knob between the two tuning knobs. The crystal-detector used on both the No.1 and No.2  was made by Grewohl.

Uncle Al's Radio Shop is still in business in Oakland, California, (though they now sell and service TVs.)

Thanks to Dan Merz for all of the Uncle Al's Radio Shop history.

The photo right shows a late-1930s Uncle Al's Radio Shop promotional card. Note that the card states "MANUFACTURER OF OVER 10,000 SETS - SATISFACTION GUARANTEED!" 


Beaver Laboratories

"Baby Grand"

Certainly one of the smallest radios built in the twenties, the Beaver Laboratories' Baby Grand is shown next to a quarter for size reference. This tiny crystal set dates from about 1922, or so. It is not certain if the Baby Grand was originally considered a "novelty" or a "real" crystal receiver.


Betta-tone Radio Co.


These small crystal sets, built into a file-boxes, were popular in the mid-twenties. Construction was usually good and performance was satisfactory considering the low price they sold for. The Betta-tone is from about 1924. Like most of its contemporaries, the Betta-tone features a tapped coil with switched contact controls for tuning in stations and a "cat's whisker" to find a sensitive spot on the galena crystal for detecting the incoming signal. Earphones connect to the right binding posts while the aerial and ground connect the left binding posts.

There was also another crystal set that is almost identical to the Betta-tone, built by Lemco in San Francisco.


Philmore Mfg. Co.


Philmore Mfg. Co. probably made more crystal sets, over a longer period of time, than any other manufacturer. Most of Philmore's line was fairly low quality with very low selling prices. The "Blackbird" uses a coil wound on a wooden form with a slider actuated by the tuning knob. The crystal detector has a glass cover over the "cat's whisker." The black wrinkle finish metal case gives the appearance of a substantial amount of circuitry but the few components used are all mounted on the back of the unfinished metal panel. Some examples of the "Blackbird" have a "crazed" painted front panel that usually appears to be gold in color. Later "Blackbirds" changed the metal case to heavy cardboard. Shown is an early Philmore from the late-twenties or early-thirties. By the 1940s, Philmore crystal sets had molded plastic cases.


Homemade Crystal Sets

Almost everyone has at one time or another built or used a "homemade" crystal set. They are easy to build, inexpensive and sometimes performance can be quite good. Through the twenties, homemade crystal sets abounded with popularity and several examples can still be found (they're still popular to build today.) Common materials used for the homemade set's coil form were Quaker Oats, Alber's Wheat or almost any round cardboard container that was available. Some high-class builders would opt for a pre-constructed oak box, though most builders were content with just a wooden board to mount the parts on. The crystal set shown was built by M.H. Dodd probably in the early 1920s. Dodd's circuit is unusual in that a tuning condenser is used BUT it's tuning the primary of the coil. The secondary is untuned. Performance is, as expected, quite poor. I'm sure Dodd was thinking of much earlier wireless hook-ups where tuning the antenna primary was considered important, as in many pre-WWI types of tuners. It became more common to tune the secondary with an air variable capacitor after WWI..

We have several Dodd pieces including his Homebrew Three-tube Set, his AK-40, this Crystal Set and his complete 1912 Wireless Station - for details on the Wireless Station go to "M.H. Dodd's 1912 Wireless Station" in the navigation Index below.


Early AC Radios (1927-1929)


Model 37 - "Modernistic Style"

The Model 37 was Atwater-Kent's first, self-contained, AC operated radio (the Model 36 had a separate, AC power pack.)  Rugged construction and the TRF circuitry resulted in a reliable, good performing radio. Although nearly all of the Model 37 production was finished in a brown wrinkle finish called "Crystaline Enamel", sometime in the production year of 1928, a small number of Model 37 radios were finished in an "art deco" style. These Model 37s were dubbed "Modernistic Style" and featured a matching Type-E speaker. The silver and black decor was achieved by using stencils and a light spray painting technique - something like "air brushing."  The finish was very thin and thus was subject to much wear. It's very common to find "Modernistic Style" cabinets with a lot of chips and scratches. Originally, the paint on the "Modernistic Style" was not a glossy finish but was more of a "matte finish" or "semi-gloss." There are two variations of the Type-E speaker. When the "Modernistic Style" matching speaker was fitted with the "thin wood" type of cone, the cone was painted flat black. When the "Modernistic Style" matching speaker was fitted with the thick embossed paper cone, the cone was painted silver. The Type-E speaker shown above has the paper cone and is all original with its proper silver paint. Estimated production is around 10,000 radios, which for Atwater-Kent was a "small run." Today, the "Modernistic Style" is rarely seen. Fortunately, most examples that turn up seem to have the matching Type-E speaker still with the radio - probably because it's pretty obvious that the two pieces went together. This particular "Modernistic Style" was originally purchased in San Francisco and for years made its home in San Francisco's "Chinatown."

Recently (2012,) the television show "American Restorers" featured a "Modernistic Style" radio as one of their restoration projects. Besides several factual errors being presented as expert knowledge, the restoration itself was inaccurate and incomplete. I suppose stating a few times that the radio was a 1926 model was just an oversight by the writers but even the most novice of radio collectors would know that the major introduction of AC-operated radios was announced in late-1927 and that most production examples are actually from 1928. The melting out of the black wax in the power supply box was accomplished with a propane torch - very funny. Most restorers would have used a small oven (like a "used" toaster oven) to slowly melt-out the wax (or maybe even used the old freezer trick.) Plastic wire used in the restoration was inexcusable since there are many sources for the correct original type wire. While the new paint job was stunning, it was finished off with several "clear coats" to make the end-result super glossy - beautiful, but not very accurate. The panning close-up shots of the cabinet revealed a missing Dial Index piece. These are easy to find (or replicate) - why was it left off? The vacant holes above the tuning dial should have been a clue that something was mounted there. Perhaps the most incredible part was the cost of the restoration - $1100 - Wow! Like most of what you see on television, "American Restorers" is an entertainment program and what is presented there should not be taken as expert advise or even correct information - especially when it comes to radios and radio restoration.



Model 40

The Model 40 was one of the most popular of the metal boxed, AC-operated radios produced A-K. Probably, the reason that so many have survived is that the radio was built like a little "tank." There might be problems that develop in the power supply which is filled with hard wax. This makes repair of the power supply somewhat difficult. However, many Model 40 still operate fine on all-original parts. A-K made all of their own components and most of them were high-quality parts. The 1928 A-K Model 40's circuit is TRF and uses seven tubes.

The Model 36 was the first AC-operated radio from A-K in 1927 and the Model 37 was the first AC-operated metal box radio with built-in power supply (and the Model 35, a six-tube battery set from 1926, was the first A-K metal box radio.) Arthur Atwater-Kent felt that the mahogany wooden cabinets he had been making cost too much to manufacture. He knew that a stamped steel cabinet would be cheap to make. It could be painted which was also cheap and easy to do. He just had to convince would-be radio purchasers that these painted steel boxes were stylish and would fit in with the late-twenties decor. With a lot of advertising, A-K was able to change the tastes of radio buyers and the metal box radios became quite popular for a short time, about 1928 up to 1930. A-K even sold a console radio in a metal cabinet. Today's tastes are very different and many collectors find all of the metal box radios ugly, regardless of who the manufacturer was.

The A-K Model 40 shown belonged to M. H. Dodd and was acquired along with Dodd's 1912 Wireless Station in 1999. This Model 40 has the earlier style tuning dial. Later versions have larger numbers and a different style grip. While the Model 37 top tag depicted the Mayflower (or, at least a sailing ship,) the Model 40's tag just has "ATWATER-KENT" embossed on it.



  Screen-Grid Model 55

One of the last of the stamped metal box TRF radios from Atwater-Kent, the Screen-Grid Model 55 uses type 24-A tubes. These are tetrodes which have more gain than the type 26 triode tubes used in earlier models. The Model 55 also uses an electro-dynamic speaker, housed in a round metal cabinet that is mounted to a small pedestal. The design of these speakers are very close to the speakers used in all later radios consisting of a field coil magnet and a low-Z voice coil with paper cone. Some of the construction is slightly different in that a separate suspension is used around the rim but basically the A-K speaker is modern in design. Sound quality (for a 1929 table radio) is very good.

The Model 55 was a departure for A-K in the paint finish. Unlike the earlier metal boxes, the Model 55 is painted with high-gloss lacquer. This particular one is in black and green, however sometimes black and red was used. Since the finish was smooth and glossy, it's very unusual to find any Model 55 that's in good condition, cosmetically anyway. Most examples are severely chipped because the smooth lacquer didn't have the durability of the heavier wrinkle finishes. The Model 55 shown is the best condition one I've encountered. There are a few chips where the speaker sat on top of the set but otherwise it's in excellent condition. Nice cosmetics really doesn't help since most collectors still find these metal box radios hideous looking.



Radiola 60

RCA's "tour de force" superheterodyne, the Radiola 60, was certainly the best performing superhet available in 1928. AC operation, 9 tubes, powerful sounding audio from a single-ended 71-A, cathode type 27 tubes used in the rest of the radio with the exception of the type 80 used for the rectifier. The Radiola 60 was well-built and today many still function quite well on all original parts. The weakest point of the radio is the multi-tap wire-wound resistor used to reduce voltages for various functions. Since this puts the B+ in a series string, if any section of the resistor opens, then the radio will not function. It's easy to repair by installing a correct value WW resistor across the open section. With an outdoor antenna, the Radiola 60 will pick-up just about any signal on the AM BC band. Unfortunately, RCA didn't include a calibrated dial, the Radiola 60 uses a 0-100 scale on the tuning. Two types of escutcheons are found on Radiola 60s - dark bronze, as shown in photo and also, black with silver lettering.

There were a few different speakers available for the Radiola 60. The Radiola 100A was a metal "mantle clock shaped" that sounded quite nice. The speaker shown in the photo left is the Radiola 103 "Tapestry" Speaker. The frame of the speaker is made out of "repwood" or sirocco, a pressed wood that could be molded into any shape. This was then stained. The speaker mounts to the back of the frame and then a cardboard cone was mounted behind the speaker. The cardboard cone was covered with very fine brown cloth. For not having a true cabinet, the Radiola 103 sounds surprisingly good.

The first vintage radio that I bought for myself was a Radiola 60. I was fourteen and paid seven dollars for it (in 1964.) It was a consolette Radiola 60 sold by Sherman-Clay in 1932. Sherman-Clay had bought "left over" production Radiola 60s (very cheap in 1932.) They then had a local California cabinet shop build the console base and install a Jensen Concert Dynamic Speaker. These radios were then sold as "new" models in 1932. The Jensen speaker does make the Radiola 60 sound like a 1930s console.


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Website Navigation Index

-  WHRM History  ~  Nevada Radio History  ~  The KOWL XMTR  ~  Full Length Articles with Photos -


Western Historic Radio Museum Information
 Contact Info, Museum History 1994-2012, Museum Photo Tour, Using Photos and Info from this Website & Radio Value Info

Nevada Radio History - 1906 to 1930
Arthur Raycraft, Nevada's "Father of Wireless," America's First Radio Tour, Early Nevada BC Stations & More

KOWL's Gates BC-250L BC Transmitter
2007 Move from Lake Tahoe - Restoration - PLUS -  2013 Move to Dayton, Nevada & Getting on 160M

Parish House History
1876 to Present
Virginia City, Nevada

Lots of Photos


- Wireless Apparatus, 1920s Radio and Communications Equipment  ~  Full Length Articles with Photos -

M.H. Dodd's 1912 Wireless Station
100th Anniversary  Edition 
Includes New Photos, Reassembly Info and Lots of Original Vintage 1912 B&W Photos + Reassembly in Dayton

Universal, Intermediate Wave and Short Wave Models History, Restoration and Operation - Lots of Photos

"A Guide to the Synchrophase MU-1"
Comprehensive Manufacturing History, Restoration, Neutralizing, Performance Information - Lots of Photos


 SE-1420, IP-501 & IP-501A
"The Classic Shipboard Wireless Receivers"
Comprehensive History, Restoration and Operation Info - Tuning in NDBs with IP-501-A

Vintage Long Wave Receivers
Long Wave Receiver Profiles, Loop Antenna Info, NDB Info and Log,
Fallon NV "Master - M" Loran Station Tour



- Vintage Communications & Amateur Radio Equipment  ~  Full Length Articles with Photos -

National Co. - HRO Receiver
"The Cream of the Crop" 
Comprehensive History, Serial Numbers, Restoration, Lots of Photos & More

National Co. - NC-100 Series
"Moving Coil"  Receivers 
Comprehensive History, Serial Numbers, Restoration & More - Includes Civilian Versions, Military Versions & Airport Versions

Hallicrafters SX-28
"A Pre-war Masterpiece"

Comprehensive History, Serial Number Analysis, Restoration Details & More

Patterson Radio Company
   PR-10 Receiver & Pre-selector              

Comprehensive History, Los Angeles Radio Mfgs History, Circuit Details, Serial Numbers, Restoration Details & More

 RCA's Amazing AR-88 Receivers
Comprehensive History, Restoration Info, How to do IF Sweep Alignments, Serial Numbers & More

RCA's Legendary AR-60 Receiver
Comprehensive History, Serial Number Analysis, Restoration Details & More - including the AR-60 connection to Amelia Earhart's Disappearance

Hammarlund Mfg.Co.,Inc
The Incredible Pre-War 'Super-Pro'
omprehensive History, Serial Number Analysis, Restoration Details. Includes info on the Hammarlund Comet Pro

Hallicrafters DD-1 "Skyrider Diversity"
Comprehensive History, Serial Numbers & Restoration Details

Hallicrafters' "Super-Pro" R-274 Receiver
Comparison of the SP-600 to the R-274(SX-73) in detail, best features of each. VOTE for your favorite Super Pro


-  Rebuilding Communications Equipment  ~  Full Length Articles with Photos -

Rebuilding the R-390A Receiver
Detailed Restoration Information for each module with Lots of Photos

Rebuilding the ART-13 Transmitter
Detailed Restoration info - includes details on building AC power supplies (with schematics) Lots of Photos

Rebuilding the Hammarlund SP-600
Detailed Restoration Information with Lots of Photos

NEW!        T-368 Military Transmitter                  
Detailed Information on Reworking, Testing and
Operation with Lots of Photos

Rebuilding and Operating the AN/GRC-19
T-195 XMTR & R-392 RCVR

 Detailed Information with Lots of Photos

Successfully Operating the BC-375 on the Ham Bands Today
Detailed Information on Power Set-ups that Work, Dynamic Neutralization, BC-191 Info & More

Rebuilding the Collins 51J Series Receivers
Detailed Restoration Information with Lots of Photos - Includes R-388 Receiver

Rebuilding the BC-348 Receiver
Detailed Information on all BC-348 Types, Dynamotor Retrofit Information, AC Power Supply Enhancement - Lots of Photos

Building an Authentic 1937 Ham Station
Utah Radio Products - UAT-1 Transmitter


- WHRM Radio Photo Galleries with Text -

Entertainment Radios from 1922 to 1950

Roaring 20s Radios
1922 to 1929

Vintage Table Radios
1930 to 1950

Floor Model Radios (Consoles)
1929 to 1939

Only Zenith Radios
1930 to 1940

Communications Equipment from 1909 to 1959 - Commercial, Military & Amateur

 Early Ham & Commercial Wireless Gear
1909 to 1927

Classic Pre-WWII Ham Gear
1928 to 1941

WWII Communications Equipment
1941 to 1945

US Navy, US Army Signal Corps, Allied Gear

Commercial & Military
Communications Gear
1932-1941 & 1946-1967

Post-WWII Ham Gear
1946 to 1959

Vintage Broadcast Equipment, RTTY, Telegraph Keys & Vintage Test Equipment

Vintage Microphones
 & Vintage Broadcast Gear
1930 to 1950s

Radio Teletype - RTTY - with Real Machines
includes TTY Machines, Military TUs and Amateur TUs

Telegraph Keys - 1900 to 1955
"From Straight Keys to Bugs"
Hand Keys and Semi-Automatic Telegraph Keys

Vintage Test Equipment
1900 to 1970

Includes Tube Testers, Freq Meters, Wobulators and More


Radio Boulevard
Western Historic Radio Museum

 Vintage Radio Communication Equipment Rebuilding & Restoration Articles,

 Vintage Radio History and WHRM Radio Photo Galleries

1909 - 1959



This website created and maintained by: Henry Rogers - Radio Boulevard, Western Historic Radio Museum 1997/2017






Key Words Antique Radio Vacuum Tubes Amateur Radio Ham Radio Museum Vibroplex Telegraph Keys Wireless Virginia City Horn Speakers Catalin Radio Repair Radio Restoration Radio Personalities Key Names Zenith Philco Scott McMurdo Silver Victor Nipper Atwater-Kent RCA Collins Hallicrafters National