1922 Deforest RAdiohome DT-700 - Deforest Radio Telephone & Telegraph Company

Deforest DT-700


  Deforest Radio Telephone & Telegraph Company first sold this receiver in 1922.  A single tube receiver  that required  a headset for listening or could be connected to one of the early amplifiers of its day. The operator would change coils for different frequencies.  It originally sold for $36.00.



The  instructions for battery hook up, ground and antenna are in the lid.

Antenna Set-up


The recommended antenna and ground set-up in 1922.

Atwater Kent 3955 (model 3) early version 1922 Atwater kent Manufacturing Company, Philadelphia (procured from the Howard stone collection)


Open Set (Breadboard)

 Although officially called an "Open Set", for obvious reasons it is more commonly referred to as a "Breadboard" radio. The 3955 is a TRF radio without regeneration.  The inventor of the regenerative circuit, Edwin Armstrong held a patent on his invention beginning in 1914 and A. Atwater Kent, the founder of Atwater Kent Manufacturing, did not want to  buy a license and pay a royalty on the radios he sold. (Click  photo on left for schematic.) 


Armstrong Patent Work Around

 Atwater Kent sold the model 3 with a tuner, detector and two stage amplifier, leaving a space between the detector and tuner for the buyer to add a variometer for regeneration.


Tube Line Up

The Atwater Kent 3955 was designed to use one UV-200 tube and       two 01A tubes or three 01A tubes. .

1923 RCA Model II AR800 Portable - RCA Victor Company, inc. new york city


Radiola II

Production started in December of 1922 at General Electric for RCA. The Radiola II is a TRF radio with regeneration.  GE stopped producing the radio in 1924.


Tube Lineup

As you can see below,  the Radiola II used two UV-199 tubes.



Early models use two "B" batteries mounted in the back for 45 volts of power. Later models could drive a loudspeaker by using 90 volts and a "C" battery to reduce distortion.



Compact Design

The Model 5 was the only open set officially sold under a single digit model number, the other open sets were given model numbers by collectors.  The radio consisted of a  Type 11 tuner and a five tube amplifier unit that used one tube for detection, two for  RF amplification and two tubes for audio amplification. The tube line up was five UV- 01A tubes or one UV-200 as a detector and four UV-01A tubes. (Click photo on left for schematic.)


A Short Production Life

With sales beginning on September 7th, 1923 the model 5 was Atwater Kent's attempt to reduce the complexity and cost of radios.  However, the model 5 had poor selectivity with only one tuning device and the number of radio stations was growing rapidly in 1923.  Radios designed for tuning in  one or two stations, which is all many people could receive before 1923,  were doomed to obsolescence.


Ugly Duckling to Beautiful Swan

Despite being a poor receiver and  corresponding poor sales, the  model 5 is one of the rarest and most sought after radios among collectors today.

1922 RC- RCA Victor Company, New York city

RCA/Westinghouse Radiola Model RC


In 1922 RCA came out with the RC model, which was the 1921 RA tuner and DA detector/amplifier consolidated into one unit.  A  TRF receiver with regeneration,  it originally sold for $133.



The RC could  tune from 170 to 800 meters of the broadcast band and more with the optional "Long Wave Load Coil". 

Tube Line Up


 The RC could use a UV-200 and two UV-201 tubes or three UV-201 tubes. 

Atwater Kent 4052 (Model 6) 1923 ATWATER KENT MANUFACTURING COMPANY, PHILADELPHIA (procured from the ron frisbee collection)


The 4052 open set was another radio with poor selectivity. Very capable of tuning in the two frequencies that most stations used in 1922 and early 1923, it soon became outdated as more stations and frequencies were added. (Click photo on left for schematic.) 


Tube Line Up

The model 6 was designed to use four UV-01A tubes or one UV-200 as a detector and three 01A tubes in the T/A unit.


The Parts

At the left end of the radio is a Type 11 Tuner, next is the Detector. The smaller unit in the back is a RF transformer and in front of that is a Potentiometer.

Paragon Model RA-10 tuner 1920 Adams-MOrgan Company, Montclair, New Jersey

No tubes


The RA-10 was capable of tuning both broadcast and long wave frequencies.

Needs Help


The RA-10 needed a detector tube unit to produce an audio signal.

Paragon Model DA-2


The DA-2 , also sold in 1922, was designed to be paired up with the RA-10  providing a detector and two stages of amplification.

Atwater kent 4066 (model 7) 1923 ATWATER KENT MANUFACTURING COMPANY, PHILADELPHIA (Procured From the Ron Frisbee collection)

Atwater Kent's First 5 Tube Set


The 4066 was designed to use five UV-201 tubes or a UV-200 detector and four UV-201 tubes. (Click photo above for schematic.)

A Second RF Stage Is Added


The second RF stage boosted the signal so weaker stations could be listened to with a speaker horn.

Poor Selectivity


The model 7 , with a single circuit tuner, suffered from poor selectivity.

Crosley model 51 - 1924 Crosley radio corporation, cinncinati, ohio

TRF With Regeneration


The Crosley 51 was the next step up from the Crosley 50, adding an amplification stage so a speaker horn  could be used for listening.

Tube Line Up


Two UV- 01A tubes comprised the original line up, later models could use UX based tubes and an added connection for "C" allowed the user to use a more powerful amplifier tube,  such as a 71A or 112A .

Great Performer


The Museum's Crosley 51 is a great performer for a simple design, bringing in many stations clearly  with plenty of volume.

Radiola RS - 1923 RCA Victor Company, 223 BROADWAY, New York City

An Aeriola Senior Plus Amplification Circuit


The RS is a TRF radio with a single AM circuit and regeneration.

Tube Line UP


Designed for using two brass based, tipped WD-11 tubes. Those tubes were larger than the later model WD-11 tubes in the photo which made them easier to remove.

RCA Label


The RS was manufactured by Westinghouse for RCA.

Atwater kent model 4445A (9A) 1923 ATWATER KENT MANUFACTURING COMPANY, PHILADELPHIA (procured from the ron frisbee collection)


Later Version Of Model 9

This version of the  4445, the 4445A, came out a year after the original.  (Click photo at left for schematic.)


Variometer Tuned

The 9A is a TRF radio without regeneration.


The Tube Line Up

The 9A was designed to use four UV base 01A tubes or a UV base 00 detector tube and three 01A tubes.

A. C. Dayton xl-5 1924 - A.C. dayton company, Dayton ohio


Three Dialer

The XL-5 is a TRF radio without regeneration, three AM circuits and sold for $115.00 


Five Tube Line Up

The XL-5 was designed to use five 01A triode vacuum tubes.



The XL-5 required 5 volts filament power, 22 volts detector power and 90 volts  for  amplification.

Atwater kent 4640 receiver, (model 20 big box) 1924 ATWATER KENT MANUFACTURING COMPANY, PHILADELPHIA


Three Dialer

The model 20 "Big Box" is a TRF radio without regeneration.  It contains three AM circuits and is broadcast range only. A later model, the 20C, is the same circuitry in a smaller cabinet.


Tube Line Up

The model 20 uses a five tube line up consisting of five 01A tubes or a 00A tube as a detector and four 01A tubes.


An Excellent Receiver

In the hands of a skilled operator, the model 20 is an excellent receiver with good sensitivity and selectivity  along with a relatively strong amplifier for it's era.

crosley Trirdyn 3R3 Special 1924 Crosley RAdio Company - Cincinnati, OhIO



The 3R3 Special is a TRF radio with regeneration.


Loading Coil

The 3R3 Special was built with an antenna loading coil, seen below  attached to the left side interior of the radio cabinet.


Tube Line Up

 The 3R3 was designed for to use three UV- 01A tubes.

4660 (model 9c) 1924

Another Radio Using The Model 9 Name


The model 9C seems to be identical to the 10C except for having one less RF amplifier.  A TRF receiver without regeneration , as was all of Atwater Kent's "Open Set) radios.

Variable Condenser Tuned


The 9C uses two variable condensers instead of a Type 11 tuner and a Coupled Circuit Tuner used in the earlier versions.

Tube Line Up


The 9C could use four 01A tubes or a type 00 tube as a  detector and three 01A tubes.

grebe Model cr-8 1921 Grebe, A.H. & Company - Richmond hIll, New York

Broadcast & Longwave Receiver


TRF radio with regeneration, two AM circuits.

Tube Line Up


The CR-8 is a one tube receiver designed to use a UV-200 vacuum tube.  



The CR-8 has a range of between 150 - 1000 meters.

4700 (10C) 1924-ATWATER KENT Manufacturing co., Philadelphia

Introduced May29, 1924


The Atwater Kent model 4700 (10C) was the fourth and last version in the Model 10 series of radios. The designation "10C" was used to identify the radio in documents from the factory so, like the Model 5 it could be considered correct to refer to this model as a 10C . (The first version, the Radiodyne, can be found in the notables section. It has its own interesting story.)

Over 41,000 manufactured


Design changes made to the 10C included elimination of the potentiometer that controlled RF amplifier grid bias and replace it with 800 ohm damper resistors. Another change was eliminating the by-pass condensers on the RF amplifier filaments. 

Two Versions


Two versions of the 10C were produced, a shorter more compact version also designated the 10C was manufactured on a twenty-six inch board, three inches shorter than the standard model 10C.

Colin/Kennedy type 281 receiver 1921 colin B. Kennedy Company, San Francisco CAlifornia & St. Louis Missouri

High End Receiver


The type 281 was a top of the line receiver in it's day with an $80.00 price tag.  A TRF design with regeneration, it had a range of 175 to 600 meters.

Tube Line UP


The type 281 was designed to use a UV-200 tube.



The 281 could be used with headphones  or paired with the matching 521 two stage amplifier above to drive a speaker horn.

4910 (model 12) 1924 Atwater Kent Manufacturing

The Cadillac of Atwater Kent Open Sets


It wasn't too hard for Atwater Kent to bring out the model 12, it's basically a model 10 with an extra audio amplifier stage. Back in the 20s you bought this one for bragging rights.

New Tube Islands


The 4910 model 12 exchanged the detector/two stage amplifier for a detector/single stage unit followed by a two stage amplifier unit.

The 4620 (12B)


The follow up to the 4910 model 12, the model 12B had an additional potentiometer on the left hand side next to the first variable condenser.