|Year: 1955||Type: Radio - or past WW2 tuner|
|Semiconductors (the count is only for transistors)||5: 2T51 2T52 2T52 2T53 2T12|
|Tuned circuits||5 AM circuit(s)|
|Wave bands||Broadcast only (MW).|
|Power type and voltage||Dry Batteries / 4 x 1,5 Volt|
|Loudspeaker||Permanent Magnet Dynamic (PDyn) Loudspeaker (moving coil) / Ø 2.5 inch = 6.4 cm|
|Power out||0.05 W (unknown quality)|
|from Radiomuseum.org||Model: TR-55 - Sony; Tokyo|
|Material||Modern plastics (no Bakelite or Catalin)|
|Shape||Very small Portable or Pocket-Set (Handheld) < 8 inch.|
|Dimensions (WHD)||5.5 x 3.5 x 1.5 inch / 140 x 89 x 38 mm|
In April 1955 SONY has built a prototype of it's first Transistor Radio, the TR-52, looking like United Nations Building - but TR52 was never really released because of the front-plate "ungluing". This model, TR-55 (TR 55, TR55) has then been produced as the first SONY Transistor Radio for sales in August 1955. TR-55 is a superheterodyne and can also be used with earphone. TR-55 was the first transistor radio produced and sold in Japan. It uses the following transistors: 2T51 (oscillator-mixer), 2 x 2T52 (for IF), 2T53 (AF driver) and 2T12.
|Net weight (2.2 lb = 1 kg)||0.6 kg / 1 lb 5.1 oz (1.322 lb)|
|Price in first year of sale||18,900.00 yen|
Model page created by Ernst Erb. See "Data change" for further contributors.
All listed radios etc. from Sony; Tokyo
Here you find 2204 models, 1857 with images and 392 with schematics.
Hits: 1485 Replies: 1Comments on the Circuits of the first Transistor Radios
Comments on the Circuits of the first Transistor Radios
Translated from: Gebert W Anmerkungen zu den Schaltungen der ersten Transistorradios Funkgeschichte 115 (1997) 241-44 by W Gebert and M Burgess
Wolfgang Gebert, Berlin
In the USA on the 18th October 1954, the "Regency TR-1," developed by Texas Instruments was launched on the market. It was the first mass-produced transistor receiver in the world and arrived earlier than the professional world expected. It was a true international sensation (2).The circuitry of the Regency shows some peculiarities. The circuit of the self-oscillating mixer stage, the base bias voltage of the second IF stage from the AF power stage, the unusual IF of 262KHz and the supply voltage of 22.5 V are all characteristic of the device. Other experimental circuits of the time, as well as the upcoming transistor receivers from 1955 below, deviate from its circuit design significantly.A great similarity is apparent when comparing the circuit of the "Telefunken TR-1" with the "Regency TR-1" (Fig. 1). After the initial pioneering work in the semiconductor factory at Ulm, it is clear that the Hanover factory became active only after the release of Regency receiver. It could be thought of as follows (but unfortunately there are no relevant authorities):They adapted the Regency’s circuit to their available transistors. Because these were pnp types, the supply voltage needed to be reversed. Also since they had poorer RF characteristics, the IF stages were increased to three and the self-oscillating mixer was replaced by separate mixer and oscillator stages. This was necessary to reduce the mixer transistor noise factor. The intermediate frequency was virtually the same. Of course, the RC components to neutralize the IF stages had to be changed. Moreover, they used the same components values, where possible. (There were, however, scarcely any alternatives.) The speaker was similar to the Jensen model used in the Regency.The claim that the development and manufacture of the Telefunken TR-1 took place in the summer of 1954 (3), is probably questionable. Whether a pocket portable was seen behind closed doors at the Hannover Fair in March 1955, is yet to be determined (4).A Regency TR-1 (with Intermetall transistors) would be shown at the Düsseldorf Radio Exhibition in 1955 by Intermetall (6).
Figure 1: Circuit of the "Telefunken TR-1" dated August 55 (top) compared to the "Regency TR-1" from November 54 (bottom). The similarities are obvious. (click on image for full scale schematic)
RCA Development Circuit and the Sony TR-55
I would be very grateful for more information on the theme of "TR-1." I am at w.gebert[A*T]gebert-berlin.de
Figure 2 Schematic of the third RCA radio early 54 (bottom) compared to the Sony TR-55, August 55 (top) (click on image for full scale schematic)
Have to ask again stupid:
This is a "full" - transistor receiver?
 Bogner, G: Telefunken-Taschenradios 1955-1960. Funkgeschichte No. 113 (1997), p 112-125
 Wolff, M F: The secret six-month project. IEEE Spectrum, December 1985
 o.A.: Transistor Vollsuper. Funk-Technik H. 5, 1956, p 124
 o.A.:Radio Mentor H. 6, 1955, p 299: Editorial "Something really new for the Europe was in the air in Hanover but not even demonstrated: Transistor pocket sets and transistor automotive radios.”(ie Radio Mentor suggests that these could be seen unofficially!)
 Dr. Rost: Kristalloden-Technik. 2. Aufl., p 417ff.: VolI-Transistor- Mittelwellen-Super. Verlag von Wilhelm Ernst & Sohn, Berlin o.A.: Bericht über die Funkausstellung Düsseldorf. Radio Mentor H. 10, 1955, p 645ff.
published in Funkgeschichte No.115 (1997) S.241-244
Funkschau 5 /1956 p.174-175 Schlegel, H.: Der Transistor-Taschen-Super Telefunken TR1
Proceedings of the IRE 8 /1955, p.662ff Holmes, Stanley, Freedman: A Developmental Pocket-Size Broadcast Receiver Employing Transistors
Electronics 7 /1956 p.120-124 n.n.: Transistor Circuitry in Japan
Further reading on the circuitry of the first transistor radios:
Pye did the earliest UK set under the PAM brand (PAM710). As the transistors had poor frequency response the IF was lowered. The IF was only 315 KHz. 1956
An early Bush (ETR82) based on MB60 case (tube set) / TR82 (all transistor) used a transistor inverter to power DK96 valve so as to manage Shortwave, the rest was transistor. 1959.
Ever Ready Sky Leader was their first all transistor model in 1958.
Many car radios switched from Vibrator or Transistor inverters for HT to running ECH83 and rest of valves of 12.6V and Germanium transistors (push pull PNP with transformer, or complementary PNP/NPN transformerless push pull).
Also some early UK Transistors sets used point to point wiring & tags, like old valve sets. Pye (who made the PAM710) made the 1st Jewel Box Battery Valve set (with mains) using the "traditional" chassis (early 1955), but the 2nd Jewel Case, (Battery only valve model) P114BQ was one of the earliest UK portable Radio sets with a PCB (slightly later in 1955). After the PAM710 they made the transistor P123BQ 1957 (which is like the valise valve sets without a lid) with their own Pye brand, though there are claims that a Pye branded PAM710 exists. Later was the Pye Q3 (also sold as Invicta 30) which was likely early 1959 (listed 1960? here, but Q4 is likely the 1960 Model). The Q3 is inexplicably "Jewel box" styled, i.e. a box with a lid like so many Vidor valve sets and some other 1950s Pye Valve portables.
Pye don't seem to have capitalised on their early transistor developments. While Hacker and Roberts proved there was a market for "quality sound" transportable Transistor sets, the rest of the UK makers in UK factories seem to have made neither the Asian small cheap pocket sized sets nor the "Quality models" in the early 1960s. Five markets for transistors emerged in the 1960 and early 1970s: the cheap and small as possible pocket portable, the Alarm clock Radio (travel and mains versions), the quality Transportable, the All in one "HiFi" and "HiFi separates".
The development of early Pye transistor sets is in BVWS "The Bulletin 2008 3" available as free download to non-members.
The German battery valve portables (often with VHF and some with HF too) first added transistors as Audio amps, then IF amp with DF97 still for VHF RF/Mixer and maybe DK96, then entirely transistor.
VHF sets in early 1960s
Early VHF models from many makers used third party Mullard or German pre-built transistor modules, e.g. Hacker RP18 using a German module and Roberts using a Mullard module.