THE TRANSISTOR TURNS 50
Figure 1. The Regency TR-1 was originally available in six standard
colors. From left to right, top to bottom: black, white,
cloud gray, mottled mahogany, Mandarin red, and jade green.
I.D.E.A. jumped at the chance to produce a transistor
radio. The target was to have the new radio on the market
in time for the 1954 Christmas shopping season. As this
was only weeks away, manufacturing the Regency-branded
radio had to be a true rush job to meet the deadline.
Engineers decided upon a case size for the new radio.
Attempts were made to refine the five-transistor circuit
designed by TI to reduce cost and ensure that the parts
would all fit in the case. One transistor was removed from
the circuit and — after much effort — engineers succeeded
in getting all parts to fit the case. An exception was a
Figure 2. Early TR-1s had no coin slot to open them with.
setscrew on the variable capacitor used for tuning — it
stuck out far enough that a dimple had to be machined
into the case to allow the back of the radio to close fully.
The result was the Regency TR-1 and it was introduced
the week of October 18, 1954, to much fanfare and press.
The radio’s sleek design was due more to expediency and
the desire to reduce cost rather than styling concerns.
After considering various speaker grille options, the
decision was made to simply drill holes in the case.
About the Regency TR-1
The TR-1 cost $49.95 — a princely sum back then. It
utilized a 22. 5 V battery, which — to my knowledge — was the
only fully transistorized radio to ever use this battery. The
radio came in six standard colors: black, white, cloud gray,
Mandarin red, mottled mahogany, and jade green (see
Figure 1). A special run of so-called “pearlescent” colors was
introduced at a $5.00 premium and was quickly dropped.
Apparently, consumers didn’t think spending an extra $5.00
to get a special color was worth it. These pearlescent colors
are extremely rare today and are sought after by collectors.
Unlike later radios, the TR-1 did not have a coin slot for
opening the case at the bottom (see Figure 2). As a result,
· For the experimenter.
· Determine surplus stepper motor specs using
simple easy to build test equipment.
· Design and build microcontroller-based control systems
(flow charts and code examples included).
· Design and build stepper motor driver circuits.
· Analyze the mechanical characteristics of stepper motor-driven devices.
· The book is full of experiments, circuits and code. $34.95
NUTS & VOLTS
P.O. Box 1414, Hayden, ID 83835
Voice (208) 664-4115 Fax (208) 772-8236
We have been selling on the Internet since 1996. We ship
the day we receive your order or the next business day.
Table Of Contents And Ordering
Information On Web Site.
Not Distributed Via Book Sellers
We accept VISA, MC, AM, DS, MO, Check
CA residents please add 7.25% CA sales tax
See our web sites for s/h rates.
PIC, PICmicro and MPLAB are trademarks
of Microchip Technology Inc.
Easy Microcontrol'n - Beginner $29.95
· Programming Techniques
Instruction set, addressing modes, bit manipulation,
subroutines, loops, lookup tables, interrupts
· Using a text editor, using an assembler, using MPLAB
· Timing and counting (timer 0), interfacing, I/O conversion
Microcontrol'n Apps - Intermediate $44.95
· Serial communication - PICmicro to peripheral chips
· Serial EEPROMS
· LCD interface and scanning keypads
· D/A and A/D conversion - several methods
· Math routines
· 8-pin PICmicros
· Talking to a PICmicro with a PC using a terminal program
· Test equipment and data logger experiments
Time'n and Count'n - Intermediate $34.95
· 16-bit timing and counting applications
· Timer 1, timer 2 and the capture/compare/PWM (CCP)
Serial Communications - Advanced $49.95
· Synchronous - bit-bang, on-chip UART, RS-232
· Asynchronous - I2C (Phllips Semiconductors)
SPI (Motorola), Microwire (National Semiconductor)
· Dallas Semiconductor 1-Wire bus