#OLD TRANSISTOR RADIO GREEN SERIAL NUMBER#
#OLD TRANSISTOR RADIO GREEN SERIAL#
#OLD TRANSISTOR RADIO GREEN DRIVER#
#OLD TRANSISTOR RADIO GREEN SERIES#

#OLD TRANSISTOR RADIO GREEN SERIAL#

My unit - perhaps one of the oldest transistor radios in the world (based on the low 2076 serial number) - required careful handling. None are really expected to operate, only to ‘show’ in collections. A rare pearlescent blue unit sold in 2000 for $3,200.

AssessmentĪ Regency TR-1 in average condition usually sells for several hundred dollars on auction sites. A schematic of the TR-1 is shown in Figure 3 with the four electrolytic capacitors highlighted (more on this later) the chassis of my unit is shown in Figure 4.įIGURE 4. I decided to restore it just so I could hear how it sounded.

Like most of the TR-1 parts, it was probably the smallest speaker Jensen made at the time. The speaker in the TR-1 was a 2.75” Jensen - larger than most of the ‘60s pocket radios - so it might sound okay.

#OLD TRANSISTOR RADIO GREEN DRIVER#

The 1954 TR-1 had only four transistors with a single audio stage driving the speaker, while the later six-transistor units invariably had an audio amp stage following the volume control and feeding push-pull outputs through a driver transformer. Starting around 1960, the market was flooded with six-transistor pocket radios - with many of those made for American companies.

#OLD TRANSISTOR RADIO GREEN SERIAL NUMBER#

The question really was never answered because the actual production serial number on the commemorative TR-1 they found was not revealed.Īfter having the radio featured on the program, I started to wonder what it actually sounded like 62 years ago. The question for the ‘detectives’ was whether this was the oldest transistor radio in existence.

#OLD TRANSISTOR RADIO GREEN SERIES#

The radio I’m restoring in this article ( Figure 2) was featured on an episode of the PBS series “History Detectives.”

There are a number of good websites to learn the history of the TR-1, and one of the most complete is The site is run by Don Pies, the son of Regency co-founder John Pies. Early advertisement for the TR-1.ĭespite its high price, Regency sold the first run of about 100,400 TR-1s before introducing the TR-1G (which was re-designed with a PNP output transistor) in 1956. An early advertisement is shown in Figure 1.įIGURE 1. Options included a leather case for $3.95 and an earphone for $7.50. Of course, the battery was “not included.” The TR-1 pocket radio was introduced just before Christmas 1954 and sold for $49.95. (Industrial Development Engineering Associates) of Indiana to produce the first transistor radio under their Regency brand. The main benefits of the devices were their small size and low power requirements, so they decided a transistor pocket radio would be a good product to introduce the technology to the public. Secondly, the actuation of the eye might not work due to a bad 1 meg resistor usually hidden inside the eye tube socket across pins 2 and 4.When Texas Instruments developed a process to mass produce transistors in the early 1950s, they wanted to show the advantages over tubes to spur marketing. There is no way to rejuvenate these eye tubes but you can make a dim one brighter by slightly increasing the filament voltage if possible. First, dim image which is a function of how many hours the tubes been on. There are two common issues with the operation of these. The 6T5 has just a little pin in the center and it operates liike a camera iris. These all have the silver button in the center of the eye and show a pie shaped image when operating. There is a 12V filament version with and octal base ( the 1629 type) which was often used in test gear, its cheaper and so there are adapters to use it in place of the others. Not really, the images on the 6E5/ 6G5 / 6U5 all match but the 6E5 is the most sensitive. Is there a way to tell them apart visually? I have a GM branded 6?5 tube here that I tested as a 6E5, guessing about it.

Old transistor radio green