The Sony TFM-121 was Sony’s second FM/AM radio released in 1959. The TFM-121A listed here is its updated successor released two years later. Sony made a few improvements to this model including the addition of Automatic Frequency Constrol (AFC). A 1961 advertisement for the TFM-121A describes AFC thus «Automatic Frequency Control locks in the station, prevents fading, distortion, drifting, gives you ‘sound security’ in an emergency». I have listed the differences between the TFM-121A and its predecessor further down the page.
In my opinion this is an underappreciated radio. It has an attractive under-painted gold face and classic retro tuning dial. The SONY FM/AM badge features prominently on the smart mesh speaker grill. There is a tone switch below the volume dial, two earphone jack ports, tape/phono-in, FM/AF out. The selector on the left side can be set to either AM, FM or FM AFC. It has twin telescopic antenna that fold down into the handle. The two plastic attachments on the end of the antenna are often missing on this model. On the back of the radio there is a SONY stamp marked TFM-121 (as opposed to 121A) indicating that the same case or mold was used for both radios.
The designers at Sony clearly had an eye on the future when they created this radio as its modern good looks and styling were mirrored by many later manufacturers.
This Sony TFM-121A came to me from Dallas/Fort Worth Texas in 2007. It cost me about the same as a couple of donuts and coffee. These radios originally sold for $99USD in 1961. They continued to be sold until at least 1964 when they were advertised in The Philadelphia Inquirer with a listed price of $64USD or $39USD for an ex-demo model. It measures 9.5 x 7 x 2.5 inch / 241 x 178 x 64 mm and weighs in at 3.2 pounds / 1.45 kg. It really is an OG boombox!
The advertisement below appeared in the Los Angeles Times on the 17th of December 1961. The TFM-121A was available to purchase at $99.95, a hefty amount back in 1961. The advertisers really pushed the new AFC feature on this radio. In radio equipment, Automatic Frequency Control, also called Automatic Fine Tuning, is a method or circuit to automatically keep a resonant circuit tuned to the frequency of an incoming radio signal. It is primarily used in radio receivers to keep the receiver tuned to the frequency of the desired station. In radio communication, AFC is needed because, after the bandpass frequency of a receiver is tuned to the frequency of a transmitter, the two frequencies may drift apart, interrupting the reception. AFC was mainly used in radios around the mid-20th century. In the 1970s, receivers began to be designed using frequency synthesizer circuits, which synthesized the receiver’s input frequency from a crystal oscillator using the vibrations of an ultra-stable quartz crystal. These had a stable enough frequency that AFC was not needed.
The below text listing the very few differences between the TFM-121 and 121A is from a Sony Service manual.
The gold sticker below is positioned inside the rear cover. Below that is a sticker located on the outside of the case below the rear plastic grill. Inside you will find 12 Sony transistors. I’m lucky to have the SONY battery tube, many are missing on these radios. It has a serial number of 61713 marked ‘INSPECTED UDAGAWA’.
