Arthur H. Radford
28 Bedminster Parade, Bristol, 3. (1947)

Cabot Radio Co. Ltd.
28 Bedminster Parade, Bristol, 3. (1949)

Radford Electronics Ltd.
4 Acramans Road, Southville, Bristol 3. (1953)
149 Newfoundland Road, Bristol 3. (1954)
Ashton Vale Estate, Bristol 3. (1959)

Radford Audio Ltd.
Ashton Vale Road, Bristol BS3 2HZ (1977)

Woodside Electronics
Kimberley Road, Clevedon, Avon BS21 (1989)

Arthur H. Radford founded Radford Electronics in 1946, initially producing amplifiers for PA systems before expanding into high-fidelity audio equipment. The company gained a reputation for producing amplifiers with exceptionally low distortion, leading to the development of their test equipment and the release of critically acclaimed products like the STA range of amplifiers in 1961. 
After Arthur Radford's retirement in 1989, the company ceased operations, but its legacy continued through Woodside Electronics until 2004, and today, Radford Revival, a small UK-based business, carries on the tradition by replicating classic Radford amplifiers.

Early History of Radford Electronics (1948–1954)
Radford Electronics, founded by Arthur Hedley Radford, began as a small enterprise in Bristol, England, shortly after World War II.

Arthur Radford was born in 1914. He studied at the Merchant Venturers Technical College and Bristol University. He developed an interest in electronics at an early age, getting his radio amateur license (G6YA) in 1930. He sometimes said that the “YA” in this stood for “Young Arthur”! He also became involved in the manufacture of audio amplifiers, microphones, loudspeakers, and public address systems.

During the Second World War, he spent time working on communications and military projects. When the war ended there was a flood of ‘surplus’ equipment that came onto the market, and many of the people who left military service did so with a knowledge of electronics combined with an interest in building their own radio and related equipment.  Realising this, Radford set up a shop called Cabot Radio in his native Bristol.

The company evolved from selling surplus electronic components to manufacturing high-quality amplifiers and transformers. 

1948: Founding and Initial Activities

• November 1948: Arthur H. Radford, operating under his own name ("Arthur H. Radford (G6YA), AMIEE"), advertised surplus WWII transformers. His business was located at 28 Bedminster Parade, Bristol.
• December 1948: Radford expanded his offerings by advertising surplus U.S. military 25 W Keyer amplifiers. These were modified for civilian use, capable of working with a microphone or gramophone, and included transformers to adapt from 110 V to 230/240 V mains.

1949: Transition to Cabot Radio Co. Ltd

• May 1949: Radford announced that he would continue offering surplus electronics under the new business name "Cabot Radio Co. Ltd," still based at the Bedminster Parade address.

1950: Entry into Television Equipment

March 1950: Cabot Radio began manufacturing television pre-amplifiers designed for the Birmingham frequency. These were two-stage, high-gain, low-noise amplifiers with a bandwidth of 3–4 MHz, powered by AC mains. They were marketed as ideal for long-distance reception using standard receivers.

1953: Establishment of Radford Electronics Ltd

• Around October 1953, advertisements for "Radford Electronics Ltd." appeared in trade magazines. The company had relocated to 4 Acramans Road, Southville, Bristol.
• October 1953: Radford Electronics introduced a high-power audio amplifier with specifications that highlighted its performance:
  • Output power: 65 W at 5% distortion; peak power output of 100 W.
  • Frequency response: 50–20,000 cps within ±0.25 dB.
  • Features included electronic mixing of two inputs (for gramophones or radios and microphones), independent bass and treble controls, and a robust design with a steel case.
  • Price: £37.10.0 (with a lower-powered model available for £28/10/0).

1954: Expansion into Transformers and Amplifiers

• July 1954: Radford Electronics gained recognition for its range of power, auto, and audio transformers. These transformers were conservatively rated and designed with modern engineering practices:
  • High efficiency and durability through varnish impregnation and dip sealing.
  • Accurate DC regulation ratings for specific load conditions.
  • Multiple primary voltage taps (104–240 V) and various finishes.[1]
• December 1954: The company manufactured its version of the Williamson amplifier—a highly regarded audio amplifier design popular among audiophiles at the time.

Rise to Prominence

In 1959, Radford marketed its first hi-fi amplifier, marking the company's entry into the consumer audio market. At the start of the 1960’s, he released the first of his ‘MA’ (Mono Amplifier) and ‘STA’ (STereo Amplifier) designs. The company quickly gained a reputation for producing amplifiers with exceptionally low distortion levels, necessitating the development of their test equipment to measure it accurately.

Key Products and Innovations
Amplifiers

1. STA Range: Introduced in 1961, alongside the DSM pre-amplifier.
2. STA25 Series 3: Received critical acclaim and became an audiophile reference standard.
3. MA and STA Series: Robust, wide-bandwidth tube amplifiers popular in the early 1960s.
4. STA15 MK3: A highly regarded stereo power amplifier.
5. STA100: A valve amplifier developed with assistance from Dave Alner and Paul Hamblin.

Transistor Amplifiers

1. SC4-10: A 15-watt transistor stereo integrated amplifier was introduced in 1965.
2. SCA30: A 30-watt per channel amplifier launched in 1968.
3. SPA-50: A stereo power amplifier with 50 watts RMS per channel and 0.02% nominal distortion.
4. "Zero distortion" series: Solid-state power amplifiers produced in the mid-1970s with distortion levels below circuit noise.

Loudspeakers
Radford, in collaboration with Dr. A.R. Bailey, developed and patented the first transmission line loudspeaker. This design formed the basis for Radford's larger speaker models, including:

1. Beaumond
2. Tristar
3. Studio
4. Studio 3605

Other Products

1. FM Tuners: FMT1, FMT2, FMT3, and later FMT45.
2. "Labpak" low voltage power supplies: Widely used in schools and colleges1.
3. Test Equipment: Low Distortion Oscillator, Distortion Measuring Set, and High Sensitivity Voltmeter.

Company Peak and Operations
At its height, Radford operated four factories in Bristol, employing 160 people. The company handled various aspects of production in-house, including metalwork, painting, printing, transformer design and production, loudspeaker assembly and testing, and PCB manufacture.

Later Years and Legacy
Arthur Radford retired in 1989, leading to the closure of Radford Audio Ltd. However, the brand's legacy continued:

1. Woodside Electronics, formed by John Widgery (a former Radford apprentice) and Mike Davis, continued producing and updating Radford designs.
2. In the mid-1980s, there was a limited production run of 100 Radford STA25 Mk. IV amplifiers due to growing demand from audio enthusiasts.
3. As of 2006, there were plans to revive the brand and begin manufacturing classic valve-based designs.
4. Currently, Radford Revival, a UK craft business, continues small-scale production, replicating classic Radford amplifiers.

Radford valve amplifiers remain highly sought after in the second-hand market, known for their classic design and exceptional sound quality, particularly when paired with challenging speakers like the Quad electrostatics.

[1] Shortwave Magazine Jul 1954, Page 271.