Sony ST A40
A compact FM/AM tuner with Sony's Acute Servo Lock tuning system and LED signal indicators.
Overview
The Sony ST A40 is an FM/AM tuner made by Sony. It uses the Acute Servo Lock mechanism for precise, stable FM tuning. A green LED lights at the best tuning point, with red LEDs on either side. There is also a 5-segment LED signal strength meter, a CAL-TONE circuit, and a pilot signal cancellation circuit to improve stereo reception.
Specifications
| Product type | FM/AM tuner, Acute Servo Lock FM/AM Tuner |
| Practical sensitivity | 1.8 μV |
| Stereo distortion factor | 0.15% |
| Effective selectivity | 80dB |
| Separation | 50dB |
| Power consumption | 8W |
| External dimensions | Width 430x Height 80x Depth 275 mm |
| Weight | 3.3kg |
| Original price | ¥34,000 |
Design
The Acute Servo Lock mechanism is newly developed for the ST A40. It is designed to find the lowest tuning point accurately so reception stays stable. The front end uses J-FET transistors, the IF stage uses a uniphase filter, and the MPX section uses a PLL-IC. The green LED lights at the optimal point, and the red LEDs on either side show which way you are off. A 5-segment LED bar shows signal strength. The circuit configuration is nearly identical to the ST-A40, and the front end matches that of the KT-900/990 models.
Market
A user manual and a marketing brochure for the Sony ST A40 are available through online resellers. The brochure is listed for £4.99, and the manual is offered via buyee.jp.
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