CARVER TX-11b AM/FM QUARTZ SYNTHESIZED STEREO TUNER RARE EXCELLENT CONDITION 🔥

Description

VINTAGE CARVER TX-11b AM/FM QUARTZ SYNTHESIZED STEREO TUNER RARE EXCELLENT CONDITION 🔥
Excellent working and cosmetic condition. Please check the pics, you get exactly what you see.
Pictures are part of the description of the cosmetic condition.
Same-day shipping from PA.
Thank you!
Carver TX-11b
The Carver TX-11b is a classic 1980s tuner that features FM stereo noise and multipath reduction, wideband AM, and AM stereo reception.
Including protrusions, the tuner occupies 19″ × 14″ × 3⅞″. You can remove the handles for rack mounting, but the hole spacing is nonstandard. The tuner weighs 11¼ lbs and consumes 15 W.
The display is vacuum fluorescent and all controls are pushbuttons. 13 memories store frequency and mode.
Circuit
An F-connector provides 75Ω antenna input. The RF amplifier and mixer use dual-gate MOSFETs. A single tuned circuit before the RF amp and three that follow yield a flat RF passband when sweep-aligned. Although the front-end uses AGC, it easily overloads. The wide IF uses a pair of Murata SFE10.7MX-A 250 kHz ceramic filters and two adjustable IF transformers. Narrow cascades three SFE10.7MZ1-A 180s and another transformer with the wides. All filters are the blue, low-group-delay type. An LA1235 IF amplifier / quadrature detector feeds an LA3401 stereo decoder, which uses a ceramic resonator and no oscillator trimpot. Unbuffered LC ultrasonic filters drive the audio output, which high-voltage 4966 CMOS switches route. Series/shunt JFETs provide muting. Back-to-back Zeners protect the output circuitry.
AM tunes 520–1710 kHz. A 5″ × 2″ loop antenna has an inductance of 13 µH and a Q of 74 at 1000 kHz. It drives a fix-tuned RF transformer. A switchable RF attenuator made from a resistive optoisolator feeds a JFET/bipolar cascode RF amplifier. A double-tuned circuit precedes the mixer. The 450 kHz IF has two bandwidths. An LA1135 integrates several RF and IF functions, while a Motorola MC13020 provides C-QUAM AM stereo reception. The frequency response extends to 15 kHz in wide. (The tuner was designed before FCC rules limited audio to 10 kHz.) Response is 3 dB down at 5.7 kHz in narrow. An audio equalizer flattens the response. A front-panel switch invokes NRSC AM deemphasis. A 10 kHz notch filter kills adjacent-channel heterodynes, while a 25 Hz stereo pilot canceller enables deep bass response. A patent covers several of the AM circuits, including a very effective noise limiter.
The controller/PLL is a Toshiba TC9147BP. A switch on the PLL board selects 100 kHz FM steps and 10 kHz AM steps for the US, or 50/9 kHz for Europe. A switch on the main PCB selects 50 or 75 µs deemphasis. A jumper in the power supply permits 110 or 220 V operation. The supply uses three-terminal regulators.