Tube Stereo Tuner, made in USA by Heath Co. Benton Harbor (MI) from 1962 to 1967

Handsomely housed in a steel cabinet clad in light brown vinyl.  Charcoal gray bar on the front panel and polished trim on the edges.

Front panel, from left to right, upper level: AM tuning knob –  2 green bar-type “Eye”  AM tuning indicator – AM/FM dial scale – 2 green bar-type “Eye” FM tuning indicator – FM tuning knob. Lower level: AM fidelity rotary switch (Norm/Max) – Mode selector (FM/AM/Stereo) – Stereo indicator red lamp – Stereo phase (pull to set) – Power (Pull for power on)/AFC control(Off/Max).

AFC

Automatic Frequency Control (AFC), also called Automatic Fine Tuning (AFT), 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. (from Wikipedia)

Posizionata a mano in un involucro metallico rivestito in vinile chiaro. Larga striscia grigio scura sul pannello frontale e finiture metalliche ai bordi.

Pannello anteriore, da sinistra a destra, livello superiore: Manopola della sintonia AM – Occhio magico a due barre verdi verticali per la sintonia AM – Scala AM/FM – Occhio magico a due barre per la sintonia FM. Livello inferiore: Manopola per la fedeltà in AM (Normale/Massima) – Selettore modo (FM/AM/Stereo) – Spia luminosa in rosso di ricezione in stereo –  Manopola di regolazione della fase stereo (tirare per regolare) – Manopola accensione (tirare)/ AFC (Off/Max).

AFC

(Automatic Frequency Control), detto anche Automatic Fine Tuning (AFT) è un metodo o un tipo di circuito to mantenere automaticamente un circuito risonante sulla frequenza di un determinato radio segnale. Esso è principalmente utilizzato nei ricevitori radio per sintonizzare la frequenza della stazione desiderata.  (da Wikipedia)

Aj 32 Back OK

Back panel, from left to right, upper level: AM antenna. Lower level:  Squelch – Left channel level – Left/Righ channel outputs – Right channel level – Channel separation screw – Fuse – FM antenna – AM antenna.

Squelch

It is a circuit that suppresses the output of a radio receiver if the signal strength falls below a certain level.

Pannello posteriore, da sinistra a destra, livello superiore: antenna AM. Livello inferiore: Squelch – Livello canale sinistro – Uscite canale sinistro e destro – Livello canale destro – Vite di regolazione separazione canali – Fusibile – Antenna FM – Antenna AM.

Squelch

E’ un circuito che sopprime l’uscita di un radio ricevitore se la potenza del segnale scende al di sotto di un certo livello.

Inside view (Courtesy Mario Di Manno, Canada)
Tubes : 6C9 Twin-tetrode – (3) 6AU6 – (2) 6BN8 -(2) 6HU6 – (2) 6BA6 -(2) 12AU7 – 12AT7 – 12BH7 
SPECIFICATIONS 
( from an official advertisement)
AM Section

Tuning Range: 550 – 1600 kHz
Intermediate Frequency: 455 kHz
Usable Sensitivity (Normal position):
1400 kHz – 10 microvolts (20 dB of quieting);
1000 kHz – 15 microvolts (20 dB of quieting);
600 kHz – 400 microvolts (20 dB of quieting)
IF Bandwidth: Normal : 6 dB – 7 kHz – Maximum : 6 dB – 12 kHz
AM Antenna: Built-in rod antenna with provisions for external antenna and ground
Output Voltage (750 microvolts -30% mod.): 1 Volt
Image Rejection: 1400 kHz – 40 dB – 1000 Hz – 50 dB –600 kHz – 60 dB
Harmonic Distortion(750 microvolts – 95% Mod.): less than 1%
Hum and Noise (5000 microvolts, 30% Mod.): 30 dB
IF Rejection: 1400 kHz – 30 dB; 600 kHz – 50 dB


FM Section

Tuning Range: 88 MHz – 108 MHz
Intermediate Frequency: 10,7 MHz
Antenna: Balanced input for external 300 Ω antenna. Internal line antenna
Output Voltage (30 microvolts -30% Mod.): 1 Volt
Image Ratio (30 microvolts – 30% Mod. ,98 MHz): -45 dB
Harmonic Distortion (25 microvolts – 100% Mod. , 98 MHz): less than 1%
IF Rejection (98 MHz): -65 dB
FM Audio Response (20 – 20,000 Hz): ±1 dB
AFC Correction Factor (Full AFC): 100 kHz per volt
AM Suppression: -27 dB
Hun and Noise (25 microvolt, 30% Mod.): -48 dB
Quieting Sensitivity: 20 dB – 2 ½ microvolts;
30 dB – 3 ½ microvolts;
48 dB – 30 microvolts (max. Quieting)
FM Stereo Converter Section
Audio Frequency Response: 50 – 15,000 Hz ±2 dB
Subcarrier Bandpass: 23,000 to 50,000 Hz ±3 dB
Channel Separation; 30 dB or more at 1 kHz; 25 dB or more at 10 kHz
Hum and Noise: -55 dB relative to 1 volt output
Output Impedance (cathode Follower): Variable to 4000 Ω, each channel
Outputs: left and Right channel
Power Requirements: 117 volts, 50/60 Hz 130 watts
Export Model: available for 115 – 230 V AC, 50/60 Hz
Dimensions (W x H x D): 15¾” x 5¼” x 11″
Weight Kit: 23 lbs