What is stereo?




There are now two system of high fidelity, monophonic (monaural) and stereophonic. Monophonic is a system that starts from one microphone and is fed through a single high fidelity set. Stereophonic is a double system. Two separate microphones are placed at different sides of the orchestra and two different systems are used to keep the two signals or channels separated. Two separate speakers are used, placed on different sides of you room. Stereo is much like 3-D photography, two slightly different sound reach your ears giving you a new dimension in sound.



H.H. Scott '59





Heathkit AR-1515

From its half-inch tall LED frequency readouts to its extraordinarily low distortion, the Heathkit AR-1515 is the finest receiver heath has ever designed.
The Ar-1515's digital Readout is far more accurate thas dial-type tuning. Simply tune to the exact frequency you want. Signal-strength and center-channel meters then help you "zero in" on the strongest signal and lowestFM distortion. There's even an oscilloscope output to monitor multipath distortion.
The amplifier section meets the same high standards. That extra margin of performance assures clean, wide-range sound without audible strain or struggle on even the most complex musical passages. And you'll hear the music over a background of silence - hum and noise are 65 dB below full output in phono and 80 dB below full output on high-level sources.

The amplifier section is also unmatched in convenience. All the frequently used controls - volume, input selector, stereo/mono switch, tuning - are on the front panel. The secondary controls are concealed behind a hinged door. Convenient indicator lights on the front panel show, the input you've selected. The digit light only when listening to AM or FM and only the necessary tuning meters are illuminated - signal-strength only for AM, signal-strength and center-tune for FM.
The bass and treble controls act primarlly at the frequency extremes to compensate for room acoustic and program deficiencies while maintaining smooth midrange response. And the AR-1515's  preamp out/amp injacks allow it to be used with any audio equalizer, such as the Heathkit AD-1305.

The AR-1515 is even easy to build. Obviously the AR-15151 is a complex and sophisticated receiver, but its well thought out, modular design and color-coded wiring harnesses simplify assembly

Specifications
Amplifier Section
Frequency Response:  8 Hz to 45 kHz (+0 -1 dB);  4 Hz to 80 kHz (+0 -3 dB)
Intermodulation Distortion:  less than 0,08% (from 0,25 to 70 watts, full output)
Damping Factor:  greater than 60
Input Sensitivity:
Phono 1 , 2 :  2 mV
Aux, Tape , Dub. :  200 mV
Input Overload:
Phono :  greater than 100 mV
Aux, Tape,  Dub. :  greater than 10 V
Hum and Noise:
Phono (2 mV reference) :  --65 dB
Aux, Tape, Dub. (200 mV reference):  -80 dB
FM Monophonic
Frequency Response:  20  - 15,000 Hz  ±1 dB  
Antenna:  75 Ω or 300 Ω
Sensitivity:  1,8 µV
Selectivity:  100 dB
Image rejection:  90 dB
Mute Threshold:  0 -5 µV variable
FM Stereophonic
Channel Separation:  40 dB or greater at mid-frequencies;  35 dB at 100 Hz; 20 dB at 10 kHz; 20 dB (Nominal) at 15 kHz
Harmonic Distortion:  0,35% with 100% modulation
19 and 38 kHz Suppression:  60 dB
SCA Suppression:  60 dB
 AM Section
Sensitivity:  5 µV with 50 Ω direct input
Selectivity:  200 dB at 10 kHz
AM Antenna:  external static-shielded loop
Image Rejection:  70 dB at 600 kHz, 50 dB at 1400 kHz
General
Accessory AC Outlets:  One switched and one unswitched
Power Requirement:  120/240 V AC,  50/60 Hz
Dimensions (W x H x D):  21-1/2" x 6-3/16" x 15"
Weight (net):  35,8 lbs

2 commenti:

  1. Unknown6 novembre 2021 alle ore 19:53

    I finished my HEATHKIT AR1515 in begin february 1981. So I replaces my AR1214 by this big receiver I also had the audio processor AD1304, the equaliser AD1305, control center AD1307 and the audioscoop AD1013.
    So together with a huge FM antenna on a mast and rotor, I had good control and receptions of all stations.
    The installation was working at least 15 hours a day, because my wife didn't work outsite and the sound of the televion went true the receiver too. I had also an AA1219 extra amplifier to feed extra smaller speakers in the kitchen, all of it from Heathkit, also the biggest speakers in the living.
    after my wife died in 2000 the receiver was no longer working 15 hours a day of course and last but worst I had to move because a lot of problems.
    The receiver had of course a few defects during the years, such as a broken elco in the preamp board and later a defect in de counter circuit. and a defect relais in the muting circuit board.
    But all of it is repared and since I've been retired now all of it is again working the whole day.
    IT IS REALLY A MASTER PIECE TO LISTEN to.
    In 2007 I find a defect one on e-Bay, the purpose was to keep it for spare parts, but I think it is not required and I started to repair it.
    Lots of defects in the power circuit, power amplifiers etc.
    Now the only problem I have is the readout. After 99.9 the readout switches to 180.1MHz, so 102,9MHz read as 182,9MHz.
    Idem on AM, the same problem after a certain frequency.
    I hope to solve this problem too, but it is not easy.
    If it is solved I can sell it again on e-Bay.
    I also will replace the display bulbs by LEDS's as I did with my own since these lamps are difficult to find and also difficult to replace.
    But: there is nothing better then a Heathkit product.

    RispondiElimina
  2. Murrayatuptown8 gennaio 2022 alle ore 03:50

    Visitando tramite Google Translate... qualcuno può confermare che il p/n del trasformatore di alimentazione Heathkit AR-1515 è 54-916? Grazie.

    RispondiElimina

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