SALORA 1G6H CHASSIS 1G UNITS VIEW.

- STS086 FRONT KEYBOARD CONTROL AND DISPLAY.

- STB021 MAIN SUPPLY / DEFLECTION / SYNCH / EHT

- STD071 IF VIDEO

- STCC071 AUDIO IF DISCR

- STEE71 with TDA2840

- STEI71 WITH TBA120U AUDIO IF

- STY071E RGB AMPLIFIER

- STU073D REMOTE CONTROL UNIT DRIVING + 2ND PROGR MEMORY WITH SAA1251 +ER1400

- STM071C ST-BY SUPPLY

- STC075C WITH AY-3-8203A

AY3-8203

AY3-8203

Miscellaneous Digital Circuit - ECONOMEGA/16ch Digital Tuning System.
General Semiconductor, Inc.

Vsup(-) Nom.(V) Neg.Sup.Volt.=0
Vsup(+) Nom.(V) Pos.Sup.Volt.=12
Status=Discontinued
Package=N/A
Pins=N/A
Military=N
Technology=MOS.

 

FEATURES:

8/12/16 Programs
3/4 Bands
10 bit Coarse-Tune
4 bit Fine-Tune
Non-Volatile Memory without battery
Auto or Manual Tuning
Auto or Manual Band switching.

DESCRIPTION
The ECONOMEGA Digital Tuning system is a three chip voltage synthesizer. The first chip (AY-5-8203) is an n-channel control chip which interfaces the remote control system, memory and D/A converter. The second chip (ER1400) is a non-volatile EAROM memory which stores the tuning and band information for 16 programs. The third chip is a CMOS Buffer amplifier/switch. This amplifies the converter output from the control chip to a fixed reference voltage and also contains the switch circuitry for the fine time slot. For detailsor] the MEM4956 D/A converier circuit and the ER1400 EAROM, refer to the separate data sheet in this section.
NOTE: 10 bits of coarse time and 4bits of fine tune does not mean the resolution is 14 bits (described later). The overall resolution is: Band 3 - 11 bits Bands 1, 2, & 4 - 10 bits.

OPERATION
1. Coarse Tune
The coarse tune resolution is 10 bits with a predominant output ripple at 3.9kHz.

2. Fine Tune
The fine tune resolution is 4 bits with an output ripple at 15.6kHz. The fine tune steps twice per second related to system clock; it does not wrap around or overflow into coarse tune. During scanning it is reset to mid range.

3. Scanning
The actual tuning rates are fixed by the Tuning Clock and may be
adjusted over wide limits. Typical figures are shown below.
(a) Normal Mode
Operation of a band button initiates scanning on the
selected band, typical scan rates are as follows:
Band
 Scan Time
1
 0.8 sec.
2
 1.6 sec.
3
 8.0 sec.
4
 1.6 sec.
(b) Constant Time Scan Mode
Operation of a band button initiates scanning on the selected band. The scan rate is a constant 8 seconds for each band.
(c) Auto Band Switching Mode
At the end of each scan the band is automatically changed in the sequence 1, 2, 3, 4. In the 3 band mode, band 4 is omitted.

4. Auto Stop and Validate
In the Normal Mode a stop is executed immediately on a positive going input transition. If validate goes positive within 256 msec the system stops, if not the scan will restart (See Fig. 1 for a suggested validate circuit). At the end ot' a band the tuning voltage goes back to zero and after a delay of 256 msec scanning restarts. In the Constant Time Scan mode in Band 3, the stop is executed on a negative going transition.

5. Manual Operation
In the Normal Mode Stop and Validate can be linked to the Band Inputs to give full manual control of the tuning operation.

6. Muting
The Muting output is active from the time that a Scan is initiated until the Validate input goes positive after a Stop command. When a program change is made the Muting output is activated. for 256 msec.

7. Tuning Procedure:
(a) 1. Select required program number (1 to 16).
2. Press required band button, scanning commences
from the station currently tuned, scanning stops at the
next station.
3. Fine tune if required.
4. Store Data.
(b) Alternatively using the circuitry shown in Fig. 2, the
following procedure is available:
1. Press Band or Start.
2. Press Store.
3. Press required program.

8. Fine Tune Resolution
When the MEM4956 D/A is used to combine the Coarse and Fine Data the relationship between Coarse Tune and Fine Tune is as follOWS:
Band 1
Band 2. 4
Band 3
1 FT step = 7.5 CT steps
1 FT step = 2.5 CT steps
1 FT step = 0.5 CT steps.

9. Additional Fine Tune Information
The fine tune output is a rectangular waveform with a frequency of 15.6kHz (system clock +128). The mark/space ratio defines the fine tune level. 16 steps being possible. The following diagram relates the binary number within the fine tune store to the output waveform. Bit width is approximately 3.8,Js for a 15.6kHz output waveform.

10. Additional Coarse Tune fnformatlon
The Coarse tune output is a rectangular waveform with a predominant ripple frequency of 3.9kHz (system clock +512). The mark/space ratio indicates the coarse tune level. The addition of a coarse tune bit increases the mark period by approx. 1.0pS for a 2.0MHz clock. There are thus 256 bits within the 3.9kHz period. This accounts for8 of the 10 coarse tune bits. The information from the remaining 2 bits (LS .Bits) is used to add O. 1. 2. or 3 extra bit periods (1.0ps) over 4 periods of the basic waveform. The complete coarse tune waveform repeats every 1 ms.


11. MEM 4956 Buller
This buffer combines coarse and fine data under the control of the Fine Time slot output from the control chip. The fine time slot controls the CMOS switch and hence the times the coarse tune or fine tune information are routed to the output filter. Note the fine tune waveform is filtered before being routed to the switch.


+ UAA1008A + MC14011UB + ER1440
it's the famous Tuning memory from MOTOROLA in the 70's and was the most reliable and efficient VST Tuning System basically bugless and was quite sophisticated since was a mix of digital tech + analog tech.

The power supply here is even unique.

It use instead of a switching transistor on primary side a switching THYRISTOR like RCA ITR17011 + another thyristor for phase regulator stage at 100HZ Freq. , stabilisation and protection features.

All functions are featured by a SALORA HYBRID ASIC LF0D151154 .




TDA2541 IF AMPLIFIER WITH DEMODULATOR AND AFC
DESCRIPTION
The TDA2540 and 2541 are IF amplifier and A.M.
demodulator circuits for colour and black and white
television receivers using PNP or NPN tuners. They
are intended for reception of negative or positive
modulation CCIR standard.
They incorporate the following functions : .Gain controlled amplifier .Synchronous demodulator .White spot inverter .Video preamplifier with noise protection .Switchable AFC .AGC with noise gating .Tuner AGC output (NPN tuner for 2540)-(PNP
tuner for 2541) .VCR switch for video output inhibition (VCR
play back).



.SUPPLYVOLTAGE : 12V TYP
.SUPPLYCURRENT : 50mATYP
.I.F. INPUT VOLTAGE SENSITIVITY AT
F = 38.9MHz : 85mVRMS TYP
.VIDEO OUTPUT VOLTAGE (white at 10% of
top synchro) : 2.7VPP TYP
.I.F. VOLTAGE GAIN CONTROL RANGE :
64dB TYP .SIGNAL TO NOISE RATIO AT VI = 10mV :
58dB TYP
.A.F.C. OUTPUT VOLTAGE SWING FOR
Df = 100kHz : 10V TYP