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I needed the manual immediately and I got it immediately. I couldn't find this manual anywhere else on the net. The site was easy to traverse, and the price was very reasonable. I'll definitely be back for any future needs.
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I received a good service manual, with good resolution. Improve the instructions for the purchase because they are not well understood.
For the rest, so good.
Thanks Angel.
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Very good documentation for the Grundig 2077 model (as well as similar 800/900/1000 series radios). The first two pages are a summary of reception specifications and output capability. The third page is the tuner dial indicator and dial cord routing diagram. the final ~5 pages are the schematics for the various models (including 2077). The scan quality of the schematics are good, adn can be easily read if zoomed in. The documents are in German, not English as stated. It would have been nice to have the tuning sequence and settings, and some trouble shooting materials... or component and wiring map.
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Perfect like it was descriped, Perfect like it was descriped
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Very good detail, all pages clear, exactly what I needed
VGS-1
CIRCUIT DESCRIPTION
VGS-1 IC57 O 5V O I
IC2 94 pin R17 PA1 High : Normal Low : Shift
External device 5V
XTAL
IC2 MCU C10 Q1
EXTAL 66 X1
Pull-up resistor Pull-up resistor
67
C12
R18
R19 5V
I
Q2
Fig. 4 Fig. 3 External device, pull-up resistor
Beat shift circuit
â� AI Input Port
If input exceeds 100mVp-p, the input signal is clipped and distortion occurs. It is necessary to make setting so that no signals exceeding 100mVp-p are input. If the input level lowers, S/N decreases, so the maximum input not exceeding 100mVp-p must be used.
Amateur Transceiver Identification
The VGS-1 can be set as an amateur transceiver or a Land Mobile Radio transceiver in the factory. When it is used as a Land Mobile Radio transceiver, internal data in the VGS-1 is changed to suit the Land Mobile Radio transceiver, so it cannot be used as an amateur transceiver. The VGS-1 set as a Land Mobile Radio transceiver can be identified because the RV4 land on the PCB is at High level. The default is Low level.
â� AO Output Port
When recording is performed with a 100mVp-p input, the playback output becomes an approx. 2.8Vp-p level. If Prerecorded Voice is generated, the output is approx 2Vp-p.
C11
Beat Shift Circuit
To prevent VGS-1 clock oscillation for the MCU (IC2) from causing spurious reception to transceivers to which VGS-1 is connected, the clock oscillator (11.0592MHz) has a beat shift circuit with a transistor switch (Q1).
Accessory unit Foil side view
â� Beat Shift Circuit Off
Pin 94 of the MCU (IC2) goes Low level, Q2 turns off, and
RV4
RV3 RV2 RV1
Q1 turns on because a 5V bias is applied to its base. In this condition, C10 is shorted, so the oscillation frequency is unchanged.
Fig. 5 RV4
â� Beat Shift Circuit On
Pin 94 of the MCU goes High level, Q2 turns on, and Q1 turns off because its base is pulled down to GND. In this condition, C10 is connected in series to the crystal oscillator and the oscillation frequency increases by approx. 150ppm.
3
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