|
|
|
Categories
|
|
Information
|
|
Featured Product
|
|
|
 |
|
|
There are currently no product reviews.
 ;
At first I thought there had been a mix up as I required the service manual for the cassette unit and the one supplied was for the CD unit. However when I scrolled further down I realised that both had been scanned together! This enabled me to dismantle and repair the cassette unit as intended and I also have a copy of the manual for both the CD and graphic equaliser units should I ever need them. Thanks very much for a great service.
;
Excelent service, the manual is complete, very cheap and fast
Alberto
;
The item received was as described, as expected. I was pleased with the order. Thank you.
 ;
Superb rendition. Drawings (schematics) complete and unabridged. I do a great deal of vintage audio restoration. Documentation is essential for successful repairs. I have found sources over the years that offer good documentation, but rarely all that is necessary. Owner's Manuals has filled that void with complete and legible documentation. They have narrowed my "favorites" to a more manageable collection. This Denon manual in particular contained the latest revisions level, and offered alterations favorable to updating the item. The Illustrated Parts Breakdown (IPB) was well enough detailed to simplify part symbols and physical locations. You will not be disappointed!
;
Clear and concise. Saved me a lot of time and money.
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
|
|
|
> |
|
