|
|
|
Categories
|
|
Information
|
|
Featured Product
|
|
|
 |
|
|
There are currently no product reviews.
 ;
Very quality copy of original service manual, which contains the circuit diagrams, PCB and lists of components, well as recommendation for calibration procedures of device, also everything else, that need for repair, tuning and use this oscilloscope.
All presented copies have high-resolution, so you can view all in detail.
This manual will very useful for simple owners and for repairers.
I recommend these manual, because myself is owner of Philips PM3216 and I need sometimes servicing these oscilloscope (principally calibrating).
Also, these document is an example of excellent design of technical documentation.
;
Excellent printing quality.
A complete and very usefull service manual with all details.
GREAT SERVICE AT VERY LOW PRICE!
A+++++++++++++++++++++++++
 ;
manual excelente completo , diagramas y esquemas bien presentados y buena calidad de imagen.
;
muy buen manual completo de buena calidad de impresion preciso y detallado , muy útil para la reparación.
;
The service manual is a good quality scan of the Panasonic NV-850, which is electrically identical to the Philips VR 6920, but mecanically just nearly.
TK-260G/(N)/270G/(N)
CIRCUIT DESCRIPTION
6. Control Circuit
The control circuit consists of a microprocessor (IC13) and its peripheral circuits. It controls the TX-RX unit and transfers data to and from the display unit. IC13 mainly performs the following: (1) Switching between transmission and reception by the PTT signal input. (2) Reading system, group, frequency, and program data from the memory circuit. (3) Sending frequency program data to the PLL. (4) Controlling squelch on/off by the DC voltage from the squelch circuit. (5) Controlling the audio mute circuit by the decode data input. (6) Transmitting tone and encode data.
3) Low battery warning
The battery voltage is monitored by the microprocessor (IC13). When the battery voltage falls below the voltage set by the Low Battery Warning adjustment, the LED flashes red to notify the operator that it is time to replace the battery. If the battery voltage falls even more (approx. 5.8V), a beep sounds and transmission is stopped. Low battery warning The red LED flashes during transmission. The red LED flashes and a continuous beep sounds while PTT is pressed. Battery condition The battery voltage is low but the transceiver is still usable. The battery voltage is low and the transceiver is not able to make calls.
1) Frequency shift circuit
The microprocessor (IC13) operates at a clock of 9.8304MHz. This oscillator has a circuit that shifts the frequency by BEAT SHIFT SW (Q31).
2) Memory circuit
Memory circuit consists of the CPU (IC13) and a flash memory (IC12). A flash memory has a capacity of 2M bits that contains the transceiver control program for the CPU and data such as transceiver channels and operating features. This program can be easily written from an external device. Data, such as DTMF memories and the operating status, are programmed into the EEPROM (IC10).
q
Flash Memory Note : The flash memory holds data such as written with the FPU (KPG-56D), and firmware program (User mode, Test mode, Tuning mode, etc.). This data must be rewritten when replacing the flash memory. EEPROM Note : The EEPROM stores tuning data (Deviation, Squelch, etc.). Realign the transceiver after replacing the EEPROM.
IC13 CPU IC10 EEPROM
q
FLASH IC12
Fig. 9 Memory circuit
21
|
|
|
> |
|
