WINTransceiver
WINTransceiver Module Block Diagram
CPU and PLL Circuit
CPU circuit
The CPU MDT1020B (Central Prossessing Unit) is the "hart" in the transceiver module, and controls RS232 communication and the two PLL`s, Packet communication and all the switching and settings in the transceiver.
The CPU uses DS1803 Dual Digital Potentiometer to controlling the microphone volume and speaker volume, and MAX518 Dual 8-Bit DAC`s to controlling the RF-Gain and RF-Power.
PLL circuit
The PLL (Phase Locked Loop) consist of two MC145170 to controlling the RF oscillator and IF oscillator.
The IF oscillator will generate the following frequencies:
FM/AM : 10.695MHz
USB : 10.695MHz - 2.5kHz = 10.6925MHz
LSB : 10.695MHz + 2.5kHz = 10.7975MHz
The RF oscillator allways operating at:
fo = fR + fIF = fT + fIF
where
fo = Oscillator frequency
fR = Receiving frequency
fT = Transmitting frequency
fIF = Intermediate frequency
In FM Modulation mode the modulation signals controls the 10.240MHz X-Tal oscillator in the RF PLL. This signal is also used for the IF PLL and the FM IF and Discriminator Circuit.
Microphone Circuits
The microphone signal is amplified in TL084 and then passing the DS1803 Digitally Controlled Volumcontrol before its led to the active BandPassFilter.
The TxD for Packet Radio is led to the DS1803 in Packet mode, and the microphone is then disconnected.
The CD4066 Bilateral Switch is used as modulationselector, and is controlled by the CPU.
Transmitter Circuit
SSB transmitter circuit
The SSB signals is generating in the MC1496 Balanced Modulator before it`s are filtering in a narrow band Ceramic 10.695MHz filter.
In USB mode the PLL generating 10.6925MHz for the Balanced modulator, and in LSB mode the PLL generating 10.6975MHz for the Balanced modulator.
The output from the Narrow Band Filter is led to the SA602 Balanced TX Mixer and will be mixed width the signals from the RF PLL.
AM/FM transmitter circuit
In AM/FM mode the SA602 mixer is mixed with 10.695MHz from the IF PLL. The SSB parts is then disconnected.
The signal is then amplified by SA5209, where AM modulation is generating. The DAC controlling the RF Power amplification in SA5209.
RF Power Amplifier
The RF Power amplifier consist of one 2SC1966 Driver transistor an two 2SC1969 Finale transistors in PushPull configuration.
Receiver Circuit
RF receiver circuit
A received signal is amplified in BF961 Dual Gate Mosfet Transistor, before it`s led to the SA602 RF Receiver Mixer where its are mixed with the signals from the RF PLL.
The DAC is controlling the RF Gain in BF961.
FM receiver circuit
The MC3372 consist of a 10.695MHz FM IF amplifier, downconverter to 455kHz and a FM Quadrature Discriminator (Detector).
The MC3372 also generate the signal strength indicator signals.
AM/SSB receiver circuit
This IF frequency led to MC1350 AM/SSB IF Amplifier. To improve signal over load distortion which would
be caused when the receiver is subjected to a strong signal, a stages of AGC loops are provided.
The AM/SSB signals is then detected in MC1496 Product Detector.
Audio Circuits
After the TL084 PreAmplifier the audio signals passes a active PassBandFilter and led to DS1803 Digitally Controlled volume control.
In Packer Radio mode the RxD signals led to the Packet circuit, and in voice mode the audio signals led to
TDA2003 LF Power Amplifier.
