GME is proud to announce that we have recently partnered with the national charity, Soldier On. What are you looking for? Learn More. View all products. News Survivor Stories Product Releases. Dealer Portal. GME Professional. New Zealand. European Union. When receiving, the diodes D and D are both reverse biased Notch Filter. This allows the received signal to flow Before the first mixer stage, the LNA output is filtered by a three from the antenna LPF through L and L to the receiver front section LC tank; the tuning voltages are also provided by the end.
Tuning Voltage - DAC. This produces different matching requirements which XF before gain is provided by the IF amplifier Q This are fulfilled by following the component changes listed adjacent also provides impedance matching between the two crystal to the circuit diagram.
The second crystal filter provides the final filtering before the second IF stage. The demodulated audio from pin 11 of U is amplified by the op-amp UA. Transistors Q R R and Q are normally switched on but can be switched off to increase the corner frequency for high speed data applications. R L In conjunction with the — from crystal XT and the integrated oscillator. The resultant surrounding passive components, a fifth order active high pass second IF is at a frequency of kHz.
This image is filtered by filter with a corner frequency of Hz is formed along with a the ceramic bandpass filter CF at pin 4 and is passed to the first order low pass filter with a corner frequency of 5 kHz. The limiter at pin 6. The limiter removes any amplitude modulation de-emphasis slope is provided by C and R The filter TR demodulates the frequency modulated signal and the Trimmer RV provides a default audio level in the telemetry audio is output at pin The IF selectivity is set by the configuration of the IF filters and Beep tones are injected before and after the volume control.
C and R partially compensate for the de-emphasis network to give a reasonably flat response between Hz and A DC voltage proportional to the strength of the incoming 1 kHz. R sets the minimum beep volume and bypasses the signal is present at pin R sets the maximum beep volume and is Indicator signal is connected to pin 92 of the CPU.
Squelch The output of the amplifier is coupled to the internal speaker and An internal gain stage in U is configured as a bandpass filter external speaker socket by C The noise is filtered by R, C, C, R and R resulting in a DC voltage proportional to the amount of Microphone Amplifier noise present on the channel, the filter peaks at around 25 kHz.
The gain of the amplifier is adjusted by RV The first two gain blocks UC and UD are configured as The thresholds for open and closed squelch are controlled by an active high pass filter with a corner frequency of Hz. This software. For narrowband models, the crystal and ceramic filters are The third gain block UA provides the 6dB per octave pre- changed for narrowband equivalents at the same centre.
Selcall tones and power amplifier by its power control terminal pin 2. The microphone amplifier operates from negative feedback loop will maintain a constant level. The final gain block is a third order low pass filter. For data Diode Detector. Revision Changes Connector J offers a wideband audio interface which is used when the radio is configured for data or repeater functionality. The The information thus far is relevant to the Rev. The Rev. It is not intended as an alternative microphone input.
If it is to be used as a microphone input, the The remote head is controlled by its onboard microprocessor external circuit should contain: U U are included on the remote unit to power the CPU and ensure that it does not turn on with a supply voltage below 4.
The high power Microphone Audio output at pin 4 of U is directed into the antenna switch and low pass filter. The microphone signal is amplified by the preamp Q and is then connected to the main board at pin 3 of connector J The connector J on the main board.
The difference of these levels is used to control the RF the two serial data lines between the main board and remote. The value stored by this register is output in serial form at pin 53 to pin 4 of U TX Main PCB This controls an onboard reference amplifier which will attenuate the audio signal as it passes between pins 1 and 2. The interrupt pin 19 is held low by 8 CPU RX transistor T2, causing an assertion of pin 55 — once initialisation TX Front Connector is complete — and therefore applying sufficient gate voltage to transistor Q1.
Front Panel Connector Remote Connector. Pins 16 and 17 select the green and red LEDs respectively. It is used in conjunction with the compact model or the base model with an RH Power is derived from the radio via pin 1 of the connector J1. The keypad is connected as a matrix in which the microprocessor scans the pin combinations in order to determine which button is currently depressed.
LS1A LS Turn off the TX and disconnect the programming cable. Any interruption will cause the software to 1. Run the TX Radio Programmer application.
This is particularly important if changing between functions PMR, Procedure telemetry and data. Setup 1. Connect the TX antenna connector to the service Procedure monitor using a good quality antenna cable. Select the MHz alignment channel. Connect the TX to the PC using the programming 2. Repeat these steps at MHz, ensuring that the control 6. Note 8. Select the MHz channel using the channel buttons.
Setup 5. Connect the TX to the service monitor using a good 6. Select the Connect the TX to the PC using the programming 8. Notes 4. Select the MHz channel. Inject a MHz carrier signal from the service monitor. Repeat these steps at , and MHz. Connect the TX to the service monitor using a good quality antenna cable. Notes 2. The injected signal can be generated using a and MHz. Input a modulated signal at the first image response of the radio.
Set the RF level to dBm. Setup 4. Connect the TX to the service monitor using a good 5. This is verified by obtaining a minimum RSSI reading. Connect the TX to the PC using the programming cable.
Note 4. Repeat these steps for the other three frequencies. Crystals and Resonators 10B Crystal 4. V Out 1. Vdd 8 Mute 2. Gnd 2. Gnd 7 Vcc 3. Collector G2 G1 2. Emitter G2 1 2 4. Front Panel Connector Antenna. Audio In U Speaker U XT TX Block Diagram. Channel Switch Push A. J Phase A. Vcc Xin 5. P85 NMI P71 RxD2 TA0in 32 99 C TX Disable 1 1 8 R C CA R
0コメント