All manuals and user guides at all-guides.com BLITZ MJ-398U SPECIFICATIONS GENERAL Frequency Range 245.0000~245.9875 -10℃~+55℃ Working Temperate Power Supply Requirement DC 7.2V Operate Mode Simplex or Semi-duplex ≤1.6A(transmit 4W) Current Consumption Sensitivity Adjust 2~20mV Antenna impedance 50Ω TRANSMITTER Frequency Stability ±...
All manuals and user guides at all-guides.com BLITZ MJ-398U CIRCUIT DESCRIPTION 1. Frequency configuration The receiver utilizes double conversion. The first IF is 38.85MHz and the second IF is 450kHz. The first local oscillator signal is supplied from the PLL circuit. The PLL circuit in the transmitter generates the ecessary frequencies.
All manuals and user guides at all-guides.com BLITZ MJ-398U 2) First Mixer The signal from the RF amplifier is heterodyned with the first local oscillator signal from the PLL frequency synthesizer circuit at the first mixer (T202) to create a 38.85MHz first intermediate frequency (1st IF) signal.
All manuals and user guides at all-guides.com BLITZ MJ-398U 3) UNLOCK DETECTOR If a pulse signal appears at the LD pin of U301, an unlock condition occurs, and the DC voltage obtained from D309, and C306 causes the voltage applied to the PLL-LD pin of the microprocessor to go low.
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All manuals and user guides at all-guides.com BLITZ MJ-398U 1)Memory Circuit Memory circuit consists of the CPU (U811) and an EEPROM(U821).An EEPROM has a capacity of 32k bits that contains the transceiver control program for the CPU and data such as Transceiver channels and operation features 2)Low Battery Warning The battery voltage is checked using by the microprocessor.
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All manuals and user guides at all-guides.com BLITZ MJ-398U ADJUSTMENT Required Test Equipment The following items are required to adjust radio parameters: 1. Regulated power supply Supply voltage: 5-14V DC Current: 3A or more 2. Digital multimeter Voltage range: FS = Approx. 20V...
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All manuals and user guides at all-guides.com BLITZ MJ-398U Output impedance: 600, unbalanced 10.Distortion meter/SINAD meter Measurable frequency: 1kHz Input level: Up to 40dB Distortion: 1% - 100% 11.Frequency counter Measurable frequency: Up to 200MHz Measurable stability: Approx. +/-0.1ppm 12.Linear detector...
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All manuals and user guides at all-guides.com BA TT TX Path TX/R X VCO Antenna RX Path Control e r 2SJ243 /U MC4 A PC S ense N JM2904V PLL-LD PLL-LD PLL-CS PLL-CS PLL Ci r c uit APC /Tune A PC BA TT PLL-CLK...
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