2 meters 144 MHz amplifier 500W MRF300 LDMOS
Before using the EB500 Power Amplifier, carefully read this manual and other documentation that came with your amplifier. This will allow you to reduce the risk of failure of this product. EB500 is a transistor linear VHF power amplifier designed for use with amateur radio stations. Distinctive features of the EB500 amplifier. No need to replace components due to wear.
Do not drop, or damage the case, or allow foreign objects inside - this may lead to the failure of the electronic components of the E500 power amplifier. Do not operate the power amplifier with the covers removed to avoid overheating of the device. The absence of covers disrupts the cooling system. Functional Features of the EB500 Amplifier.
The built-in potentiometers in the protection circuit and the BIAS voltage control circuit are set to the correct position during setup and testing of the equipment. Any change in the position of these potentiometers will result in the need to reconfigure the amplifier using accurate measuring instruments. Before operating the power amplifier, it is necessary to connect a load equivalent of 50 ohms, minimum 500 watts or a matched antenna with known low SWR to the output antenna connector. The operation of the amplifier without load negatively affects the operation of the output RF transistors.To obtain an output power of 500 watts, the input power level should be no more than 50 watts. It is not recommended to use transmitters with an output of more than 50 watts with an amplifier. The amplifier is designed for an impedance of 50 ohms. If the antenna-feeder devices are matched to a resistance of 50 Ohms, and the SWR on all operating ranges does not exceed the value of 1.5 to 1, then the amplifier can be operated without additional coordination. If the SWR is greater than 1.5 to 1, then the use of additional matching devices is recommended. In the output stage of the power amplifier, two high-quality LDMOS transistors MRF300AN and MRF300BN are used. The rated power of each MRF300 transistor is 300 watts. The use of high-linear transistors also allowed to obtain IMD3 -30 dbC. The process of switching the transmission in the amplifier allows the TIANBO relay a switching time of 30ms. Insure your transmitter delay is set to allow amplifier adequate time to change over to avoid hot switching. The power amplifier is equipped with special high-speed protection circuits.
PTT, connection to the housing enables transmission mode. 22-25 pin - GND, common wire. EB500 Power Amplifier Protection Circuits.If the temperature of the transistor case exceeds + 70 ° C, the bimetallic thermal switch located on the transistor case will be triggered and transmission becomes impossible, until it cools down to + 65 ° C. Protection against exceeding the maximum permissible output power. If the output power level exceeds the permissible threshold, a protection will be activated that disconnects the power from the output transistors. The P LED lights up on the front panel. A power cycle is required to reset the protection. If the SWR in the load exceeds the value of 1.5: 1, then the protection system will trigger. The SWR LED on the front panel lights up. To reset the protection, turn off the power. In case of protection operation, we recommend checking the SWR antenna and feed line. Protection against exceeding the maximum permissible current. If the current value of the output transistors exceeds the permissible threshold, a protection will be activated that disconnects the power from the output transistors.
- Band: JT65
- Supported Modes: AM
- Power: 500 W
- Brand: Unbranded