What type of battery is used?Battery type 18650.Does the receiver have a controller for charging the battery?Yes, a built-in controller is available and provides full charge control.Can the device only work from USB?A built-in battery is recommended even when powered by USB.What type of 18650 battery to use - with or without protection board?The type of battery holder used does not allow the use of batteries with a protection board. they have large dimensions.How to choose a battery?I recommend using batteries with a capacity of more than 1500mAh. But keep in mind that there are many fakes, the maximum capacity for 18650 batteries is 3300mAh. If a capacity of more than 3300mAh is indicated, this is definitely a fake! Try to use batteries from reputable manufacturers – Samsung, LG and the like. Please note that batteries with a large capacity are also good weight – if the battery has a 3000mAh capacity according to the designation, but weighs less than 50 grams – this is a fake!What type of antenna do you recommend?As a telescopic antenna, I recommend using antennas with a length of about 1m or more. This will ensure the reception of HF, SV, LW and will even be acceptable for VHF. On VHF, it may be necessary to use shorter antennas.What is an attenuator and what is it for?The attenuator is designed to protect against overloading the radio.An attenuator may be required:if you are receiving a very powerful station, the reception of which will overload the radio there is a strong interfering signal near the received signal the receiver contains any spurious signals caused by strong radio signals. An attenuator value of 0dB corresponds to no attenuation (attenuator is off).What is HiZ input?Telescopic short antennas at frequencies up to 30 MHz have a high input impedance (hundreds of ohms and above) and when connected to devices with an input impedance of 50 ohms, good reception will be impossible – 50 ohms will bypass the antenna.Why do I need to switch the type of antenna input?This function is only needed to receive signals with a frequency of up to 50MHz.HiZ is needed when using short telescopic or wire antennas, for example, with a length of about 1m.The 50 Ohm input is recommended for use with long antennas, for example, dipole type, inverted V, the length of which is units and tens of meters.How long does the battery last in the radio?It all depends on the capacity of the battery and the operating modes of the receiver.For example, for DSP1 and DSP2 models, when listening to headphones, a 1500mAh battery will last for at least 4 hours.Where can I see what kind of firmware I have?The firmware version has a designation like “X.YYZ”, where X is the receiver version (1 – for DSP1, 2 – for DSP2), YYZ – alphanumeric designation of the firmware version. For the DSP1 model, the receiver firmware version is indicated on the start screen. If it is not indicated, then you have a test version or version 1.10C. For the DSP2 model, the receiver firmware version is listed in the HARD menu.Does the receiver ship with the latest firmware?The receiver is shipped with the latest firmware at the time of manufacture of a particular receiver. The update can literally come out during the delivery of the receiver. User can upgrade the firmware by themselves.How do I update the firmware?In our section Documentation there is a user manual and video instructions for the firmware.What type of RF connector is on the receiver?SMA femaleThe DSP1 receiver version does not accept the 250-400 MHz range, can this be somehow solved?This is a hardware limitation and cannot be solved in software. In the DSP2 version, reception of this frequency range is possible.Can the receiver fit multiple batteries into the radio?Yes, it is possible. The receiver allows multiple batteries to be installed. For this, the batteries must only be connected in parallel! This will increase the charging time.What is the current used to charge the battery?Charging current 0.9AHow long does it take to charge the battery?The charging time depends on the capacity of the battery. The approximate charging time can be determined by dividing the battery capacity by the charging current. For example, the battery capacity is 1800mAh, then the minimum charging time will be 1800mAh / 900mAh = 2 hours.