Feature: 1. Application: High resistance amplifier is a kind of impedance conversion device, which can convert the higher impedance to the standard 50 ohm output impedance, so as to play the role of impedance matching and isolation, mainly used for passive antennae reception matching, suitable for donut resonance antennae, tie rod antennae, whip antennae, magnetic rod antennae and so on. 2. Parameters: High resistance amplifier input impedance is 1MΩ, output impedance is 50Ω, gain is 0dB, bandwidth is 300MHz, built in 600mAh lithium ion battery to provide long time use. 3. Compatible: Can be used for any radio receiver radio for Software Defined Radio etc, fo r malachite, for small loop antennae, for Donut antennae, for Mini Loop, radio antennae, tuning loops and other models. 4. Enhanced Performance: Higher input impedance can get as much energy as possible from the input antennae, reduce the signal energy loss caused by the unstable impedance of the input antennae, which can greatly improve the reception performance. 5. High Impedance: Since the impedance generated by LC resonance is also very high, this amplifier can be directly connected to the LC resonance antennae to obtain energy directly from the resonance antennae, which can obtain higher gain and frequency selection characteristics, LC resonance antennas including for donut antennas, magnetic bar antennas, etc. Specification: Item Type: High Impedance Amplifier Material: Metal Size: Approx. 50x45x18mm / 1.97x1.77x0.71in Input Impedance: 1MΩ Output Impedance: 50Ω Gain: 0dB Bandwidth: 300MHz Charging Interface: Type-C Charging Voltage: 5V Charging Current: 600mA Operating Time: >24h Built In Battery Capacity: 600mah Lithium Ion Battery (Built In). Package List: 1 x High Impedance Amplifier 4 x Foot Pads Note: Manual measurement please allow some error.