Pre-Amplifier 14

original source1)

The electronic parts necessary for Pre-Amplifier PCB 14 Version 1 are listed in Tables 6. The Power LED must be a green LED, because it is used to generate a virtual ground of approximately 2.5 Volt. Other colors have different voltages.

operational amplifiers IC1 ADA4891 SMD SOI8
LEDs Power LED LED 3mm (green)
Diodes D1, D2 1N4148
Resistors, metal 1%, 0207 R3 6.8MΩ
R2 6.8MΩ
R1 4.7MΩ
R4 10kΩ
R5 75Ω
Capacitors, electrolytic, 2.54mm C4, C6 220 µF
Capacitor, ceramic, 2.54mm C7 220 nF (224)
C3, C5 100 nF (104)
C1 22 pF (220)
C2 10 pF (100)
Inductors, radial, 5mm 09P L1 4.7 mH

Table 6: The list of electronic parts for Amplifier PCB 14 Version 1, continuation

The pre-amplifier is connected to the amplifier by standard 75 Ohm coaxial cable with F-connectors. Such 75 Ohm cables are widely used for the connection of satellite dishes and other outdoor antennas. The cable may have a length of up to 300m/1000ft. Although there are big differences between coaxial cables, (woven or foil wound), most of them are suitable for our purposes. There are also very cheap window feedthrough available in various online stores. Note that the time stamp of the lightning signal is delayed if the e-field antenna is placed far away from the GPS module. The delay can be twice the distance between e-field antenna and GPS module.

The antenna is connected to the terminal block of the pre-amplifier

The green LED should light slightly.


Figure 40: The complete circuit diagram of Pre-Amplifier PCB 14 Version 1




Figure 41: The Printed Circuit Board, the Assembly Diagram, and an assembled Amplifier PCB 14 Version 1