====== Pre-Amplifier 14 ======
original source(([[http://en.blitzortung.org/Compendium/Documentations/Documentation_2014-05-11_Red_PCB_10.4_PCB_12.3_PCB_13.1_PCB_14.1.pdf|Documentation System RED]], chapter 4.2.3))

===== Electronic parts =====

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 {{:en:hardware:r6_8m.png?80|}} |
|  | R2 | 6.8MΩ {{:en:hardware:r6_8m.png?80|}} |
|  | R1 | 4.7MΩ {{:en:hardware:r4_7m.png?80|}} |
|  | R4 | 10kΩ {{:en:hardware:r10k.png?80|}} |
|  | R5 | 75Ω {{:en:hardware:r75.png?80|}} |
| 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

===== Connecting Amplifier PCB 13 =====

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.

===== Connecting an Antenna =====

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

===== First hardware check =====

The green LED should light slightly.

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

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