====== E-field pre-amplifier PCB 17.x ======
original source(([[https://docs.google.com/document/d/1KzPZJW0ErInFtfTCmhNhSZTOpg6N2bgZDyIxkh_DRVs/pub?1532944531#h.iubpod4vxyrx|Documentation System BLUE]], chapter 2.2.3))

The E-field pre-amplifier board PCB 17.x has the following THT components whose placement is obvious.

^ image ^ count ^ part ^ note ^
| {{:en:hardware:blue:inductor.jpg?100|}} | 1 | Inductor - 3.3 mH | Taiyo Yuden |
| {{:en:hardware:blue:akl_101_02.jpg?100|}} | 1 | Header 2-pin, Pitch 5.08mm | |
| {{:en:hardware:blue:f-connector.jpg?100|}} | 1 | F-Connector, PCB mounting | |

At panel PCB 20.1 and subsequent panels the free board space next to PCB 17.x is used as an experimental electrical antenna. This antenna is designed only for testing purposes. Due to a small manufacturer's breakdown on Panel 20.5, the printed circuit board next to the E-field preamplifier is not connected to the input of the E-field preamplifier. Here, either a small solder bridge must be set or a corresponding antenna must be connected to the input. You can also break off this aerial and connect a wire antenna at the two pin header. The external connection point is ground, the central connection point is the antenna. Note that any electrical antenna must be placed outside far away from from buildings and electrical interference sources.

{{:en:hardware:blue:coax.jpg?200|}}\\
The E-field pre-amplifier is connected with 75 Ω double shielded coaxial cable to the main board. The cable may have a length of up to 100 meters. The ends are attached to F-connector.

When the pre-amplifier is powered, the red LED should light. At the early pre-amplifier board 16.1 a green LED probably lights very weak at a supply voltage of 3.3 volts. However, this is not a defect but normal.