Tremolat

Hello FrankinAu, you have in the following document, pages #7, #8 and #9, my example of the casing of my two KiwiSDRs. This can give you some ideas.

http://labroue.autreradioautreculture.com/Courdilles/KiwiSDR/Documents/Description_KiwiSDR_Tremolat.pdf

The fan (brushless) is also powered by 12-15 Volts, in parallel with the current injector in the antenna. I preferred to add copper shielding. And place the boxes in a 19-inch rack bay. The parasite spectrum obtained is on page #11 (LNA and protections are connected for this test).

Best regards, Philippe

Happy New Year to all,

Very interesting topic. My KiwiSDR #2 is in a region of France where thunderstorms are frequent (Périgord, Dordogne valley, Nouvelle Aquitaine). And the antenna is vertical, 11 meters, isolated from the ground (radiating pylon)... I placed a 0.5 A fast fuse at the bottom of the antenna. The electrostatic charge is so strong, that I often find it blown! Fortunately, I have several high-performance surge protectors of different types, two at the bottom of the antenna, two others at the arrival of the 250 meter long coaxial cable. There is also a first Unun transformer at the start, and a second at the arrival.

When the long coaxial cable arrived, just before the RF amplifier, I built myself a protection box which contains: a discharge coil, a 0.5 A fast fuse, protection diodes PR1007G in parallel, a serially wired robust capacity. The PR1007G diodes can handle peak currents of 30 A (Non-Repetitive Peak Forward Surge Current 8.3 ms). Their capacitance is 8 pF. It's simple and effective. Here is the picture :

For further information, the description of the installation : http://labroue.autreradioautreculture.com/Courdilles/KiwiSDR/Documents/Description_KiwiSDR_Tremolat.pdf

We have another phenomenon in our area : les Farfadets. It's visually stunning. Nicolas Escurat photographs them :

Farfadets : https://www.facebook.com/share/r/18QBqRmqLb/?mibextid=wwXIfr

Best regards, Philippe

Dear all,

this is why I have moved the receiving antennas as far away from buildings as possible. The antenna of my KiwiSDR #1 is 50 meters away. The antenna of KiwiSDR #2 is 250 meters away. The 75 ohm lines are buried about 40 cm. This is the only valid solution I have found to eliminate all this radio interference from domestic appliances using a switching power supply.

I also have 32 photovoltaic panels (12 kWp three-phase), which doesn't interfere with KiwiSDR reception, provided the installation is well filtered.

The neutral system on the electrical installation is IT (230 V). This means that there is no neutral and the mains power supply is symmetrical (two-phase).

I hope this helps. Happy RFI hunting. Best regards, Philippe