June 18,2023

For my VHF/UHF setup I am using a dual band Yagi antenna mounted with 20 deg elevation, beaming SSW (210 deg). The signal is fed to a dual band amplifier (DBA) from SSB electronics and split into the VHF and UHF path.

Fixed mounted VHF/UHF Yagi at 210 deg with 20 deg elevation

VHF goes to my Icom IC-9700. If not used otherwise, it is running on the 144.39 MHz APRS frequency. Signals are processed via LAN using the remote Wfview program on a Linux PC routing the AF signal to the Direwolf modem for digipeating.

The UHF signal is fed through a band pass filter to an Airspy Mini SDR. Signals are processed on a Raspberry Pi 4 running a SATNOGS client.




Bread Baking Gallery

I am baking my own bread for years already, but in the past I did it mainly with a bread baking machine using commercial yeast. In September 2017 I started my own sourdough, and over the last couple of months the breads became better and tastier. End of November 2017 I bought a kitchen machine, so that I can knead the dough with the machine. Important for a good bread is a slow fermentation of the dough. Usually it takes at least 16 to 24 hours from the first dough to the final loaf.

Potato-Walnut Bread

Light white Spelt

Continue reading Bread Baking Gallery

Server down – repairing disk drive

After more than two years 24/7 the volume on my server degraded. One of the three hard disks crashed. Luckily there is some redundancy using Synology Hybrid Raid, and I am now trying to repair the volume. 5 TB of data at risk …

Once successful, will check the defect disk. Still should be under the 3-years warranty from WD.


Project XE180 – Miniquad FPV

After I just completed my first own-built quad-copter, here a few details to share about this project. Having the DJI Phantom 2 V3 for aerial photography and a ready built 250 Storm racing drone, I was looking for a FPV mini-copter to fly indoor and outdoor, using brush-less motors and a robust carbon frame. My choice was XELITES ‘s  XE180, a 180 frame (motor to motor distance 180 mm).

Continue reading Project XE180 – Miniquad FPV

How fast can a quadcopter fly?


Racing drones are becoming more and more popular, and it would not only be interesting to know, how fast they can really go, but also which parameters have a major impact on their maximum speed. When I searched in the net, I couldn’t find clear answers and had to work out something by myself; so here is my model. To be clear, my intention is not to get absolute precise numbers, but more to understand the physics behind, and to have a tool to get realistic estimates and comparisons of flight parameters for different quadcopter models. If you are not interested in the details, just scroll down to the end of the page, where I show the final formulas and some calculated examples.

Continue reading How fast can a quadcopter fly?