17 December 2016

Review: Propagation and Radio Science Eric P. Nichols, KL7AJ

Produced with Proplab
A bridge between two worlds

The study of the subject leads to two very different worlds: the world of radio wave propagation, which is characterized by many years of experience in dealing with transceivers, antennas and the influence of the transferable knowledge from practical physics. In this way, approximations to the characteristics of the bands from the short wave to the gigahertz range are cast into easily understandable radio weather forecasts, which convey a delicate sense of security and understanding.

16 December 2016

My best Travel-Loop crafted by John PD7MAA

In former times I had severe antenna restrictions so I bought a heavy Loop and it worked. But when I managed to put some wires in the garden and the signals were about 1-3 S-units above, I switched. Beside that I was enjoyed by constantly re-tuning the antenna.

But times have changed and my experience and expectations grew. I have an EndFed hanging only 6 m above the ground between two houses ... and I wanted more. Of course there are a lot of tips and tricks in the internet how to build a magnetic loop. But I wanted to have something electrically perfect and the construction should be sturdy.

With permission of  J. Scheepers
John Scheppers was experimenting for a long time with theses kind of antennas and he reported very good results. So I kindly asked him, if he was willing to build one for me.

09 December 2016

Ionogram Dourbes 09.12.2016

Produced with DX-Tools

Pressure Measurements for CW-Paddles

Fingers are a sensible instrument, but you never know if your own fingers behave as predicted. It is easy to measure and adjust the contact gap of a paddle with a feeler gauge. But when it comes to adjusting the paddle tension your on your own ... until now.

French Dynamometer testing the Palm Pico Single

It is easy to use.

29 November 2016

Anmerkungen zu den Skimmerdaten CW Contest

Benutztes Equipment:


Der Red Pitaya (5 Band) war die meiste Zeit an eine EndFed (10, 20, 40 m) angeschlossen. Zu Zeiten an dem ich am Contest teilnahm wurde eine Breitband Aktivantenne im Zimmer verwendet. Aus Erfahrung weiß ich, dass sich weniger die Anzahl der Spots änderte, sondern die Richtungscharakteristik. Das SNR bewegt sich auf ähnlichem Level. Allerdings sind auch hier "Ausreißer" in beide Richtungen zu vermerken.


Auf 20 m und 40 m wurde die EndFed an einem Kx3 verwendet.
Auf 15 m kam eine Magnetantenne an einem Kx2 zum Einsatz, die im Vergleich 2-3 S-Stufen bessere Ergebnisse lieferte. Auf 20 m brachte die Loop vergleichbare Signale mit der EndFed.

28 November 2016

The Red Pitaya, CW Skimmer and the CQ WW DX Contest

The contest is over and my goals were fullfilled. I wanted to see if the ionograms are consistent with actual propagation compared to the collection of spots done with the Red Pitaya and the CW Skimmer Server. (See the basics in my article Red Pitaya als Funkwetterstation). Here is the hourly presentation of the second day.

Produced with ViewProp
(See the other collections in my blog below.)

26 November 2016

24 hours CQ WW DX Contest

Nearly the first 24 hours have gone by and it is obvious that for the region about 400 km around Dourbes the Ionogram could be used to predict propagation for that region.

Produced with DX-Tools
If you compare it with the real communication on the various bands, you will see that the Propagation