Namibian Amateur Radio Centre

Expanding the frontier of Amateur Radio in Namibia



Today 133

Week 330

Month 2625

All 186387


On our last Fieldday on the Farm Eckenberg, amongst other things, a fox hunt competition had been held. This challenge created the desire to build an own bearing receiver. So we ordered the equipment as there is a soldering station with accessories, tweezers, pliers and the electronic components to build a fox hunt receiver for 80m. 

DHPS Fox Hunt Group

After receiving the equipment the impuls to set up the electronic got so intensive that we fixed an appointment already at the next day to start assembling the receivers. This was the 2nd of August at the physics lab in the DHPS. After a short introduction into the principles of hf-receivers we started with the practicals.

We again used the circuit of Bodo Schneider (DL4CU). Six of these receivers already have been set up before in our club and all of them are working nicely to this day. Many thanks to Bodo for this effective and easy unit.

DHPS Fox Hunt Group

As before we started assembling the electronic components on a strip board. This is not so easy as soldering a printed board. The arrangement of the parts and wires have to be done by the builders themselves and here and there some musing faces could be seen. This way of creating an electronic circuit was completely new for our students. But after a while the process became easier and the primary uncertainty was blown away. At the end we could say that this afternoon brought a lot of fun to all of us.

At home the activities will go on and the boards will be assembled further on...




Tuesday, the 09.08.2011: 

The second meeting of the ARDF-Group indeed brought a big surprise to me. The progress on the boards was clearly visible, and the quality level of the work is amazing. On the picture at the right hand side you can see an already completed board. No one had experimented with a strip board before!

At this point I have to mention that the expenses for the soldering stations have already payed off. A controlled heat source is absolutely necessary for high quality solder work in electronics.

Übersicht Bauteile




Another surprise for me was the inventive talent of the course participants. We did not discuss the different types and values of the electronic components before and thus identification of the different parts was quite difficult. Especially capacitors and diodes caused some problems. These types and values are fairly variegated. This problem was solved by the students by sorting the components and taping them to a sheet of paper; thus bringing some collocation and overview into this business. With the help of the exclusion principle all parts could be identified in that way.






But this was by far not all. My favorite is a very handy device to position the solder at the correct place, whilst both hands are busy doing other things. As you can see on the picture - this can be done by the most simple means.







Platine bohren



Eventually the mechanical part of the project started. The positions and diameters of the drills in the housing had to be established. At the same time one had to pay attention to the position and space inside the housing.








Bohrungen anbringenThe cables to the potis, the push-button and the antenna coils must not be too long, and the strip board should be able to be mounted easily.











To be able to guarantee a constant and high quality standard, two very important things are compulsory:


Permanent concentration and









sufficient catering (the rest you can find outside of the picture)!








Das Ergebnis



And because all of these matters were assured, the selfmade result at the end of the day could be proudly presented.









I will keep you updated...


best 73

Wolfgang Gradewald (V51WG)




Digital filtering on 80m, further development of the squelch for short wave, and first experiences with NVIS-antenna technique.

Digital filtering of a short wave signal:
In order to reduce the noise component, and to achiev

Circuit TX


Okay, "extra mural for amateur radioing" may sound a little boring but this by far is not the case. Since 2011 this extra mural is in existence. One learns how a ra