Montag, 29. September 2025

coffee can antenna - 2m tuned lamda/2

This fantastic antenna was featured in the May 1983 issue of "73 Magazine," pages 54-55. 

Assembly was straightforward and problem-free.
 
 
   
 
 

 

Freitag, 26. September 2025

"Pressespiegel" - Box

 

RAI Südtirol always broadcasts the reviev of the newspapers at a time
when I'm on my bike cycling to the office. 
Since this "voice recording module" has recently become available that can record
17 minutes, I built this box, together with an Arduino UNO, a HW-84 real-time clock, and a TEA5767 FM radio module, 
which always plays the latest "press review" at the touch of a button.
 
 

 
 

 

Donnerstag, 11. September 2025

Measuring the "FM band stop filter"

 

I quickly tested the MRDDZ BS "band-stop filter." The results weren't satisfactory:
 
                                        Measuring only the throughpass
  Marker 2: 150 MHz 
                   no 2m amateur radio - no AIR-band - no 136 WX satellites ...
88,5 MHz: -11,4 dB / 108 MHz: -21,4 dB