Skip to main content


Showing posts from April 5, 2011

Made an active antenna to compare

To compare with the K9AY loop i made a small active antenna   to the concept of PA0RDT I used a strip of double sided copper  clad  epoxy print 200x30 mm. The amplifier is a FET  U310  and  2N3053 emitter follower. This small capacitive antenna  did fit in a cycle bidon (bought on the Alp de Heuz once..)  Interesting this antenna  is only picking up the Electrical-field.  It is also a good RFI sniffler. I used a relative big pickup plane of about 3x20cm  at the risk of IMD but i wanted to compare this E-field antenna on the 137kHz and 500kHz bands. It works but the DCF39 TX at 138.9 kHz is about 30B stronger on the K9AY Loop. I have to check that out the difference should not be that big. That was at the low position (top picture). I moved it on top of the house about 8m a.g.   Now DCF39 138.9 is s9+30   the difference is about 20dB in disadvantage against the loop. The high position gave 10dB more signal. I have hea


Show more