To compare with the K9AY loop i made a small active antenna
to the concept of PA0RDThttp://yu1lm.qrpradio.com/pa0rdt%20whip.pdf
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 heard OK2BVG good on 502kHz.
The higher b…
to the concept of PA0RDThttp://yu1lm.qrpradio.com/pa0rdt%20whip.pdf
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 heard OK2BVG good on 502kHz.
The higher b…