The active antenna mini-Whip 10 kHz - 30 MHz
This is modification of miniWhip by PA0RDT. But I used low-noise MOSFET BF998 and UHF transistor BFG591 ( or russian VHF transistor KT606, KT922, KT913).
Gain of amplifier on BF998 is 20 dB
The antenna is made in the sanitary tube diameter 50 mm and length 210 mm
Power supply: 9-15 V
Сonsumption current: 90 mA
Output resistance - 50 Ohm
Power is supplied via a coaxial cable using power feed unit
RF isolating transformer reduces the noise level and increases the S/N level.
Update 8 February 2016:
New PCB for mini-Whip from Singapore
UPDATE from 2 Dec 2016
New version of mini-whip with a top connector. Now you can connect any wire to the active whip. That's need if you want more sensitivity!