Antenna Bias

Hi,
I have a DBSRX Rev 2.1, and I must use an active antenna that work at
5v
(max 30mA of power consumption). First of all, I try to short J101 and I
have 5V without any load, when I try to use this antenna the output
voltage
go down at 35mV. I decide to test the voltage output where the load is
made
by same resistors and I measure 4.1V with a resistor of 100KOhm, 4.0V
with
50KOhm, 0.3V with 10KOhm. I repeat all measure with an external bias
voltage
via J100 and I find the gsame values.
How can I solve the problem?

Best Regards,
Alessandro.