- 7 -
Low Frequency Response - Internal Jumpers
The sensitivity response of the
AVA2
system does not need to be changed for almost all
installations. However, jumpers may be required to optimize or increase sensitivity or eliminate
interference from strong broadcast stations.
Set the jumpers to the lowest operating frequency
desired only if high power broadcast interference is suspected.
Refer to
Table 1
for various
jumper settings.
For access to the jumpers, loosen the two #2 Phillips Screws on each
side of the
AVA-2
unit and remove the chassis from the bottom.
The circuit board and jumper headers will be visible as shown in
Table 1
.
The
AVA-2
has five internal jumpers that modify frequency versus gain response. The L
jumpers change the inductance values and C jumpers change the capacitance values. As shipped, all
jumpers are deactivated for full frequency coverage - 100 kHz to 30 MHz.
Frequency
MHz
Inductor Jumpers
Capacitor Jumpers
L1MF
L1HF
C1HF C1MF C1LF
3.10 *
■
■
2.90
■
2.60
■
■
■
2.40
■
■
2.35
■
■
■
2.15
■
■
2.10
■
■
■
■
1.98
■
■
■
■
1.93
■
■
■
1.85
■
■
■
■
■
1.80
■
■
■
1.65 **
■
1.40
■
■
1.30
■
■
1.15
■
■
■
Table 1 - Low Frequency Jumper
Locations and Settings
1.10
■
■
■
0.98
■
■
■
■
Installing jumpers in L1MF, L1HF or both, will configure the antenna for a sensitivity peak near the
frequencies listed. The frequency response above the peak frequency does not change significantly.
Below the peak frequency, sensitivity reduction is reasonably fast. Installing a jumper in any C1
position when jumpers are being used in L1 will move the peak response lower in frequency,
decreasing sensitivity at higher frequencies (this is not normally recommended).
* Broadcast Interference and 160 meter rejection setting - 80 Meter high pass.
** Broadcast Interference rejected high pass setting for 160 meters and above.
