Chapter 3 ____________________________________________________Installation and Operation
VLF Signals
In the VLF branch, the diodes V1 and V2 after the R3 function as
overvoltage protection. After the V1 and V2 diodes, there is a low-
pass filter. The bandpass edge of the low-pass filter is at
approximately 30 kHz.
After the filter, there is a high-impedance FET amplifier V3 and V4
(2N 3819).
V5 operates as a voltage amplifier and impedance matching device.
L3 (2.2 mH) prevents attenuation of Loran-C signals, since both
amplifiers have a common output terminal X2.
Loran-C Signals
In the Loran-C amplifier branch there are voltage limiting diodes V6
and V7. C10/L6 is tuned for 100 kHz.
V9 (2N 3904) is a voltage amplifier. After V9, there is a gain control
potentiometer R10.
A1 is a linear circuit amplifier, the output of which is connected to the
transformer C21/L4 tuned for 100 kHz. The amplified Loran-C signal
goes to the output terminal X2 via C8.
VAISALA _______________________________________________________________________ 13
