Vectronics VEC-1402DK - Manual (Page 20)

VEC-1402DK Instruction Manual High Performance 2 Meter Pre-Amp Kit
18
Feeding Balanced Antennas with the Balun:
Connect points W1 and W2 on the preamp directly to the antenna feedpoint
without grounding either one. If your box is metal, neither lead should make
electrical contact with it, or the choking action of the balun will be defeated.
Installing the VEC-1402DK in a Radio (and other considerations):
You may install the VEC-1402DK into a VHF receiver, scanner, ham radio
transceiver, or repeater. Use short lengths of RG-174 cable for the RF
connections. The preamp requires a 9 to 15-volt DC power source at
approximately 8 mA, which can usually be borrowed from a convenient point in
the receiver.
Warning: The preamp must never be installed in line
with a transmitter or severe damage may
result!
In a transceiver, you must install the VEC-1402DK between the antenna switch
(pin-diode or mechanical relay) and the radio's receiver circuitry. Amateur radio
Dxers who require a remote antenna mounted receiver preamp must provide
sequenced RF protection to bypass the preamp during transmit periods.
External Power Sources:
Your preamp may be powered from any suitable 9 to 15-volt DC source--
including a "wall cube" type supply. However, use caution! The actual voltage
output of a low-cost adapter may be much higher than its rated value when
powering low-current loads. This can damage your preamp. Choose a wall cube
that's both internally regulated and filtered. Models used for charging nicad
batteries may supply pulsating, unregulated and unfiltered DC voltage.
Reversing the voltage polarity of your preamp’s power source could destroy Q1.
A diode in series with the (+) power lead will prevent such damage. This
"protection diode" prevents current from flowing in the wrong direction (a diode
may also be installed in series with the 2.2-uH choke in the bias-T to protect
remote preamps).
1N914 or 1N4001
+
-
Preamp