L-400B VLF Active Gain Antenna

L-400B VLF Active Gain Antenna
The L-400B active gain antenna is a compact 26
inch antenna designed specifically for the VLFand LF spectrum. The L-400B may be used withall receivers and converters.

Product Warranty
LF Engineering Co. warrants that, at the time of shipment the products
manufactured by LF Engineering Co. are free from defects in material
and workmanship. LF Engineering Co. obligation under this warranty islimited to replacement or repair of such products within 1 year from thedate of shipment.

The L-400B broadband design enables you toeffectively receive the whole LF spectrum from
10 kHz through 500 kHz without the need of atuner. The L-400B has very high E fieldsensitivity with the advantage of excellent BCintermodulation rejection with its sharp roll off
filter. A proprietary gain amplifier and low passfilter makes the L-400B a compact and totally
sealed probe (no whip). Theantenna is omni directional
allowing for various installation
configurations and for use as aportable antenna. The L-400B
probe is waterproof and UV
resistant.

Features
10kHz to 500 kHz
broadband coverage(no tuner required)
50 ft of RG174/U
with RCA connector
included.
No BC intermod canbe detected even
1/4 mile from a 5
kW broadcast
station operating on960 kHz
The antenna probe
is fully sealed anddoes not use a whip
antenna
Extended ESD andRF protection

For sales or return authorization, contact LF Engineering Co. at (860)526-4759. For technical support call (203) 467-3590.
LF Engineering E-mail address: sales@lfengineering.com

Mounting clamp
included
Dual source power
design: Internal 9volt battery (x2) orexternal 120 vac /12 vdc supply

L-400B Specifications

Copyright LF Engineering Co.
All rights reserved.
Printed in U.S.A.

LF Engineering Co.
17 Jeffry Road
East Haven, CT 06513

Antenna Probe Size

26 inches long, 1 inch dia.

Coupler Size

4.19"L x 2.74"W x 1.57"HFilter Rejection> 40 dB above 600 kHz

E Field Sensitivity-3 dB @ 250 kHz

Low Pass Filter Response

10 kHz to 500 kHz

IP324 dBm

Internal (E probe) Amplifier Gain

20 dB

Input/Output Jacks

RCA

Operating Temperature-250F to +1200F

Weatherproofing

Antenna probe tested to -2 atmospheres (-66 ft)

DC Power:

12 - 18 Volt, 20 ma, NEDA (2) or equivalent battery

AC Power: (included)

120 vac / 12 vdc power pack with 2.5 mm plug

Introduction:
The L-400B Active Antenna covers the full low frequency spectrum from
10 kHz through 500 kHz. A proprietary low pass filter is used to prevent
AM broadcast inter-modulation and a proprietary low noise 20 dB gain
amplifier (2 wire feed) insures ample gain throughout the spectrum. The
output impedance of the L-400B is 50 to 100 ohms, and is designed tomatch most receivers and converters in use today. The Receiver
Coupler requires two 9 volt batteries (18v) for operation. An external 120
vac / 12 vdc power supply is included for continuous operation.

2. Connect the coupler output (RCVR) to the antenna input terminals ofyour short-wave receiver with input impedance between 50 and 100ohms.
3. Route the antenna cable to your receiver. Longer lengths of cable
may be added . Connect the antenna cable to the coupler (ANT)
input.
a. Coax length may be extended 150 ft for a total of 200 ft max.
length.
4. Turn the coupler on and your receiver on. The coupler LED will lightand your system is now ready for use.

Battery Installation:
Remove the 4 Philip head screws from the four corners of the front
panel. Lift the panel/circuit board from the cabinet and install two 9 volt
batteries onto the two battery clips. Reassemble panel into cabinet. The
battery life withnormal intermittent
operation is more than
4 months.

How to Get the Most Out Of Your L-400B Active Gain Antenna:
1. Keep your antenna in the clear and above metal objects (8 ftminimum height) and use a good ground on your receiver.
2. When mounting onto a metal pole, mounting area should not exceed
the neoprene grip.
3. Use a cable strain relief (clamp, strap, tape) around the mounting
pipe and cable to reduce cable fatigue at the antenna.

AC Power Supply:
The 120 vac / 12 vdc power supply plugs into the
2.5 mm jack located on the front panel. The ac
power supply may be used even with a battery
internally connected. The 2.5 mm plug disables
the internal battery when inserted into the paneljack.
Installation:
1. Mount the antenna E probe in the clear 8 ft to 20 ft high in the clear,preferably roof height. Use the stainless clamp supplied for
attachment to a vertical support pole.
a. A support pole may be any vertical structure made from wood,
metal or PVC that is between 1 and 2 inches in diameter. You may
use an external roof structure such as the top of a TV mast or roof
vent pipe. Note: The use of a vent pipe or any other large
diameter mounting surfaces will require a larger mounting clamp.
b. The support pipe should not be attached any higher than theneoprene grip as shown in the illustration.

4. Mount your antenna away from man
made EMI such TV sets, lightdimmers and other noise generators.