LITTLE L-PER PORTABLE DIRECTION FINDER
The LL Series Little L-Per Portable Direction finder is a compact, hand-held, synthesized receiver with tunable, folding antennas capable of receiving both AM and FM signals. The sealed case is high-impact plastic and all exposed metal is stainless steel for corrosion resistance. A finger-operated, gasketed plug allows for the AA batteries to be quickly replaced. External antenna jacks allow for connection of L-Tronics magnetic, flexible, and aircraft antennas, as well as other antennas such as beams. A third connector on top of the receiver is used for external DC power input (6-28V) and audio output.
The DF Display shows direction and signal strength simultaneously. In the right picture above, strength is shown both on the tall bar on the left side and in half dB steps by the bold numbers. The cross on the right side of the display is indicating a signal from the left of the operator along with the operating frequency, battery condition and an external antenna connection. The picture on the right below shows a mobile setup with a strong signal coming from in front of the car. The display is transflective so it can be read in direct sunlight. At night, both the display and the keyboard are lit by LEDs and fiber optics.
The receiver is pre-programmed with 121.5 MHz, 121.775 MHz, 243 MHz and the marine calling frequency 156.8 MHz. These frequencies cannot be changed or accidently erased. Six additional memories can be programmed by the user from the keyboard. (For special applications, the pre-programmed frequencies can be changed at the factory.)
The stainless steel antennas and the handle fold up so the receiver can be placed on a car or plane dashboard or packed easily in a backpack. Batteries are replaced through a finger-operated plug on the right side. The case is sealed and designed for up to 15,000 feet altitude or 9 foot immersion in water, and a 20 to +60 deg C temperature range. It will float.
Direction finding techniques are much the same with this equipment as they are with the older style LH Series Little L-Per with these improvements:
It is not necessary to change the built-in antennas when changing frequencies. Our external DF antennas are automatically selected when they are plugged in. Specialty antennas may be selected from the keyboard.
The display shows left-right homing AND signal strength (by number and bar scale) simultaneously
The receiver can be set to any frequency in 100 Hz steps from 108 MHz to 174 MHz and 215 MHz to 270 MHz using the panel keys.
The new L-Per has a stable logarithmic or "linear in dB" receiver and the display shows strength both as a moving bar and a number between about 375 and 850 (to avoid confusion with compass directions).
The new unit uses widely available alkaline, NiCd, NiMh, or some 1.5V lithium AA size batteries. Some 3V lithium batteries will fit into the receiver but they will cause overheating and possibly permanent damage. DO NOT USE THEM! To avoid corrosion, remove the batteries when the receiver is not in use for an extended period.
The DF is not field repairable but has a built in test function. Pressing the CAL key will cause an internal calibrator to align the receiver and antennas when needed and give a "fail" message if the unit is not working properly.
The unit has an Automatic Power Off (APO) function which will turn the receiver off if no keys are pressed for either 15 or 60 minutes, as selected by the user. The APO feature can be turned off and is automatically disabled while using external power.
A Beat Frequency Oscillator (BFO) function allows unmodulated (carrier only) signals to be heard and can give a small improvement in the ability to hear very weak ELT/EPIRB signals.
While the unit is capable of receiving 215 MHz, it will not presently track the "Project Lifesaver" or animal tracking transmitters.
Accessories for the LL Series Little L-Per DF include a carrying case, two styles of power / audio cords and a mounting bracket, as well as magnetic, flexible and bent whip antennas for mounting on vehicles and aircraft .
The LL Series Portable Direction Finder Operating Manual, sent with each unit, contains complete operating instructions. Download manual PDF (400kb)
Size, antennas & handle folded, including projections: 13.4in L x 3.34in H x 3.1in D (34cm x 8.5cm x 7.8cm). Height with antennas open 24.3 in (62cm). Weight, with batteies 29oz (824gm) Receiver bandwidth 7.5 kHz. Spurious & image rejection >60 dB. Minimum usable signal <0.15uV. Detection : AM, FM or BFO selectable. Tuning resolution: 100 Hz Audio output 0.3W Power: 6 x 1.5V AA cells or 6 to 28VDC external. Minimum battery voltage for operation, 5.8V Case watertight, submersible to 3 meters, floats.