LF90 1 Watt LF Transmitter for 135 to 190 kHz
For Amateur Radio 136 kHz and Part 15 use in the 160-190 kHz frequency range.

 

The LF90 transmitter is a 1 watt PLL synthesized CW and BPSK transmitter covering the 135-137 kHz or 160-190 kHz ranges in 10 Hz (.01 kHz) steps. It contains a built in programmable Morse Code identifier for beacon use, or can be run in manual CW keyed mode. The keying speed is continuously variable and can be run slowly for slow speed weak signal use. The PLL synthesizer and Programmable Identifier are microprocessor controlled and programmed data is retained in EEPROM. All 26 letters, punctuation marks, numbers, and several commonly used symbols can be programmed in. No computer is needed to program this transmitter. Programming is done via a DIP switch, buttons, six LED indicators, and a simple programming routine. This simplifies field programming as no equipment or attachments are needed. Some familiarity with International Morse Code is recommended. Operation is continuous duty and power supply is 12-14 volts DC negative ground at 200 milliamperes. It can be powered by a 12-14V DC supply run from the 120 or 240 volt mains, or from a solar cell and storage battery setup for unattended operation in beacon service.

The transmitter circuit board measures 4 x 4 x 1 inch and can easily be mounted in a small enclosure for indoor or outdoor operation. RF output is nominally 1 watt into a 50 ohm load. Output stage is a MOSFET. The epoxy fiberglass circuit board is fully repairable, with most components being standard through-hole varieties. On board LED indicators visually show operating status and transmitter keying.

Applications of this transmitter include experimentation, LOWFER beacons, 136 kHz Amateur use, and other license free communications in the 160-190 kHz band.  A higher frequency version MF90 is available for 160 Meter Ham Beacon use and MEDFER 100 mW experimental beacons in the 1400-1710 kHz range.

Below is a photo of the circuit board. This transmitter is available either in kit form or as an assembled PC board unit. The LF90 kit includes drilled and screened PC board and all parts on it. Although this transmitter would normally be mounted in a weatherproof enclosure (6x6 plastic outdoor electrical box recommended) near its antenna system, for indoor use where weather resistance is not needed, the PC board will fit into our NC1550 case and is the same size as the AM88 and MPX96 circuit boards.
Please send inquiries to support@northcountryradio.com    

Price: LF90 PC board kit $139.95 USD plus Shipping and Handling (See Order Form)

Available assembled and tested $199.95

Available Extras:

12V DC Regulated Supply 120V AC input
 
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TUNEABLE LF CONVERTER    XTAL CONTROLLED LF CONVERTER     VARIOMETER
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BASIC ANTENNAS               MODULATION AM&CW            FM & BPSK
NORTH COUNTRY RADIO
PO Box 200, Hartford NY 12838-0200
EMAIL: support@northcountryradio.com        Tel 518-854-9280       Internet http://www.northcountryradio.com