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Soon, the FCC will open two new amateur bands- a Low Frequency (LF) allocation of 135.7 to 137.8 kHz (2200 meters) and a Medium Frequency (MF) allocation at 472-479 kHz (630 meters).  

Before FCC grants these allocations, several issues remain including noise, permitted power, antenna limitations and equipment design. These bands will be shared with unlicensed Power Line Carrier (PLC) systems that control electric grid systems.  1  

Locally, JEA does not use PLC.  These pending new bands led me to do some research about longwave radio.  My Kenwood transceiver receives down to 60 kHz but I do not think its sensitivity is very good below 530 kHz.

Through a lot of power line and electrical noise, I am hearing a beacon station on 344 kHz transmitting “JA” in CW from the Dinsmore area near Jacksonville International Airport. 

There is also strong hum at S9+30dB on 70 kHz and S9+20dB on 123 kHz caused by my HP desktop computer.

NorthCountryradio.com offers a low power, FCC Part 15 AM transmitter that covers 150 to 1710 kHz with a 100 mW output.  2

I did not see any commercially-produced transmitters for non-broadcast use offered for sale on the internet.  When amateur radio operators are granted privileges on these bands, equipment will soon follow.

According to answers.com, before 1924 all transmitters were longwave using the band of 148.5 to 283.5 kHz. Spark gap transmitters were used prior to World War I. General Electric developed powerful alternators just prior to the war.

Propagation was not understood until shortwave Amateur operators in 1923 and Marconi in 1924 experimented with longwave.    

After 1924 longwave communications began a decline because shortwave transmitters became less expensive.  3

In Europe, the former Soviet Union, Mongolia, Algeria, and Morocco--148.5 to 283.5 kHz is used for AM broadcasting.

Longwave usually refers to this range but others may refer to any frequency below 535 kHz as longwave.  Non-directional beacons transmit continuously in North America as radio direction finder systems for marine and aeronautical navigation between 190 to 535 kHz.

Time signals are transmitted to radio clocks between 40 and 80 kHz. Longwave is the most accurate for clocks because signals travel direct using groundwave rather than sky wave.

In North America during the 1970’s, frequencies of 167, 179 and 191 kHz were assigned to the short-lived Public Emergency Radio Service. There is a You Tube video about WGU-20 which is the last of the Public Emergency Stations. 4  

Today 136 kHz and 160-190 kHz are used for LowFER amateur and experimental stations.  The United Kingdom, Russian Federation, United States, Germany and Sweden use frequencies below 50 kHz for submarine communications. 5  

The Longwave Club of America has an excellent webpage with very detailed information. 6

Noise from power lines, electrical devices, thunderstorms, and motors can be a problem for longwave.  Reception is best on winter nights.  Because of the wavelength on these frequencies, the longer the antenna, the better.  Dxing.com provides the following excellent reference material:  7

Below 155 kHz high transmitter power is required. RF penetrates seawater well.  US Navy navigation systems use 10.2, 12, and 13.6 kHz; Russia is on 15.6 kHz.  US Air Force has FSK-based stations on 29.5 and 37.2 kHz to provide a backup in case nuclear explosions render the ionosphere unusable.

In the US, the Air Force uses 150 to 175 kHz for its Ground Wave Emergency Network (GWEN).  It is a packet-based network to provide communications during a nuclear war.  Transmitters are kept continuously operational on a standby basis and loud raspy bursts can be heard.

155 to 281 kHz:  An AM band in Europe with many high power transmitters at 1 million watts or more. 

160 to 190 kHz in the US is open to unlicensed experimental transmissions with transmitter power limited to one watt with maximum antenna length and feedline no more than 50 feet.  

200 to 430 kHz: Used primarily for navigational beacons with Morse code IDs. 

430 to 500 kHz: Used for Morse communications between ships and sea-to-shore.  Shore stations use 3-letter calls and ship stations use 4-letter call signs.  The number of stations using these frequencies is declining due to the increased use of shortwave and satellite communications.  After 1999, radio operators skilled in Morse code were no longer required on ships 
sailing in international waters.

500 to 520 kHz: Used for miscellaneous beacons and stations.  518 kHz is used for maritime safety and navigation information via FSK. Known as NAVTEX,  it includes weather bulletins and notices of overdue and missing ships.

If your radio tunes the basement band, listen during these winter nights and see what you can hear.

References: 
1   ARRL Newsletter July 2, 2015

2   NorthCountryRadio.com:  Low power transmitters.

3   Answers.com:  What is longwave radio

4   You Tube: WGU 20  The Last Radio Station

5   Wikipedia:  Longwave

6   Longwave Club of America

7   Dxing.com

Other references: 
Dxinfocentre.com: William Hepburn, North American and Caribbean Radio Beacons LF/MF
You Tube: Longwave Antenna Tuner
You Tube: Longwave Transmitter (tutorial and schematic on building LW transmitter)

FINAL NOTES: There is a musical group called Longwave Band. Sometimes the term loFERS means Low Frequency Band (LF). Basement Band is used sometimes to refer to both LF and VLF (Very Low Frequency Band).

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