LF and MF bands
These are the bands at the lowest frequencies allocated to the amateur service. They share similar characteristics of daytime ground wave propagation and night time skywave propagation, and due to the wavelengths at these frequencies, antennas require special consideration.
135.7 – 137.8 kHz
This is the lowest frequency band currently available to UK amateurs and was allocated to the amateur service at WRC-07 in 2007. Although the maximum power is restricted to 1 Watt ERP, in practice this is quite difficult to achieve given the problems of building an antenna large enough to be very efficient.
Because of the small size of the band, IARU Region 1 agreed to restrict modes having a bandwidth of 200Hz or less. Operation is usually CW or QRSS CW (very low speed CW), and narrow band digital modes.
472 – 479 kHz
This band was allocated to the amateur service at WRC-12. Although not yet released to the amateur service in all countries, UK amateurs holding a Full Licence may use the band subject to specific conditions in the licence frequency schedule.
The IARU has agreed a provisional band plan as shown below.
|kHz||472 475||475 479|
|Modes||CW||CW / Data|
1.810 – 2.00 MHz
Also known as ‘top band’, the 160m band is usually grouped in with the HF bands and is the lowest frequency band commonly in use by HF operators (although it is actually an MF band). Most commercially available HF rigs cover 160 meters and antennas, although still needing to be large to effective, are possible within typical gardens.
Propagation is limited to local contacts during the day, but DX is possible at night, especially around sunrise and sunset when world wide propagation becomes an interesting challenge for the serious DXer. Unlike the higher HF bands, long distance propagation is often better around sunspot minimum when solar activity, and therefore noise level, is lower.
160 metres is also one the HF contest bands.
It should also be noted that the maximum power on 160 metres is reduced to 32 watts at frequencies above 1850kHz.
|kHz||1810 1838||1838 1843||1843 2000|
Note that this is only an indication of predominant mode use, see detailed band plan for full definition of permitted modes.