Paths to Japan this week should have a maximum usable frequency of about 23MHz.

For broadcast sound purposes, 15 kHz is often chosen as the maximum usable frequency on landlines.

Paths to Australia should have a maximum usable frequency, with a 50 per cent success rate, of about 26MHz.

The maximum usable frequency for skywave propagation is strongly influenced by sunspot number.

Changes in solar output affect the maximum usable frequency, a limit on the highest frequency usable for communications.

Maximum usable frequencies (MUFs) over most paths should be somewhat lower during May than in April.

The FOT is normally just below the value of the maximum usable frequency (MUF).

The degradation mainly consists of a reduction of the maximum usable frequency (MUF) by as much as 50%.

The program takes these geographic points, the solar flux index, propagation models, estimates F-layer maximum usable frequency and E-layer minimum.

Maximum usable frequency (MUF)

Paths to South Africa should have a maximum usable frequency of about 35MHz, but the optimum working frequency is expected to be about 23MHz.

The Maximum Usable Frequency (MUF) is defined as the upper frequency limit that can be used for transmission between two points at a specified time.

Over the years a number of personal computer programs have been written to provide quick and easy predictions of Maximum Usable Frequencies (MUF) and band openings.

Paths to southern South America should have a maximum usable frequency of about 28MHz, so Ten should open in that direction on several days, as it did this past week.

Paths to the east coast of North America, now in decline, should have a maximum usable frequency - that's a fifty per cent chance of success - of about 30MHz.

Note that due to changes in ionospheric propagation caused by changing maximum usable frequency and frequency of optimum transmission it may not be possible to receive W1AW clearly on all frequencies.

In 2011, signals traceable to China regularly sent powerful HF transmissions scanning wide ranges of HF frequencies, perhaps to determine the maximum usable frequency (MUF) or other variables.

When solar activity is sufficiently high, the MUF (Maximum Usable Frequency) rises, hence the ionisation density is sufficient to reflect signals well into the 30 - 50 MHz VHF spectrum.

Frequency of optimum transmission (FOT) The maximum usable frequency regularly drops below 10 MHz in darkness during the winter months, while in summer during daylight it can easily surpass 30 MHz.

And the enhanced x-ray radiation, which is ionizing radiation, will enhance the ionization of the E and F layers, meaning they will become more reflective to HF signals below the maximum usable frequency (MUF).

The D-layer, when present during sunlight periods, causes significant amount of signal loss, as does the E-layer whose maximum usable frequency can rise to 4 MHz and above and thus block higher frequency signals from reaching the F2-layer.

In radio transmission maximum usable frequency (MUF) is the highest radio frequency that can be used for transmission between two points via reflection from the ionosphere (skywave or "skip" propagation) at a specified time, independent of transmitter power.

Figure 44 shows the variations with time of Maximum Usable Frequency (MUF) and Lowest Usable Frequency (LUF) measured on the Essex/Devon path. In addition, signals from Svalbard, Norway were monitored for a few weeks.

As the maximum usable frequency for long distance communication seldom dips below 3.5 MHz anywhere on the planet, the main propagation barrier to long distance communication is heavy D-layer absorption during the daytime, ensuring that DX paths must be largely, although not entirely, in darkness.

Maximum Usable Frequency The maximum usable frequency (MUF) for any given transmission distance is calculated from the critical frequency by multiplying by an MUF factor which is a function of transmission distance.