**K5MQ**has been running

**WSPR**for 4 days at

**100 mW**output on 40 meters.

To show the behavior of the

**propagation**from day to day, I made a overview for four days.

This analysis uses the same data as Blog entry of yesterday, but also shows the

**relative signal strength**of the received signal.**UTC**in blocks of 1 hour.

Each rectangular black block indicates an hour, in which one or more

**spots**occurred and the calculated lowest possible power of that spot(s).

Vertically you find the lowest possible power, which is a good indication of the signal strength.

The

**lowest possible power**is calculated from the power of the sending station and the SNR of the receiving station. The higher the

**SNR**, the better the propagation and the lower the lowest possible power.

The

**lower**the**lowest possible power**, the**better**the**propagation**.Please notice, that

**not**all patterns in this propagation diagram,

can be easily recognized and can be easily explained. hi.

Propagation diagram. K5MQ WSPR on 40 m with 100 mW. |

**Propagation to WB5WPA over 500 km**

Dave 's signal was received by

**WB5WPA**over a distance of 500 km at 13 utc on the 24

^{th}with a calculated lowest possible power of 1 milliwatt.

From 13 utc on the signal becomes weaker. At 18 utc the signal is 10 dB weaker.

From18 utc to 1 utc on the next day, the process is reversed.

At 1 utc the signal has the same signal strength as at 12 utc of the previous day.

For the distance of 500 km we can see, that when the signal is reflected

in the ionosphere, the propagation is

in the ionosphere, the propagation is

**immediately**at it's best.
From that moment, the signal will be weaker, until the process is reversed.

**Propagation to N8SDR over 1100 km**

On the 24

^{th}we see the same pattern in the propagation, but this time throughout the night, between 3 utc and 10 utc. At 3 utc the signal suddenly appears and is immediately very strong . Than

**rapidly**becomes weaker (16 dB) and than

**gradually**becomes stronger again, to reach the highest value at 10 utc.

**Electrical field strength**

Dave noticed that

**K9AN**at a distance of 1003 km copied his

**100 mW**throughout the daylight hours, many times. And that he must have a

**great receiver**there.

To compare the signals of the different stations I made an analysis of the received signals by the Electrical field strength in micro Volt per meter.

The analysis below shows that

**K9AN**,

**N8SDR**and

**KE7TYT**received Dave's signal with the same field strength. hi. The difference between each of the columns is

**5 dB**.

A calculated

**lowest possible power**of 1 milliwatt means that a signal of 1 mW,

could be received with a SNR of

**-29 dB**.