## Getting Started with Propagation Prediction

To generate a propagation forecast for a QSO between your QTH and a DX location,

select the

**Parameters**tab in PropView's Main windowin the

**Conditions**panelset the forecast

**Date**(this textbox will aready be set to the current date)type the current solar flux into the

**SFI**textbox; if you are running SpotCollector, the textbox will already contain the solar flux from the most recent WWV spotleave the

**Avail %**textbox set to 10

in the

**Transmitter**paneltype your QTH's latitude and longitude into the

**Latitude**and**Longitude**textboxes (e.g. 42 22' N and 98 45' W); if you are running DXView, these textboxes will already contain your QTH's locationleave the

**TakeOff**textbox set to 3type your transmitter power (in watts) into the

**Power**textboxselect either a

**Short**or**Long**path forecast; if you're just getting started with HF propagation, choose**Short path**-- the most direct route between your QTH and the DX QTH.

in the

**Receiver**paneltype the DX location's latitude and longitude into the

**Latitude**and**Longitude**textboxes (e.g. 40 15' S and 150 12' E); if you are running DXView, these textboxes will already contain the selected location's latitude and longitudeselect the

**Man-made noise level**like to be experienced by the DX station; for an optimistic forecast, choose**Remote**

click the

**Predict**button; PropView will compute a forecast, and produce a graphical display on the Main window's**Prediction**tab

### Interpreting a PropView forecast graph

After generating a prediction for propagation between two locations, check the **Prediction** tab's **Show Critical Frequencies** box and uncheck its **Show Open Bands** box.

PropView's forecasts are depicted on a graph of frequency (vertical access) vs. UTC time (horizontal axis):

The **black** curve represents the lowest useable frequency (**LUF**) as a function of time. Any frequency lower than the black curve will not support communications due to *absorption*.

The **blue**, **green**, and **red curves** provide a statistical range for the maximum useable frequency (**MUF**) as a function of time. The actual MUF will be at or above the blue curve with 90% confidence, at or above the green curve with 50% confidence, and at or above the red curve with 10% confidence. Any frequency above the actual MUF will not support communications, due to insufficient *reflection*.

At any specified time, you can identify which frequencies will likely support communication between your QTH and the DX location: they are bounded on the low-end by the black curve, and on the high-end by the statistical range between the blue and red curves. You can use the green curve as a kind of *expected MUF* curve; if you're an optimist, use the red curve for this purpose.

To make it easier to see what ham bands are open when, uncheck the **Show Critical Frequencies** box and check the **Show Open Bands** box:

PropView will display horizontal lines representing ham bands lying between the LUF and statistical MUF; the thickness of these horizontal lines conveys the likelihood of an opening: the thickest lines indicates openings based on the 90% confidence MUF (the blue curve), and the thinnest lines indicate openings based on the 10% confidence MUF (the red curve).

If you now check the **Show Critical Frequencies **box, the relationship between the horizontal lines and the critical frequency curves should be apparent:

Below the forecast graph's labeled time axis, two multicolored horizontal bars labelled **Xmitter** and **Rcvr** show daytime (yellow), twilight (gray), and nightime (black) conditions at your QTH and the DX location respectively. For the *low bands* -- 160m, 80m, 60m, and 40m -- twilight or dark conditions at both your QTH and the DX location are generally required: