Circuit-Configuration Manager

Access the Circuit-Configuration Manager by clicking the "Circuits" button on the Master-Control Palette.

What is the Circuit-Configuration Manager

A "circuit", or communications circuit, is a grouping of all the sets of information required to create a HF propagation prediction. This includes transmitter and receiver locations, system parameters, receiver system parameters, month, ionospheric and solar variables, transmit (xmtr) antennas and a frequency set. The Circuit-Configuration Manager is the primary user interface for setting and maintaining “input parameter groups”.

The Circuit-Configuration Manager controls part of a powerful database. The database consists of a group of "tables". Each of these tables can have many "records". Each record holds related information or data and is called an “input parameter group”.

The Circuit-Configuration Manager is organized with a "page", or tab, control. Information on each page of the manager is stored in an “input parameter group” specific to that particular page. You don't actually need to know anything about all this - but the knowledge should be helpful in understanding that more than one circuit configuration can be ready to use. In other words, with “input parameter groups” you have quick access to many different circuit configurations, not just one. Sure you could change each input parameter item for each circuit, but that's the slow way; doing so will also change each "prediction batch" that uses the “input parameter group”.

Several pre-configured “input parameter groups” are provided. You can change any item in the pre-configured “input parameter groups” as you wish. However as you can create new “input parameter groups” it seems best to do so and not make random changes to existing groups.

The Circuit-configuration Manager is one way to change or select different “input parameter groups”. There are other “managers” that provide a grid-like view of several “input parameter groups” all at the same time – this makes it easier to compare and select from available parameter groups. Examples of other managers are the System-Parameters Manager and the Receive-System Manager. Additionally there are “browsers” - like the Frequency-Set Browser and the Transmit-Antenna Browser. The difference between a “manager” and a “browser” is with a manager you can edit existing “input parameter groups”; edit or change specific items within an “input parameter group” and “select” an “input parameter group” for use. With a “browser” you can “select” an “input parameter group” for use but not create or edit the “input parameter groups”.

The Circuit-configuration Manager and any of the Browsers and other Managers can be open and visible at once. However if you “edit” any item in a manager window the change is not immediately shown in the other window because you are still in "edit mode" - as soon as you begin an Analyze the changes are "first" saved and the corresponding windows will show the change. To explicitly save changes you can use the "navigator check button”. To abandon changes to an “input parameter group” click the "x" button to cancel edits.

The Circuit-Configuration Manager may be closed when not needed - but while creating predictions and prediction sets some parts of WinCAP Wizard operate faster with the Circuit-Configuration Manager left open. The reason is this keeps all the needed “tables” open so there is no need to open them later. We attempt to conserve your computer system resources and not keep unused tools active.

System

The system page holds parameters that configure the way the VOACAP prediction engine calculates the circuit. The button labeled "Manager" provides quick access to the System-Parameters Manager, a grid like display and a better way to compare previously created system-parameter groups - and select between them. Note - parameters on this page do not apply "directly" to prediction batch type predictions - although each circuit in a prediction batch can use one of these same groups, they are selected using the Prediction-Batch Manager.

Please refer to the labeled screen capture below for reference numbers in the following description.

#1 The area just below the window title bar provides a brief message to help understand what the information on a particular page is used for.

#2 These are the page control buttons. Click a specific button to access that “input parameter group”. In the image above, the "System" button is down. This is the default page when the Circuit-Configuration Manager is first opened.

#3 In the upper left of most pages is a Group Name". The "Group Name" is user defined; you decide what it should be. The group name should be helpful to more easily identify each set of parameters and also the matching group in the associated browser or manager. A button just below the group name, if one exists for that page, accesses the associated browser or manager.

Also shown in area #3 are three "check box" controls. These are the "Reverse Circuit" and "Long-Great-Circle" path and "IonCAP Absorption" calculations settings.

Reverse Circuit

The "Reverse Circuit" check box control is used to reverse transmit and receive end of the calculated circuit. This option should surely be used for beacon type predictions. When checked, the second page of the Circuit-Configuration Manager gets a different name, "Receiver" and additional options. Also, the "Receive System" page disappears, as its controls are then on the receiver tab/page. This control is the reason the "system" parameters page is presented first. Note - however, the "station" table and "receive system" table are separate - as they do not hold related information - they represent opposite ends of a circuit.

When you change from "forward" to "reverse" circuit the xmtr antennas configured also switch to the "other" end. In other words the antennas specified the transmit end of the circuit are always used for the transmitting station. Your "station" groups in Station-Parameters Manager have the special groups of "receive" parameters - "Man-Made Noise", "R Ant Name", "Gain" and "Az" that are used for reverse circuits and "your station".

In contrast, coverage prediction sets "can never be reversed" and so ignore the reverse circuit setting.

Likely the easiest way to view the antennas that were used for point-to-point circuits is using the "Results Inspector". The antennas are on the "header" and easily comparable.

Long Great Circle Path

The "Long Great Circle" check box control permits the user to force VOACAP prediction to use the longer of the two great circle paths for predictions. This is also known in amateur radio as simple long path or the "wrong way around". However the term "long path", in VOACAP, means any path greater than 10,000km and is calculated differently.

IonCAP Absorption

Use "IonCAP absorption" calculations. If unchecked the standard VOACAP absorption calculations are used. This setting primarily affects 40M and below. There can be a significant difference between prediction results created using the VOACAP and IonCAP absorption calculation. To change this setting the "Simplify Circuit Parameters" in Miscellaneous Defaults must be unchecked.

#4 This area of the system parameters page is used to select your desired transmit "mode" and the "quality" you wish to achieve. Together these parameters calculate a VOACAP input parameter called "required SNR". The required SNR parameter has always be very confusing, especially for new users.

The values used for mode and desired quality is user adjustable. For more information, and a discussion of required SNR, see the Signal Quality Selections topic.

#5 This area holds a "navigator control". The navigator control is used to move through and select the records - groups - held in a "table". It also provides buttons for adding, deleting and editing the records. The navigator is visible for all Circuit-Configuration Manager pages except "Month". In fact, the month page is an exception too much of this discussion.

When you make changes and you are satisfied with your changes, click the "navigator" button with the “check mark” indication to save the information. Clicking the "navigator" button with the “x” indicator will cancel any changes since the last save. When a prediction is started, any changed but not saved information is automatically saved. It is however a good practice - for you - to save changes.

#6 Near the bottom of the Circuit-Configuration Manager is the status line. The status line provides additional information for the display area, or control, under the mouse cursor. This information is often very useful while configuring a circuit.

The remainder of the input parameter fields on the system page are disabled, grayed, by default. They can be enabled using the Miscellaneous Defaults settings item named "Simplify Circuit Parameters". They can be used for special purpose type predictions. You can skip down to the next section. If you are setting up a "reversed circuit" the next Circuit-Configuration Manager page will be "Receiver", otherwise it will be "Station".

Minimum Angle

The Minimum take-off angle of the main lobe of the transmit antenna in degrees. The value is normally very small unless antenna performance is expected to be so poor at low angles that these angles should not be used in the estimation of upper useful frequencies, or if the horizon is so obstructed that low take-off and reception angles appear unlikely. Default is 3.0 degrees. Range [0 to 40 degrees], where 0 implies 3.0 degrees. Note - Use 3.0 degrees or higher for the Isotrope type antenna - If using an Isotrope type antenna we do not want 0 dBi gain below 3 degrees. This could be 10 to 20 dB greater than any practical antenna could develop at those low angles. The skywave pattern of an antenna over real earth has no gain at 0 degrees elevation. VOACAP uses values at 0 degrees, that range from -20 to -99 dBi except for the Isotrope antenna which has 0 dBi.

Required Reliability

The Required Reliability is an estimate of the percent of days within the month that the signal quality will be acceptable. It is expressed as a percentage (%). Range [10-90], default = 90%. It is best to leave this value at the default of 90%. The "required reliability" affects the calculation of the output parameter "SNRxx". Do not confuse this "required reliability" input parameter with the prediction "output" parameter "reliability".

Multipath Tolerance

The Multipath Power Tolerance (in decibels). The maximum difference in delayed signal power between sky-wave modes to permit satisfactory system performance in the presence of multiple signals. If zero, multipath is not considered. This only affects the output parameter MPATH - which is the estimate that two or more sky-wave modes will exist within the specified power tolerance and outside the time delay tolerance. Combines with Multipath Delay below. Range [0 to 40 dB], default = 10 dB.

Multipath Delay

The Multipath Time Delay (in milliseconds) The maximum difference in delay time between sky-wave propagation modes to permit satisfactory system performance in the presence of multiple signals. Combines with Multipath Tolerance above. Range [0 to 100 ms], default = 0.85 ms.

FProb

The FPROB variables allow the user to adjust the heights of the E, F1, F2, and Es (Sporadic E) ionospheric layers. The predicted critical frequencies are multiplied by these parameters to raise or lower each corresponding ionospheric layer. If the user-defined parameter is greater than 1.0, the critical frequency used by the program will be larger than the predicted critical frequency. If the user-defined parameter is less than 1.0, the critical frequency used by the program will be smaller than the predicted critical frequency. The user may remove the F1 & Es layers entirely by specifying the value 0.0.

A special note on the sporadic-E, foEs, multiplier is in order. In the book "Signal-to-Noise Predictions Using VOACAP", by George Lane, it is recommended that the multiplier for sporadic-E not be used. A multiplier of 0.0 is recommended, which effectively shuts off the sporadic-E model in the VOACAP prediction engine. The reason for shutting off the sporadic-E layer for circuit performance predictions is that it was found the model increased the composite-signal-power prediction by 2 to 4 dB at any distance and at any location in the world. When the foEs multiplier is set to 0, the signal-power calculation reverts to the values used by ITSA-1 (Lucas and Haydon 1966). The effects of the sporadic-E layer are included in the Transmission Loss Table so shutting off the model does not totally exclude consideration of sporadic-E layer effects.

WinCAP Wizard, by default, followed this suggestion for early versions. However comparing on air contacts, from field day for example, seems to show that disabling the sporadic-E model as described above results in far less realistic results. In other words WinCAP Wizard now defaults to the standard foEs multiplier of 1 and predictions appear much better.

Station - Circuit-Configuration Manager

The purpose of this page is likely obvious; it's the default group of "station" location information. This page is only displayed for "forward" type circuits; in other words not reversed - as is a correctly configured beacon circuit. A reversed circuit has a different group of parameters.

The "default station" - for a "forward" circuit is selected on the Circuit-Configuration Manager "Station" page; when the circuit is "reversed" the "Station" page is replaced with a "Receiver" page and the "Reversed-Circuit Receiver". In either case the "Station-Parameters Manager" always shows the current default station. See The Station Location topic.

#1 The "Group Name" is user defined; you decide what it should be. The group name should be helpful to more easily identify each set of parameters and also the matching group in the associated browser or manager.

A button just below the group name accesses the associated Station-Parameters Manager. The second button provides quick access to the DX Gazetteer. The DX Gazetteer provides a button, named "New Station", that can be used to quickly add "stations".

#2 This area holds the fields that define the "station", or station. Additionally, see the section Time Zone Picker.

City

Enter your Country and City information. The city is the most important for our purpose, as it appears on the charts and reports and helps identify the prediction. You could also enter you station call in place of the city.

Geographic Coordinates

Enter the geographic coordinates in decimal degrees and indicate if the location is North or South, of the equator and East or West of the prime meridian. If you do not know your coordinates you can look in the DX Gazetteer for a location near you. The DX Gazetteer provides a button, named "New Station", that can be used to quickly add "stations". If your station is in Canada or the USA and you have the call signs tables you can access the appropriate Calls Manager and search for your call then click the “New Station” button.

Time Zone

Click the “Time Zone” button to display the Time Zone Picker. Use the drop down list to select the time zone for the location you entered above. Click the OK button. This time zone is used on the charts to provide the correct “local” time on the upper axis.

#3 The "Manager" button provides convenient access to the Station-Parameters Manager and the DX Gazetteer button convenient access to the DX Gazetteer.

Finally, if you are satisfied with your changes, click the "navigator" button with the “check mark” indication to save the information. Clicking the "navigator" button with the “x” indicator will cancel any changes since the last save.

Receive System

 The Receive System page holds another, rather simple, group of parameters. This page is only displayed for "forward" type circuits; in other words not reversed - as is a correctly configured beacon circuit. A reversed circuit has a different group of parameters.

#1 The "Manager" button provides quick and convenient access to the Receive-System Manager.

#2 The receive-end-of-the circuit noise level. This is not the user station, but the other end of the circuit. Select one of the four preset values to indicate the noise at the receive site. This selection can have a significant effect on the predictions.

Receive Noise

The "Receive Noise" indicates the expected man-made noise level at the receiver in dBW (decibels below 1W) in a 1 Hz bandwidth at 3 MHz. Receive noise relates to the receiving location area as follows:

Industrial -125 dBW

Residential -136 dBW

Rural -148 dBW

Remote -164 dBW

#3 The receive-end-of-the circuit antenna system.

Select Antenna

Click the “Select Antenna” button to choose an antenna other than an Isotrope. The default antenna is a good starting point and you are not required to change this now. The related “Gain” value is dB gain over an Isotrope. The “Bearing” value can be set at -1 to cause the antenna to be “pointed” toward the transmitter, or other station. The “Antenna Selector” is similar to the “Antenna Browser”.

Finally, if you are satisfied with your changes, click the "navigator" button with the “check mark” indication to save the information. Clicking the "navigator" button with the “x” indicator will cancel any changes since the last save.

Month

The month page holds a number of options related to the month for which you wish to create predictions. No changes are required from the default values. These options are intended for those interested in experimenting, or creating special purpose predictions.

#1 The coefficients parameter is disabled, grayed, by default. It can be enabled using the Miscellaneous Defaults settings item named "Simplify Circuit Parameters". They can be used for special purpose type predictions.

Coefficients

The first option selects the ionospheric “Coefficients” that will be used for creating predictions. The default is “CCIR”. The URSI 88 (Australian) coefficients are a linear fit between SSN LOW (1975-1976) and HIGH (1978-1979). They were developed by Australia and accepted by URSI in 1988. Data was also added over the oceans, a deficiency with CCIR. The CCIR coefficients cannot be interpolated by day of the month. It is probably best to use the CCIR as "the URSI 1988 (Australian) coefficients could introduce errors in VOACAP since the foF2 data is not consistent with the epoch for which other critical parameters were measured".

Use current month

#2 The second option is “Use current month”. When checked, the host computer system date will be used for predictions. When unchecked, you should select the desired month in the "Predict Month" area. By un-checking this option, you can easily create predictions for the four seasons – marked by January, April, July and October, conveniently located across the top row of months. Un-checking this item also enables the field labeled "year".

The "year" in VOACAP is only used as a label. However in WinCAP Wizard the year is used to select the correct set of "stored Smoothed-Sunspot Numbers", described below.

#3 The daily coefficients parameter is disabled, grayed, by default. It can be enabled using the Miscellaneous Defaults settings item named "Simplify Circuit Parameters". They can be used for special purpose type predictions.

Daily Coefficients

Option number three is “Daily Coefficients”. Typically this should not be used. It is best to use only the month and no day. This allows you to specify day-of-the month and have Jan 31 results be very similar to Feb 01, etc. When checked, and “Use system date” is unchecked, enter a "day" and "year" value. With this option the VOACAP prediction engine will automatically use URSI coefficients.

Use stored Smoothed-Sunspot Number

#4 Option number four is “Use stored Smoothed Sunspot Number”. When checked the smoothed-sunspot number, from the "SSN" page of the Circuit-Configuration Manager, matching the selected date is used. When unchecked, enter a Solar Flux or SSN. The default smoothed sunspot numbers (SSNs) are available on the SSN page; see below.

These last two controls, Solar Flux and SSN, in effect provide a calculator. For example when you enter one type value the other type is calculated and displayed.

In either case it is best to use a "smoothed" type value and not the solar flux right from WWV. IonCAP, and therefore VOACAP, was developed based on a correlation between SSN and monthly median ionospheric parameters. Using daily values tends to cause significant errors in predictions. However, WinCAP Wizard provides a "best fit" to equivalent SSN when the current solar flux is used.

SSN

The smoothed-sunspot number page provides a group of predicted numbers - one for each month.

#1 Update - When enabled you can click and automatically update the stored predicted smoothed-sunspot numbers. When WinCAP Wizard is installed in the same folder with GeoAlert-Extreme Wizard, and GEW is run regularly, updates of "predicted" smoothed-sunspot number data become available. When such updated data is available this button becomes "enabled". New data updates are typically available the second Tuesday of each month.

#2 This area holds smoothed-sunspot number values for and entire year. These values are user editable and more year/month combinations may be added. Be very careful about deleting year groups. It may be a good idea to update the provided SSNs every 6 months or so. The best source of current SSN data is "Space Environment Center". http://www.sec.noaa.gov

The easiest way to get this data from SEC is using the GeoAlert-Extreme Wizard (free bonus with WinCAP Wizard and download-able from http://www.taborsoft.com/ ). GeoAlert-Extreme Wizard must be installed in same folder as WinCAP Wizard. When GeoAlert-Extreme Wizard retrieves the monthly update, the "Update" button on the SSN page of the WinCAP Wizard Configuration Manager will become enabled.

For more information see the section titled "Smoothed Sunspot Number".

Xmtr Antennas

These are the antennas used for the transmit end of a circuit. The controls on this page function similar to those described above for the receive antenna.

#1 The "Group Name" is user defined; you decide what it should be. The group name should be helpful to more easily identify each transmit antennas group and also the matching group in the associated "Transmit-Antenna Browser".

#2 This area defines the first of up to four transmit antenna specifications.

Select

The Select button allows you to select any antenna from the antenna directory structure. See the Available Antenna Browser for more information. The selected antenna file name will appear to the right of this button.

Max

The "Max" is the maximum frequency for which this antenna will be used. Range [3-30] MHz.

Freq/Gain

For an Isotrope type antenna, the default, this is the gain in dBi. Alternatively, the design frequency, in MHz, is used here only for some Rec705 antenna types. A zero, will force the design frequency = operating frequency (if appropriate). A gain value entered for antenna types other than Isotrope will be ignored.

Bearing (Az)

The Bearing is the main beam azimuth of the antenna in degrees from North. The AZ range is 0-360 in the clockwise direction; for example East=90. To force the transmit antenna to point directly at the receive location enter -1.

Power (kW)

The transmit power in kilowatts delivered to each antenna should be specified. For example 0.1 is 100 watts. The available power range is 0.001 to 9999.99.

#3 This area provides for up to three more transmit antennas specifications. When the "max" frequency of an antenna is less than 30 MHz the "next" set of specifications becomes enabled.

For more information, see the sections titled Antennas and Available Antenna Browser. Additionally, please consult the VOACAP documentation.

Frequencies

The frequencies page allows entry of a group of frequencies to be considered during predictions.

#1 The "Group Name" is user defined; you decide what it should be. The group name should be helpful to more easily identify each set of frequencies and also the matching group in the associated Frequency-Set Browser.

#2 Enter one to nine frequencies. You should always specify at least one frequency. The first zero value indicates all desired frequencies have been entered.

See the Things to watch out for while operating Wizard section.