For the impatient
At Youssef' Touil's request, and in order to comply with the MSIL license of SDRSharp that essentially restricts its redistribution, I have removed the files behind the links. The frequency manager is now part of the latest builds of SDRSharp, and saving of settings has been added. I will be developing scanner functionality for my own use and may release it here in a couple weeks.
This release adds two new collapsible panels, "Frequency Manager" and "Scanner", as well as a few internal changes.
The Frequency Manager allows you to store frequencies, as well the associated offset, mode, center frequency, bandwidth and a user provided name and groups. Groups, such as "Police", "Fire & EMS" and "2m Ham", allow you to display related entries together. Entries are stored in "%LOCALAPPDATA%/SDRSharp/frequencies.xml" in XML format. %LOCALAPPDATA% is a Windows enviroment variable that defines the location for local application data, and its location varies depending on the version of Windows used. For example, on Windows 7, it is typically found in "c:\users\username\AppData\Local".
The Scanner allows you to scan the selected spectrum for activity on any of the stored frequencies found within the selected spectrum. Its operation is controlled by two variables, the linger delay and signal level. The signal level defines the minimum signal level needed to trigger a channel change. The linger delay, which can be set to a value between 0 and 5000 milliseconds, defines how long a channel can be inactive before it is considered to be no longer transmitting. A higher value will prevent a scanner channel switch in mid sentence or mid conversation.
The program was also modified to remember a few settings, so that the next time it is started, it can resume where it last left off. The currently remembered settings are the current front end device, frequency, mode, center frequency, filter bandwidth, audio gain, FFT resolution, contrast of the waterfall display, zoom of the spectrum display,the window size and position, the position of the spectrum/waterfall splitter, the currently selected frequency manager group, the afore mentioed scanner settings and the collapsed/expanded state of each collapsible panel. Settings are stored in XML format in "%LOCALAPPDATA%\SDRSharp\SDRSharp.xml". Finally, the behavior of the collapsible panels was changed so that clicking any part of the title bar (rather than just the label text) toggles the panel.