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Equipment / Re: What's all this regenerative loop stuff?
« on: July 16, 2018, 1344 UTC »
A few comments about how the loop Q is controlled...
https://imgur.com/a/3eDNM2y
The above image is a cap of the main form of the app which controls the loop and rotator. This app has a number of tab pages to organize common tasks, and the RNA tab page is currently displayed below a collapsible pane. This pane can be collapsed to display the current loop resonant frequency and rotator bearing only, or can be expanded to expose some controls to directly manipulate the resonant frequency and loop Q. The control with the black background is the Q control and its functionality somewhat resembles a scroll bar. Clicking anywhere within the bar will send a value ( 0 to 255 ) to adjust the loop Q. This control will also respond to mouse wheel events. At any level, the current value is displayed in the text box to the right of the Q control. The vertical yellow bar represents the value above which there is actually a regenerative state in the loop.
The bottom part of the screen displays the current RNA database in a ListView control. This is an owner drawn control, and colors are used to add extra info to enhance the DXperience. In this scenario, domestic NDBs are rendered with a white background, Canadians with a red BG, and Foreign with a green BG. The selected item is rendered with a blue BG. Double clicking on any item in the database will tune the loop to that frequency, and spin the rotator to the proper bearing. Note that in the info panel that the bearing for the currently selected NDB is ~270 degrees relative to Chicago, whereas the rotator has been spun to 88 degrees. This app can use "Smart Rotation" and employs the fact that the loop response pattern is a symetrical Figure 8 pattern. This minimizes the amount of work (and rotation delay) required to get to the assumed proper azimuth.
https://imgur.com/a/3eDNM2y
The above image is a cap of the main form of the app which controls the loop and rotator. This app has a number of tab pages to organize common tasks, and the RNA tab page is currently displayed below a collapsible pane. This pane can be collapsed to display the current loop resonant frequency and rotator bearing only, or can be expanded to expose some controls to directly manipulate the resonant frequency and loop Q. The control with the black background is the Q control and its functionality somewhat resembles a scroll bar. Clicking anywhere within the bar will send a value ( 0 to 255 ) to adjust the loop Q. This control will also respond to mouse wheel events. At any level, the current value is displayed in the text box to the right of the Q control. The vertical yellow bar represents the value above which there is actually a regenerative state in the loop.
The bottom part of the screen displays the current RNA database in a ListView control. This is an owner drawn control, and colors are used to add extra info to enhance the DXperience. In this scenario, domestic NDBs are rendered with a white background, Canadians with a red BG, and Foreign with a green BG. The selected item is rendered with a blue BG. Double clicking on any item in the database will tune the loop to that frequency, and spin the rotator to the proper bearing. Note that in the info panel that the bearing for the currently selected NDB is ~270 degrees relative to Chicago, whereas the rotator has been spun to 88 degrees. This app can use "Smart Rotation" and employs the fact that the loop response pattern is a symetrical Figure 8 pattern. This minimizes the amount of work (and rotation delay) required to get to the assumed proper azimuth.