A panadapter is a display that shows signal information over a range of frequencies. One type of display is an x-y plot with frequency along the x axis and signal amplitude along the y axis; this is often called a spectrum plot. Another type of display is the waterfall, also with frequency along the x axis, but with time along the y axis and colors associated to signal amplitude. The Elecraft P3 device presents both of these displays on a small screen, like this:
SkookumLogger extends the usefulness of the P3 panadapter integrated with the K3/K3S radio in several ways:
This is an example panadapter window:
The window is resizable, with constrained aspect ratio and heights between 270 and 1080. The example image is 960 x 540, illustrating what you are likely to see with decent readability on a non-retina display. The y-axis of the waterfall is about 150 seconds.
Known calls, from the appropriate Activity table, are identified by thin vertical lines at their frequencies, with the calls shown in staircase fashion in the waterfall area. The colors of the lines and calls are determined by their needed status. For example, in this case “9L1YXJ” (busted call — was 9LY1JM) is a needed QSO while F5IN has been worked before. The use of color cues for needed status is the reason that grayscale is more appropriate than “heat map” colors in the waterfall display.
The known calls lines are interrupted near the boundary between the spectrum plot and the waterfall to avoid obscuring additional graphics associated with the radio. This is an example of the radio information graphics:
The green line is located at the main receiver frequency. The translucent green box is the main receiver passband. A similar display is provided for the subreceiver when on, with magenta color. The red line is located at the transmit frequency.
The two inverted-U graphics are drawn by the P3 firmware at slightly incorrect frequencies; there is no way to turn them off.
The SkookumLogger Panadapter requires an Elecraft K3/K3S, an Elecraft P3 with P3SVGA option, and an Epiphan Systems AV.io HD video grabber.
Connect the P3SVGA video output to the AV.io input with the cable included with the AV.io. Connect the AV.io output to a USB3 computer input with the cable included with the AV.io. In the P3 SVGA menu, set SVGA res to 1920 x 1080 alt.
Start SkookumLogger. SkookumLogger will discover the AV.io device and explain how to allow access to the video:
This only needs to be done once.
You may find that the video image is not centered in the window. In that case, download the Webcam Settings application from the App Store and use it to adjust the Pan and Tilt settings (Advanced tab) for the AV.io HD Video device. This only needs to be done once.
You may want to fuss with the SVGA bias setting in the P3 SVGA menu, which seems to affect the dynamic range of the amplitude colors in the waterfall. Mine is set at 2.
You may want to adjust your needed color choices to obtain adequate contrast against the mostly-black background of the waterfall and the blue background of the spectrum plot. I use these settings:
If you care about using both Dark Mode and Light Mode in Mojave, use the Color Chooser to select items in the Developer Palette with name beginning with system:
Window ► Panadapter opens the SkookumLogger Panadapter window. The panadapter provides nearly-instant situation awareness at a glance. Locate the window near your Log window where you can inspect it without turning your head. The window is associated with Radio 1.
SkookumLogger reads the SPAN and CENTER settings from the P3, and uses them to compute the frequency of the left end of the frequency axis and the scale factor along the frequency axis in pixels per Hz. However, if the P3 reference oscillate calibration is off, the frequencies of blips will also be off. A quick way to deal with this is:
Click inside the Panadapter window to make the window active and to show the grab cursor:
The grab cursor is a vertical white line that spans the height of the window. The line follows your mouse and you move left and right within the window, updating the frequency display for the horizontal location of the grab cursor. If the frequency is near a known activity, the call is also drawn above the frequency.
Click to set the radio to the grab cursor frequency and make the Log window/Pounce entry active. If the “Fills QSO entry from nearby activity” option is on in Activities preferences and the grab cursor is near a known activity, the activity information is loaded into the Pounce entry fields. If instead the “Creates activity from QSO entry and clears entry” option is on and the Pounce QSO entry box is not empty, the click creates an activity. Use the first setting when your activity table is filled with many known signals. Use the second setting when you want to add unknown signals to your activity table.
Shift-click to set the radio to the grab cursor frequency and make the Log window/Run entry active. Use this to begin CQing on a new frequency that appears to be clear.
Use Radio 1 ► P3 Medium or Radio 1 ► P3 Wide to see many signals (AKA blips) on the current band.
This is an example with the P3 span at 20 kHz, centered near the middle of CWT activity. The waterfall plot was reset when the span changed so is mostly black. At this point I had worked about 70 QSOs, yet most of the known calls are red (needed multipliers), suggesting the band is far from “worked out.”
In the next example the span is 50 kHz, illustrating typical congestion in a popular contest when generating known calls from skimmers in New England states. Either one of these examples is useful when you are looking for unknown or needed blips.
Use Radio 1 ► P3 Narrow to see and quickly tune to callers near your run frequency but possibly outside your receive passband. Often you will see a needed buddy spot indicator for yourself. Skimmer spots have resolution of 100 Hz, truncated not rounded, and typically have accuracy worse than the resolution. Many callers don‘t bother to account for that, so you should adjust your receive passband to include your spot indicator line — usually somewhat below your transmit frequency.
The P3SGVA video freezes when the radio is transmitting. Any delay between end of transmitting and the return of video updating can be bothersome, especially when running at a decent rate and someone calls outside your passband. I found that turning off the P3TXMON option was necessary to minimize the delay.
For this example, the P3 span is 2 kHz. The main receiver bandwidth is 250 Hz wide. While preparing this screen grab, I switched to ANT2 for 15 seconds, causing dark bar, to provide a sense of the duration of the waterfall plot. I had been CQing on this frequency, watching the panadapter to detect callers outside green box bandwidth. KJ9C grabbed “my” frequency; N1LN and K9NR were CQing on each side of me. I had worked N1LN and needed K9NR. K5AX apparently tried to squeeze between KJ9C and K9NR but either gave up or suffered a bad spot.