Yesterday was my first time out with the system actually working properly. Apparently my phone is “evil” some how. Samsung S23 Ultra.
I have my antennas configured for 2m foxhunting, but I decided to start by hunting a weak FM BCB station at the top of the band, since they are of course on all the time. 77 miles later (!!!) I ended up at the locked gate leading to the transmitter site. Not bad for “first light”. I doubt I could have gotten there faster if I had the address! This reminds me of my Wisconsin days with N0MKJ and the “foxcopter” (Continuously rotating 5 EL quad and storage scope)
One thing that bothered me is that when I enter the frequency it takes a while (minutes) to start plotting bearings. I’m not understanding why that is.
I did notice that while driving I was getting the green target signal a few miles north of my position, and the target kept moving. I assume this is because the TX was basically directly north of me for 90% of the drive. I could see that the bearings were not rotating yet as they do if you’re not driving directly at the TX, so I wasn’t misled.
One other thing that popped up for me is that the heat map was very undersized, and I’m not seeing how to adjust that, or if it’s adjustable.
Is there a tutorial that discusses the various settings?
As the area in which I’m using the Kraken is about 150km “high” and 60km “across” I’ve changed the grid size to 50km, number of grids per axis to 500 and the trace line length to 50km: This seems to enough to include area to encompass more distant transmitters (e.g. repeaters when checking calibration).
I’ve not noticed a long time to obtain bearings with a frequency change, but I did notice that changing the sample rate from 2.4MSPS to 1.024MSPS seemed to cause it to take a few seconds longer to do the noise/calibration functions.
A few interesting “gotchas” are:
In the SDR configuration, the gain setting (just below the frequency) is set to 20-ish dB which will result in very frequent “overload” indications in a typical urban area with normal 2 meter/70cm activity (e.g. repeaters). As the useful signal range between the weakest and strongest signal that this receive hardware can tolerate is about 60dB, one must be sure that the manual gain is set appropriately for your RF environment - and if you are getting closer to a strong transmitter, you may need to pull over and adjust it from time to time.
Setting to “Auto” gain didn’t appear to do anything useful as the “Overload” condition persisted on the status display: More experimentation is required.
Interestingly, setting to “Auto” gain causes a warning to pop up about the different receivers adjusting gain asynchronously from each other with the possibility of errors. In the case of gross overload, signals may be diluted and cause errors, anyway - but I do wonder why the gains of the receivers aren’t in lock-step with each other: Any conditions in which an array of 5 identical antennas do NOT get extremely similar signal levels would be very transient, indeed, so the “worst-case” level (in terms of high signal strength) should likely be appropriate to set the gain of them all. Also, while decreasing gain in the presence of a very strong signal should probably be done fairly quickly, increasing again would best be done comparatively slowly - as the manner of all AGC circuits you’ve ever seen.
The heatmap size can be adjusted in the app settings under “Total Grid Size”. Remember that if you increase the grid size, then the resolution decreases. If you want to maintain the same resolution, increase the number of grids per axis setting. But note that only fast devices can handle more grids.
Hmm I’m not sure why that could be. It could have been stuck in a calibration loop for a while. Calibration can sometimes rarely take a couple of minutes instead of a few seconds if the initial conditions are way off for some reason.
Ok, thanks! Now that my connection issues are sorted out, I am really getting into this bigtime, but it’s a bit like starting from scratch with a bit of un-learning thrown in.
I doubt I could have gotten there faster if I had the address! This reminds me of my Wisconsin days with N0MKJ and the “foxcopter” (Continuously rotating 5 EL quad and storage scope)