im looking to hunt gps jammers in my area, just wondering what kind of measurements do i need to put for the antennas and also are the kraken sdr antennas that come with is it good to track down L1 bands 1575.42 MHz or do i need to find something else.
The kraken antennas and cables are not designed for over 1 GHz.
For GPS, you probably will need to create a custom array. At that frequency you really need to pay attention to precision, as even small errors in the array positioning, or length discrepencies between cables can have a big effect.
So probably an SMA PCB array would work ok.
did anybody on this forum already make the custom array, i would need some guide or help to make this work.
Here’s a source for PCB antennas, if that helps you get started:
https://www.pasternack.com/nsearch.aspx?Category=Antennas&Rfpsan99design=PCB&view_type=grid
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No need for PCB antennas, just trim some decent sma whips, at 1575.42 I’d cut to half-wave instead of 1/4. Not for tx, so exact antenna length is less important than matching cable lengths. The images show spacing for 1600MHz, put 8ishmm holes on a disk at those locations for your array and you’d be set. I do recommend you measure and print a jig for trimming the whips, if just to keep them even.
Before making an array of antennas for KRAKEN on the GPS frequency, you need to understand how well you can receive the signal from the jammer. This will allow you to understand whether or not you can use KRAKEN to find it. To do this, you can use any simple SDR receiver with a telescopic antenna. You also need to understand that the real GPS signal is very weak. And it’s not easy to see it on the waterfall of an SDR receiver. Watch the YOUTUBE video of what the GPS signal looks like at the waterfall. If you know how to distinguish the signal of a real GPS from the signal of a jammer on a waterfall of a simple SDR receiver, then you can start making an array, otherwise you will waste time and effort. At this stage, you can select the type of antenna capable of receiving the jammer’s signal. The next difficult task is to make five identical cables. I used a homemade AD8302 phase detector for this purpose. For this frequency, the cables must be short, as there will be strong signal attenuation. If you decide to make an array of antennas, see how it is done in this article “Creating an Antenna Array” KrakenSDR Multichannel Phase-Coherent Receiver for AoA Measurements | Elektor Magazine and more in this video https://www.youtube.com/watch?v=0EsflW9Rr9w