The uBlox GPS-modules are capable of providing various reference clock signals through the TIMEPULSE pin. By default, this pin outputs a 1 pulse-per-second (PPS) signal. For an upcoming project, a GPS disciplined oscillator (GPSDO), this output had to be adjusted to 100 kHz. Instead of using the manufactuer’s software, u-center, this task is supposed to […]
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Search Results for: ms rim
JFET-based infinite impedance detector for AM-demodulation
The so-called “infinite impedance detector” is a circuit that was commonly used in the old days of vacuum tubes. Since vacuum tubes can be somewhat considered to be heated JFETs, it is evident that such a circuit can also be built using a more modern, silicon-based approach. This article covers my first experiments with a […]
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SITOR-B / NAVTEX Test Signal Generation
This article shows how to generate valid NAVTEX message bitstream using an Arduino. The Arduino implements proper CCIR476 character encoding, SITOR-B forward error correction, synchronization and phasing signals. An entry-level function generator is then used as a FSK modulator on 518 kHz where it can be received by a NAVTEX receiver. UPDATE: There also is […]
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Hacking a Strobe Light Controller
Not too long ago I bought some white strobe lights with a strobe controller of Amazon. This exact controller is spread all over Amazon and eBay but only provides strobe patterns that I didn’t particularly like. So it’s time for a hack. The strobe lights I purchased were white in color but they have the […]
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ILS Localizer / Glide Slope Test Signal Generation
In a previous video I have shown how to generate test signals for a VOR radio navigation system for aircraft.. This article will take a look at another radionavigation system, the Instrument Landing system or “ILS” for short. The ILS is used by aircraft around the world every single day. It is designed to guide […]
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Video Distribution Amplifier | 10 MHz Reference Distribution
Three Sigma VDA-100 Video Distribution Amplifiers (DA) have been sitting on my shelf for a while. The DAs have been waiting to be repurposed for something useful. When Jackson Labs sent me a custom variant of the FireFly-IIA GPS-Locked double ovenized 10 MHZ reference oscillator, I decided to repurpose one of the VDA-100 as a […]
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Tektronix RSA 306 | GPS Receiver and Clock Reference
The Tektronix RSA 306 is a great low-cost USB 3.0 spectrum analyzer for up to 6 GHz in an ultra low-profile format. If paired with the RSA Map function of SignalVu-PC and a GPS receiver, it becomes an extremely powerful tool for interference hunting and signal strength mapping. This article shows a possible way to […]
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DipTrace Export Settings for Dirty PCB
Dirty PCB offers – as the name implies – dirt cheap PCB manufacturing. The trick is a very low profile and a straight-forward system that needs minimum administration. This article is going to show how to set-up DipTrace to export a PCB layout correctly for Dirty PCB. DirtyPCBs.com offers super cheap PCBs for up to […]
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850 MHz Scanner Preamplifier / Filter Project
This article shows how to use off-the-shelf parts to improve the performance of a radio scanner in the 800 – 900 MHz band. Furthermore, it shows how to expand radio coverage by using two different receive antennas at the same time. For some reason, my new BCD996XT scanner wasn’t working as expected on the statewide […]
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Measuring filter response using a noise source
If you own a spectrum analyzer with tracking generator or, even better, a good vector network analyzer, measuring the frequency response of a filter is fairly easy. But there is one old approach using a noise source that can turn any oscilloscope with a FFT spectrum view into a useful tool for determining the frequency […]
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