A plot showing the paths of the recently-tracked and currently-tracked satellites. The receiver`s location is the `bull`s eye` in the center while the top of the plot represents the North pole. The red line shows the `EFC` value - the setting of the electronic tuning adjustment which is an indication of how far the Z3801`s internal oscillator departs from GPS time and the tuning
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required to correct it. This page is intended to document only how I put my system together and a few other miscellaneous items. It should go without saying that there are probably better ways to do these things, that your mileage may vary, blah blah blah. Back in 2003 I bought a used HP Z3801A GPS receiver (often called a "Z-Box") with the intent of using it as a time/frequency reference. As with most projects, this one was ongoing, with incremental progress dependent on available time and current whim. Nevertheless, it didn`t take too long to get it up and running, following the "make it work, then make it look good. " mantra. A known-good frequency reference is handy for making sure that everything else is on frequency. At this location (Utah) reception of WWV on 10 MHz (the most convenient frequency for calibrating against) is very sporadic and it is often difficult to get a good zero beat owing to the constantly changing path and the usual presence of WWVH. Over the years the Z3801 has been invaluable for use as a frequency reference. With it, I have been able to assess the stability of OCXOs (Oven-Control Crystal Oscillators) and Rubidium references for use with microwave ( 10 and 24 GHz transverters ) as well as use its 10 MHz output as an external reference for a frequency synthesizer to generate reference markers for use in the ARRL Frequency Measurement Tests (FMT`s) - among many other things - and with accuracy...
This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of....
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is....
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to....
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This....
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the....
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound,....
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the....
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power....
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower.....
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