Replacing the front-end with a circuit that down-converts VHF signals in the 2m, 4m or 6m bands to HF signals that can be received in the RX`s `back-end` (which is essentially the Ensemble II RX). The parts provided in this kit permit the builder to select which of the major VHF bands to implement; all the parts for all the options are included in the kit.
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Band-specific parts are identified throughout the documentation; the builder makes his/her choice at build-time. The builder will find invaluable information at the website of Fred PE0FKO, especially the setup of the software and firmware, as documented in the excellent users manual from Bob G8VOI. This kit reuses a large percentage of the design of the Ensemble II RX (HF/LF) kit. Refer to that kit`s home page for a theory discussion on the radio. This kit reuses the following stages, basically untouched, from the Ensemble II RX: The main difference is in the RF and COntrol stage, which is based upon an earlier design for a VHF add-on board for the Softrock V9. 0 RX. The theory of the Software Designed Radio can be gleaned from the Ensemble II RX documentation. Here, we will concentrate on the differences (where the RF/Auto BPF functionality is replaced with the stage described in the following paragraphs. This discussion will use, as an example, a 144 MHZ signal that will be down-converted to an IF in the apporpriate HF frequency range for detection in the "standard SDR" stages. The incoming signal from the Antenna terminal (or, via a jumper wire from J1/P100 Pin 1), e. g. , 144MHz, is filtered, then pre-amplified by Q1 and fed to a double-balanced mixer, U7. U7 also receives a Local Oscillator signal via from the Si570`s (U3`s) LO Out. This local oscillator signal must be at a frequency (in our example, 115. 2 MHz)...
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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