As the number of stations increased and the power levels also increased; receiver performance had to improve. The pentagrid converter, such as the 6BE6 tube (British EK90 valve), was introduced which was optimized for mixer performance. This included the isolation of local oscillator and input signal as well as allowing the first grid and cathode
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to work in an oscillator configuration. These tubes allowed a closer approximation to the multiplication of the two sine waves which produced fewer spurious mixing products. The British used a 7 grid tube with similar multiplication properties in FM broadcast receiver demodulators. They picked signals off the primary and secondary of the last IF double tuned transformer (which were 90 degrees out of phase) and multiplied them. The simplest modification seemed to be to use antiparallel diodes across the signal path to clip positive and negative peaks outside the +/- 0. 6 volt range (for two silicon diodes). I put the limiter at point A in the schematic. The limiter includes a 10k resistor between tank circuit A1 and the 470k resistor with the antiparallel diodes connected between ground and the connection point between the 10k and 470k resistors. I put a switch in the circuit to switch the diodes in and out of the circuit to compare the effect with and without the limiter. WMUC (88. 1 MHz) broadcasts with 10 watts of power and when the Pilot 100 is set to stereo, usually a grumbling splatter sound can be heard during silent passages which seems to be from interference from nearby stations, like NPR on 88. 5 MHz and probably other stations. Sometimes when WMUC is off the air I can hear a lot of noise at 88. 1 MHz which sounds like other stations bleeding over into that frequency, as well as another distant station on 88. 1...
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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