Because of this audio mixer, I can compare the various receivers just by twiddling the gain controls. No switching required. Makes A/B comparisons a snap. (They are all driven by the same antenna). All of this used to be easy I just used a different speaker on each radio. However, once the receiver count soared up through 6 or 7, this solution started to lose its luster. Not only the
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cost, but also the space, consumed by all these speakers seemed to be getting out of whack. So another solution began to seem attractive. I put up with various frustrating switching arrangements for years before I got around to doing anything about it. This desire to listen to multiple rigs at once led me to develop a 20 input audio mixer. I run the audio from each receiver to the mixer, which then drives one speaker typically a Collins 312B-3. This allows me to listen to whatever radios I want without worrying about any switching. I still have several speakers to choose from, but whichever one I use is driven by the mixer and, therefore, all the receivers. Some of the mixer`s inputs are 8 ohms and directly accept amplified outputs that would normally be connected to speakers. Other inputs are 600 ohms and accept line level signals. Some receivers, like the R390A, have only a 600 ohm line level output. Others such as the Collins S line - have both types of outputs. I use whichever outputs exhibit less distortion. The design has been very successful. The mixer provides adequate output power (up to a couple of watts) with very low noise, and is nearly bullet proof with respect to RFI. The noise delivered to the speaker when all the radios are connected but turned off is only about 6 microwatts, which is just barely audible when I put my ear directly on the speaker grill and the room is quiet. I tried to keep leads very short...
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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