The above circuit is recommended for use in SSTV applications with use of the sound card with a computer. This is the JVComm style of interface. This circuit may also be used for RTTY and PSK31 applications. Many users modify the above circuit to include 1:1 isolation transformers within the Speaker out and Line-in or microphone in lines.
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These isolation transformers are used to preclude ground loops within a system from introducing hum and interference on the transmitted signals. The following circuit is used in applications of WinRtty for receiving RTTY signals using the sound card. This circuit is also applicable to SSTV and PSK31 modes and works well in all three applications. This circuit may be implemented into the JVComm interface shown above as discussed in the JVComm interface text. Note that the sound board and receiver are transposed in the two circuits. The following circuit is used in applications of WinRtty for transmitting RTTY signals using the sound card. Notice this circuit does not have a PTT component and relies on VOX for transmit control. This circuit is also applicable to SSTV and PSK31 modes and works well in all three applications. This circuit may be implemented into the JVComm interface shown above as discussed in the JVComm interface text. Note that the sound board and transmitter are transposed in the two circuits. So you say I want FSK capability as well as Push-To-Talk (PTT). The following circuit is used with WinRtty to provide capability for FSK Rtty and a PTT circuit for the program. This circuit may be used in many applications and may be substituted for the circuit contained in the JVComm interface shown above. What goes in the RS-232 conversion box depends on your transmitters FSK input. Odds are, it can be exactly...
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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