Most modern transceivers have a built in interface. These interfaces work well in digital modes, but seem to lack support in analog voice modes. A case in point is the Yaesu transceivers that only permit the use of their internal interface when the transmitters are set to Digital Mode . Commercial external interfaces cost 100 Euro or more, depending on the additional futures.
Click here to download the full size of the above Circuit.
Due to the fact that most ham operators are on a limited budget, a homebrew approach is attractive. After examining various ways to interface the transceiver, it was found that the most practical way was using an Optocoupler via a COM port. The gain of using an Optocoupler in this project is obvious. First of all, the total number of components is reduced, and the electric isolation between the transceiver and the computer is achieved. Last but not least, the total cost of the interface is less than 5 Euro -quite a difference compared to the prices of the commercial interfaces available. The voltage swing on these lines is -12v/-5v through +12v/+5v, so a Optocoupler can handle quite nicely the negotiation between the rig and the computer. The interface is needed so the computer can send a request to the transmitter to transmit or receive. The most practical method is via a serial COM port using the RTS or DTR lines. Through these lines the PTT (Push to Talk) on the transmitter is activated. The analog audio is passed from the sound card directly to the audio in of the transceiver by simple cable connection. The circuit described below was made to connect the computer to the transmitter. It was designed as simple as possible to keep the number of components as low as possible. As soon as the program activates the RTS line (or the DTR) the negative voltage of the line turns to positive. This makes the Led D1 as well as the...
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.....
characters left: