CT255 Thermometer Assembly Instructions

CT255 THERMOMETER ASSEMBLY INSTRUCTIONS

Although we know that you are anxious to complete the assembly of your binary thermometer kit, it is best to follow the numbered assembly steps when building. Try to avoid the urge to jump ahead installing components.

Since you may appreciate some warm-up soldering practice as well as a chance to put some landmarks on the PC board, we’ll first install some of the larger components. This will also help us to get acquainted with the up-down, left-right orientation of the circuit board. Remember that the majority of the components will be mounted on the component side of the circuit board and soldered on the solder side of the circuit board, the side that contains the printed circuit traces. Have a look at the component layout diagram to help with your assembly.

Use the boxes to check off your progress.

Check all received parts against the Parts list on page 15. The parts list describes the various markings that may be found on the kit parts. Carefully sort the parts into small piles, if helpful (an egg tray does nicely for this) to aid in finding the correct part at the required time.

Although not necessary, you may install IC sockets in the U1 and U2 position. Today's ICs have achieved remarkable performance levels and it is extremely unlikely that any of your chips will have problems, however, we know that some of our hobbyists insist on socketing all IC components. The addition of these will not “void” your warranty, but if a problem arises from a socketed component you will be required to pay the additional technician fee for labor in the repair of your kit, if necessary.

Now we will build the power supply portion of the circuit. We use a 7805 voltage regulation circuit to provide for a clean, trouble-free voltage source for the binary thermometer. It is critical that the power source be free of noise and any hum for proper operation of the kit.

1. Identify and install power connector J2 towards the rear of the printed circuit board. Gently slide the leads through the circuit board until the connector is flush to the printed circuit board, with the connection hole facing towards the outside of the kit, and solder all three connections. Use enough heat to flow the ground connection completely; this may take a little while depending on the wattage of your soldering pencil. Use caution when soldering the other two leads so that too much time or heat is not applied. It may cause the printed circuit trace to lift away from the circuit board.

2. Identify D10, the 1N4002 diode (black with white band). Install as shown in the parts placement diagram, noting the proper orientation of the polarity band (D10 is adjacent to the power input connector you just

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CT255 specifications

The Ramsey Electronics CT255 is a versatile and advanced communication tool designed for radio enthusiasts and professionals alike. As a 2-meter FM transceiver, it is known for its robust performance and extensive feature set, making it ideal for both casual users and serious operators.

One of the standout features of the CT255 is its compact design, allowing for easy integration into various environments such as home stations or portable setups. The unit is built with user-friendliness in mind, featuring an intuitive interface with a clear display and easily accessible controls. This ensures that users can quickly tune into their desired frequencies and modify settings without extensive technical knowledge.

The CT255 operates on a frequency range from 144 to 148 MHz, providing access to the popular 2-meter amateur radio band. This frequency capability is complemented by an impressive output power of up to 25 watts, ensuring robust communication over extended distances. It also includes a built-in automatic repeater shift, which simplifies contacts through repeaters, making it an excellent choice for those looking to enhance their communication range.

In terms of technology, the CT255 employs advanced digital signal processing (DSP), which significantly improves audio clarity and reduces background noise. This makes communication clearer, even in less-than-ideal conditions. Additionally, the transceiver features an array of scanning functions, including memory scan and priority scan, allowing users to monitor multiple channels effortlessly.

The CT255 comes equipped with multiple memory channels, enabling easy access to frequently used frequencies. This feature is particularly useful for users who participate in various nets or have multiple repeaters they commonly contact. Moreover, the unit supports CTCSS and DCS tones, which adds an extra layer of privacy and reduces interference from unwanted transmissions.

Safety and durability are also key characteristics of the CT255. The robust construction ensures it can withstand the rigors of regular use, making it suitable for field operations. It is designed with heat dissipation features to prevent overheating during prolonged use, ensuring reliability during critical communications.

In conclusion, the Ramsey Electronics CT255 is a well-rounded transceiver that brings together advanced technology, user-centric design, and excellent performance. Its range of features makes it an appealing choice for radio amateurs seeking a dependable and efficient communication solution. Whether for casual chatting or emergency communications, the CT255 stands out as a reliable tool that meets the demands of modern radio users.