Next we will install some of the output voltage divider resistor networks. The circuit board has been laid out to avoid confusion with these multiple rows, and we will try to avoid sounding too redundant when installing them, Remember to save those leads as we will be installing some jumper wires very soon. Pay particular attention when installing so as not to mount the resistors in the improper locations.

ˆ7. Install R36, R33, R29, R26, R21, R19, and R17, all 10K ohm (brown- black-orange).

ˆ8. Moving on to the next batch of resistors, install R38, R35, R32, R28, R25, R20, R18, R16, R13, and R14, all 20K ohm resistors (red-black- orange). Be sure to solder the ground plane connections of R14 and R38 completely as they will take a little extra time to flow the connection.

ˆ9. Install resistors R5-R12, 390 ohm (orange-white-brown).

ˆ10. Using a scrap component lead, form a jumper wire and install in the JMP1 holes. Jumpers act like electronic “bridges” that carry power or signals over active traces on the circuit trace side of the board.

ˆ11. In the same manner, form and install jumper wires JMP2,JMP3 and JMP4.

That’s getting the hang of it! Believe it or not, you are already halfway through the assembly of your kit. Recheck your solder connections, touch up any less than perfect connections that you see. Watch out for any solder bridges on the IC pins or at the jumper wire connections.

Let’s get to work on that scaling amplifier. We’ll start at the IC and work our way out in both directions to avoid crowding.

ˆ12. Install U1, the LMC660 Quad Op-Amp 14 pin IC (marked 324). Make sure to align the notch or dot associated with pin one with the notch shown in the parts layout diagram. It may be helpful to gently “rock” the IC on its side on a hard flat surface before installing to align the rows of pins so that they slide in easily. Don’t be afraid to use enough solder and heat for a good solder connection, and be extra careful not to “bridge” any solder connections together

ˆ13. Identify and install D9, the 1N4148 small signal diode (glass case with black band). Remember that diodes are polarized, so face the banded end as shown in the parts placement diagram. This is one of the more fragile parts you’ll install so use caution so you don’t flex the leads of the device at the junction of the lead wire and the glass case. Solder in place and remove any excess lead.

ˆ14. Install R24, 1 Meg ohm (brown-black-green).

ˆ15. Install R3, 10K ohm (brown-black-orange).

CT255 • 19

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Ramsey Electronics CT255 manual
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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.
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