Ramsey Electronics DN1 specification

1. Identify and install DPDT switch S2. Be sure to push the switches flat to the circuit board. Solder all six connections.

2. Install the other DPDT toggle power switch S3. Once again, be sure to push the component flush to the circuit board before soldering.

We’ll start our “learn-as-you build” instructions with the power supply section of the circuit.

3. Install the 2.5 mm power connector in the J3 position.

4. Install D6, a 1N4002 type diode. Notice that one end of this component is marked with a band. Diodes are “polarized”, that is, like a battery, they have a positive (+) and negative (-) side. Be

sure to follow the parts diagram carefully and orient the banded end as shown. Note also that this component will

“stand up” in place. Form the component leads as shown before installing the part.

5. In the same manner, install diode D5, 1N4002 type. Be sure to orient it correctly! See the parts diagram for correct placement.

Diodes D5 and D6 act as circuit “protection”. If the power is hooked up incorrectly D6 acts as an “open circuit” to prevent damage to the voltage regulator and the charger IC. Diode D5 prevents the battery pack under charge from powering the unit if the input power is accidentally removed.

6. Install C5, 10 uF electrolytic capacitor. Electrolytic capacitors are polarized with a (+) and a (-) lead and must be installed in the correct orientation. Ordinarily, only the negative side is marked on the capacitor body with a dark band and the (-) sign clearly shown, while PC boards will usually show the (+) hole location. Use care to ensure proper polarity. See the parts diagram for proper placement.

7. Install C6, 10 uF electrolytic capacitor. Watch the orientation! See the parts diagram for proper placement.

8. Identify VR1, the 78L05 voltage regulator (marked 7805). This device produces a stable 5 volt reference for the circuit. Notice that this component has a “flat” side with the writing imprinted on it. Be sure to place the part as shown in the parts diagram.

9. Install C2, 10 uF electrolytic.Observe the correct polarity! If installed incorrectly, this component can heat up and even explode!

That wasn’t so bad, now was it! You have just completed the power section of your DN1. Take a moment now to recheck your solder connections and touch up any less than perfect connections. Have a second look at the component polarities in this section as the majority of these components have a (+) and (-) orientation.

10. Install R3, 470 ohm [yellow-violet-brown].

DN1• 12

DN1 specifications

Ramsey Electronics DN1 is a versatile and compact digital audio transmitter that caters to a variety of audio transmission needs. It is designed for hobbyists, educators, and DIY enthusiasts looking to create their own wireless audio systems. The DN1 offers a reliable solution for transmitting audio signals over short distances without the clutter of wires.

One of the main features of the DN1 is its ability to transmit audio in the FM band, which provides clear sound quality and minimizes interference. The device operates at a frequency range of 88 to 108 MHz, allowing users to choose the optimal frequency for their specific environment. This adaptability makes it suitable for applications like personal broadcasting, classrooms, or small events.

The DN1 is equipped with a simple-to-use interface, featuring adjustable audio input levels and an LED indicator for power and modulation status. It supports both mono and stereo audio inputs, making it a flexible option for various audio sources. Users can connect the transmitter to devices such as audio players, microphones, or computers, which allows for seamless integration into existing setups.

Another significant characteristic of the DN1 is its compact and lightweight design, making it easy to transport and mount in different locations. Its robust construction ensures durability, making it ideal for both indoor and outdoor use. This makes the DN1 an excellent choice for users who need a portable solution for DIY projects or presentations.

The device operates on a low-power consumption model, which is not only environmentally friendly but also cost-effective. It can be powered by a standard 9V battery or an external power supply, adding to its convenience and versatility.

In terms of performance, the DN1 boasts a transmission range of several hundred feet in optimal conditions, ensuring that audio signals remain strong and consistent even in larger areas. This range, combined with its ease of use, makes it an appealing option for those looking to broadcast audio without the limitations of wired connections.

Overall, Ramsey Electronics DN1 stands out as an innovative transmitter that brings together user-friendly features, excellent audio quality, and practical design. Whether for personal use, educational purposes, or event hosting, the DN1 meets the demands of modern audio transmission needs, allowing users to experiment and expand their audio capabilities with ease.