USING YOUR RECEIVER:

In your first tests, you might feel that tuning in CW and SSB stations by turning the control shaft seems tricky. Don't despair! The addition of a simple knob to the final version of your kit will result in more comfortable tuning right away. Also, the larger the knob, the easier the tuning is. Even smoother control can be accomplished by a vernier dial, which will also provide calibration marks. Finally, if you intend to use this receiver only for monitoring or working a very specific frequency range, you can add a resistor in series with the tuning control to achieve the bandspread you want for your own application. For details, please see the upcoming section, Notes to Experienced QRP Builders.

We want you to enjoy this economical receiver, whether you use it for portable listening or as a base for easy experimentation. Isn’t it amazing the performance that can be achieved with just two IC chips?

•TUNING SSB SIGNALS

As you know, the protocol for the 160 - 80 - 40 Meter Bands is lower sideband (LSB), with Upper Sideband (USB) used for 40 - 18 - 15 - 12 - 10 Meter SSB. To check or ‘scan’ a given band for SSB signals, tune your HR40 up from the low end for USB signals and down from the high end for LSB.

•CW OPERATION

A direct-conversion receiver lets you hear equal ‘sidebands’ on either side of the zero-beat ‘null’ of the exact frequency of the signal to which you are listening. Therefore, when adjusting the frequency of your companion Ramsey QRP transmitter, be certain that you have in fact tuned to the other station’s lower sideband. The two stations will actually be several KHz apart. Because this receiver’s oscillator is not shared with a transmitter, as in transceivers, there is no need for separate RIT (receiver incremental tuning).

•ON THE AIR TRANS-RECEIVING

Let’s assume that you plan to use this receiver together with a Ramsey QRP transmitter, which provides an RF protected receiver antenna jack. While the receiver will be protected from RF damage from the transmitter, do not expect to monitor your own signal on this receiver while transmitting unless you are a QRP design expert and do not care about future factory service from Ramsey. Even with the circuit protection, the RF signal is just too much for the SA602.

The transmitter signal overpowers the SA602, disrupting the internal oscillator. However, the receiver can handle the output of a crystal oscillator or VFO for frequency spotting purposes.

HR40 • 16

Page 15 Page 17
Page 16
Image 16
Ramsey Electronics HR40 manual Using Your Receiver, Tuning SSB Signals, CW Operation, On the AIR TRANS-RECEIVING
Page 15 Page 17

HR40 specifications

The Ramsey Electronics HR40 is a versatile and high-performance FM transmitter that has gained recognition among hobbyists and professionals looking to broadcast audio signals. With its robust features and user-friendly design, the HR40 stands as an excellent choice for a range of applications, from low-power broadcasting to personal audio projects.

One of the standout features of the HR40 is its frequency range, typically allowing for transmission on the FM band from 88 to 108 MHz. This broad range ensures compatibility with a variety of receivers and allows users to select an optimal frequency for their needs, minimizing potential interference. The transmitter is designed to offer excellent audio fidelity, with a frequency response that meets and exceeds industry standards, ensuring clear and crisp sound quality.

The HR40 utilizes advanced modulation techniques, which contribute to its performance in terms of signal clarity and range. The use of frequency modulation allows the HR40 to transmit audio signals with minimal distortion, even at higher volume levels. Additionally, the transmitter is equipped with a built-in audio preamplifier, which enhances audio quality by providing a clean and powerful signal before transmission.

Another notable characteristic of the HR40 is its adjustable output power. Users can modify the power level to suit their specific broadcasting needs, whether for indoor use or outdoor applications. This flexibility is particularly useful in managing transmission range, allowing users to tailor their setup without excessive overkill or underperformance.

The compact design of the HR40 also stands out, making it a popular choice for those who need a portable broadcasting solution. The unit is lightweight and easy to transport, while its durable construction ensures longevity and resilience in various environments.

In terms of ease of use, the Ramsey Electronics HR40 offers simple installation and operation. It comes with a clear instruction manual, allowing users to set up their transmitters quickly. The intuitive interface and minimal setup requirements enable beginners to jump right in, while advanced users can take advantage of its expandability and customization options.

Overall, the Ramsey Electronics HR40 combines user-friendliness with a range of powerful features aimed at both amateur and experienced broadcasters. Its excellent audio quality, adjustable output power, and compact design make it a favorite for many seeking reliable FM transmission capabilities.
Top Page Image Contents