Modular Receiver for LF/VLF Bands

Larry Coyle, K1QW, published a 2-part article in QST (Nov & Dec 2008) that presents a high performance LF/VLF receiver design. The December portion of this article describes the use of a software defined radio I-Q detector module as part of the overall design. Larry gives a good high-level explanation of how the detector works, and also highlights the versatile DDS-60 that serves as the receiver's software-controlled VFO.

Perseus Receiver

The December 2008 issue of QST has a product review of the Microtelecom Perseus Software Defined Receiver. Its frequency range is 10 kHz to 30 MHz, and reception modes are SSB, CW, AM, FM. Since this receiver uses a high-speed ADC to convert the received RF signal to data, and derives the I and Q signal streams internally, it is able to interface with a PC via USB interface, rather than a sound card interface.

The Perseus is available from SSB Electronic USA.

SDR - Contesting & Bandscope

The DH1TW web site covers two topic areas that may be of interest to hams interested in exploiting SDR capabilities.

- A presentation about the applications of SDR for contesting incorporates a nice high-level summary of the technologies and SDR products that may facilitate contest activity.

- The implementation a 20 kHz wide bandscope using an inexpensive SDR kit connected to an IF stage of the FT-1000MP transceiver is documented.

The latter application is discussed regularly in Yahoo's Softrock-40 Interest Group for various receiver / transceiver brands and IF ranges.

SDR-14 Receiver

This receiver is the "big brother" of the SDR-IQ. It also samples directly the RF band of 500 Hz to 30 MHz using a 66.6 MHz ADC, but includes a direct input port to also allow sampling of signals up to 230 MHz. Like the SDR-IQ, it converts the digitized signal data to I and Q format for transfer to a PC via USB 2.0 interface.

It provides a spectrum display of up to 30 MHz wide and uses SpectraVue (proprietary) software. Software drivers are available for Windows and Linux for use by developers. The SDR-14 web page provides additional details.

The SDR-14 was reviewed in the December 2005 issue of QST. Its price class as of this writing was $1099.

SDR-IQ Receiver

This receiver covers the range of 500 Hz to 30 MHz using a 14-bit A/D converter running at 66.6 MHz. The signal data are converted to I and Q format for interface to a connected PC via USB 2.0 rather than the commonly used sound card interface.

It provides a spectrum display 190 kHz wide and uses SpectraVue (proprietary) software. Software drivers are available for Windows, Linux, and Mac operating systems for use by developers.

More details are here. The price class at this writing is $499.

Applications of the SDR-IQ and SDR-14 are described at the RFSPACE NEWS BLOG.

Perseus SDR Receiver

Several SDR receivers are available as commercial products. Among them is the Perseus, which can tune and display an 800 kHz segment in the range of 10 kHz to 30 MHz.

FlexRadio Transceiver

A well-known example of an SDR transceiver is the FlexRadio FLEX-5000. This transceiver covers the HF and 6-meter ham bands with 100 W output, and general coverage receive. Reviews were published in the February 2008 issue of CQ Magazine and in the July 2008 issue of QST. A review on eHam.net is available here.

Introduction

Software Defined Radio has a wide range of implementation in HF amateur radio today. Available applications range from commercially-produced full-powered transceivers and receivers costing thousands of dollars to simple QRP transceivers and receivers in kit form that are priced in the tens of dollars. The selected links on this blog provide SDR background information and views of current activity.