The FlexRadio SDR-1000™

SDR-1000™ Radio (Click image to enlarge)

The SDR-1000™ Software Defined Radio (SDR) is a radio whose modulation waveforms are completely defined in software. Traditional analog radios are fixed in capability for all time.  Since all of their functionality is hard wired into the radio, there is little ability to upgrade.  Many modern radios add proprietary digital signal processing (DSP) chips to traditional analog radio architectures to provide signal-processing functions with limited or no capability of upgrade. 

The FlexRadio SDR-1000™ is the first open source software, amateur radio transceiver to incorporate the scalable DSP performance of a personal computer (PC) and sound card to perform all modulation, demodulation, and control functions of the radio.  The general purpose PC architecture now vastly outperforms even the best proprietary DSP chips, with cost/performance constantly improving.  In addition, the professional audio market is driving significant improvements in sound card technology.  The SDR-1000™ takes advantage of these trends to provide upgradeable hardware and software performance.

Steve Ford, Editor, writes in April 2005 issue of QST,

“The debut of the FlexRadio SDR-1000™ opens a new chapter in the history of Amateur Radio. I’m not indulging in hyperbole by making such a statement – it is a fact. For the first time in ham history, you can purchase ‘off the shelf’ an HF and 6 meter transceiver that uses software to define its functionality – a software defined radio.”

Receiver Frequency Range 12KHz-60MHz (Requires external user supplied pre selector for best operation below 160M)
Transmitter Frequency Range 160M-6M Bands (2M transverter IF optional)
IP3 - Third Order Intercept (2KHz Tone Spacing, 14.0MHz, 500Hz BW, Medium Preamp Gain, Delta 44 sound card) +26 dBm
Two Tone, Third Order Dynamic Range (2KHz Tone Spacing, 14.0MHz, 500Hz BW, Medium Preamp Gain, Delta 44 sound card) 99 dB
MDS (14.2MHz, 500Hz BW, Delta 44 sound card) -130 dBm High Preamp, -121 dBm Med Preamp
Minimum Tuning Step 1Hz
Direct Digital Synthesizer (DDS) Clock 200Mhz, <1ps RMS jitter
Max. Receive Bandwidth 48kHz (Limited by sound card)
Transmit Power 1 W or 100W HF versions 160-10m with optional amp (40W continuous carrier), 500mW 6m.  Note: 1W models may be upgraded at a later date with the optional SDR-100WPA module.
Control Interface PC Parallel Port (DB-25 connector) or optional USB to Parallel adapter
Rear Panel Control Outputs 15-pin "D" connector for external amplifier and band control relays
Input Controls PTT foot switch, Code Key, Microphone
Sound Card Interface Line In, Line Out, Speaker Out, Microphone In
Enclosure Dimensions 10" W x 9.5" D x 4.5" H (24.1cm x 25.4cm x 11.4cm)
Power Supply Requirement 13.8VDC @ 1.25A (Max) for 1W version. 25A (Max) with optional 100W PA

Supported PC Configurations

Operating System

Windows 2000 or Windows XP, User developed Linux version available


Min: 1.5GHz   Recommended: 3.2GHz+


Min: 512MB   Recommended: 1GB+

Recommended Sound Cards (See Important Note Below)

PCI: M-Audio Delta 44

Firewire (1394a): Edirol FA-66

How to select the right sound card?

Don't wait.  Order your SDR-1000 Today!

Important Note:

Proper operation of the SDR-1000™ depends on the use of a sound card that is officially supported by FlexRadio Systems.  Refer to the Supported PC Configurations above to determine which sound cards are currently supported.  Use only the specific model numbers stated on the website because other models within the same family may not work properly with the radio.  Officially supported sound cards may be updated on the website without notice.  If you have any question about the sound card you would like to use with the radio, please email or call us at 512-250-8595.  NO WARRANTY IS IMPLIED WHEN THE SDR-1000 IS USED WITH ANY SOUND CARD OTHER THAN THOSE CURRENTLY SUPPORTED AS STATED ON THE FLEXRADIO SYSTEMS WEBSITE.  UNSUPPORTED SOUND CARDS MAY OR MAY NOT WORK WITH THE SDR-1000.  USE OF UNSUPPORTED SOUND CARDS IS AT THE CUSTOMERS OWN RISK.


The SDR-1000 comes with PowerSDRTM software that performs all DSP and control functions for the radio.  The software is provided open source under the GNU General Public License (GPL). This means that customers have the ability to improve performance and add functionality to the radio with redistribution rights defined under GPL.  Further, FlexRadio Systems provides a constant stream of enhancements that incorporate both internal and customer supplied code.  Customers simply download and install free software updates from the FlexRadio website.

"Used SDR-1000s do not exist. The radio becomes brand new each time you download the latest program release.”  Willi, SM6OMH

Select the PowerSDR menu option above under Products for additional information about the SDR-1000's software.


World's Best Narrow Spaced Dynamic Range

99dB of two-tone, third order dynamic range and +26dBm IP3 at 2 KHz spacing (14 MHz, 500 Hz bandwidth, Medium Preamp Setting, M-Audio Delta 44 sound card) make the SDR-1000™ the best performing narrow-spaced radio on the amateur radio market today.  Closely spaced two-tone third order dynamic range, combined with extremely low local oscillator phase noise is the primary factor that determines the performance of modern receivers.  The SDR-1000™ incorporates a novel Quadrature Sampling Detector (QSD) that offers significantly higher dynamic range than traditional mixers.  Further, by using a single conversion from RF to audio frequencies, other sources of nonlinearity are eliminated as compared to multi-conversion receivers.  The SDR-1000™ also uses a very low phase noise oscillator and direct digital synthesizer (DDS) to minimize reciprocal mixing with large adjacent signals.  This means that you can work the weak signals in the presence of nearby strong signals.

Real Time High Resolution Spectrum Display with Click Tuning and "Drag and Set" Filter Settings.

PowerSDR(TM) software (Click screenshot image to enlarge)

The Real-Time Panadapter spectrum display allows you to view signals up and down the band at up to 50 frames per second with ~10Hz resolution.  When calibrated with an accurate signal generator, the spectrum display and associated dBm power meter provide signal location and measurement capabilities comparable to expensive lab test equipment.  Phase, Waterfall, and Histogram display modes are also provided.

Click on the Spectrum Display to Tune instantly to any visible signal.  Click tuning works in all modes and works especially well for centering the desired signal in the selected filter’s passband.

Drag and Set Filter Settings allows to to "grab" the receive filter edges with your mouse and dynamically create any filter you want with any offset when using the Panadapter display - as narrow or wide as you want in any mode.

Contesting and DX chasing become a snap when you can see the signal, click to tune, make the contact, and move off to the next one.  For VHF and up, the same features let you find off-frequency signals in seconds and work them with ease.

Brick Wall No Ring Filters and No Pump AGC

2048 tap DSP Filters Provide a 1.35:1 Shape Factor for a 500 Hz filter and 1.06:1 for a 2.6 KHz filter (3dB to 60dB BW).  Strong signals simply disappear within a few Hertz of the filter cutoff frequency.  The radio’s unparalleled selectivity lets you enjoy the bands with much less interference from adjacent stations.  The filter size can be set by the user from 256 to 2048 taps to allow the tradeoff between filter shape factor vs. latency (time delay through the filter).  Ten standard filter bandwidth buttons plus two custom filters with variable high and low cutoff are provided.

No-ring Filters Down to 25 Hz Bandwidth Aallow You to Pull in Extremely Weak Signals Even Among Strong Adjacent Stations.  The narrow filters make on the air CW signals sound amazingly like a code practice oscillator. 

All digital AGC is Performed After the Brick Wall Filter to eliminate compression or "pumping" of weak desired signals by strong adjacent signals.  The AGC threshold may be set by the user to allow quiet operation under varying band conditions. 

Single Control Variable Bandwidth Filter Along with IF Shift with Auto Center allows rapid customization of the filter to eliminate QRM.  The variable bandwidth control directly programs one of the custom filter buttons for easy recall.

Impulse Noise Subtraction and DSP Noise Reduction

DSP Impulse Noise Subtraction Virtually Eliminates Distortion caused by traditional noise blankers by digitally replacing noise pulses with an estimate of the real signal.  Multi-tone automatic notch filter and DSP noise reduction are also provided to further improve the listening experience.

Graphic Equalizer, Compander, Pre Filter Compression, and Variable Bandwidth Filter

The 3-Band Graphic Transmit and Receive Equalizer and Continuously Variable Bandwidth Transmit Filter allow you to customize your signal for band conditions, operating style, and mode.  All compression and ALC processing occurs before the final brick wall transmit filter to virtually eliminate splatter.  For maximum talk power, either a feed-forward compressor and a compander may be selected from the console.

 Built-in Iambic, Keyboard and Memory Keyer

The built in CW keyer provides semi break-in modes for iambic A & B, non-iambic, keyboard, and memory operation at up to 50 WPM.  World-class narrow-spaced IMD performance and brick wall filters, no ring filters down to 25Hz bandwidth make this transceiver a joy to use on CW.

 CAT Control & Virtual COM Ports Allow Integration of Logging and Digital Mode Software

Virtual COMM Port Software Allows Almost Any Logging or Digital Mode Software to be Used on the Same PC Without Cables.  This eliminates external CAT control wiring by creating a software connection between PowerSDR™ and other amateur radio applications.  PowerSDR™ software emulates the Kenwood CAT command set in its basic compatibility mode, which means that most amateur radio applications run right away.  An extended command set is also available that allows software vendors to take advantage of the advanced features of the SDR-1000™.  MixW, Ham Radio Deluxe, and WriteLog are just a few of the applications known to work with the SDR-1000™.

Record and Playback 96kHz of Real-Time Spectrum

Now you can go back in time using the wave recording and playback features of the PowerSDR™ software.  All of the signals within the bandwidth of your sound card can be recorded to the hard disk to be played back at any time.  You can tune in any station within the full 96kHz of recorded signals.  This is handy for recording beacons, contests, important DX contests, and radio demos.

Add the Optional Automatic Tuning Unit and 2 Meter Transverter

The SDR-ATU is an optional integrated wide-range switched-L tuning network for the SDR-1000. Based on an OEM version of the LDG Z-100, it provides fully automatic antenna tuning across the entire HF range.  It will tune dipoles, verticals, Yagis or virtually any coax fed antenna over a wide impedance range.  Features include: automatic matching of antennas from 6-800 Ohms (10:1 SWR), 200 memories for instant return to previously tuned frequencies, continuous coverage from 1.8 to 54 MHz and PowerSDR control of Bypass, Full Tune, and Memory Tune.

The DEMI144-28FRS is an optional integrated 2m transverter.  Designed as a 2m IF for microwave transverters, it provides high dynamic range operation from 144-146 MHz.  It provides 0dB gain and +17dBm LO drive on receive with a 3.5dB NF so that it can easily handle the output from other transverters.  Power output is 50-100mW on transmit and can be reduced by the front panel power control.

You have 2 baseline options when purchasing an SDR-1000:
  • 100 Watt Software Defined Transceiver - Fully Assembled/Tested
  • 1 Watt Software Defined Transceiver - Fully Assembled/Tested
Note: Includes parallel control cable. Recommended Delta 44 sound card and PC bundles can be ordered below.

NOW Available Bundled with Dell PC and High Performance Sound Card

FlexRadio now offers a complete system in which the SDR-1000™ is bundled with a Dell personal computer and high performance sound card.  The PC comes with the sound card installed, software loaded, and ready to operate.  These Pentium 4 systems are available with optional flat panel monitors up to 19 inches.  The PCs are backed by Dell's warranty and support services.  Call us for details.

FlexRadio Systems Terms and Conditions of Sale

The SDR-1000™ requires the use of an officially supported sound card and PC configuration. Please refer to the supported PC configurations on the website before ordering. (2) SDR-1000 includes Amateur Radio band transmit capability, which requires a valid amateur radio license; therefore you must provide your Amateur Radio for all models with transmission capability. (3) Product may be returned for full credit within 30 days from shipment if it is returned in new condition and in the original packing materials.

FlexRadio Systems 1-Year Limited Warranty

This warranty is effective as of the date of first purchase by the consumer. Before requesting warranty service, you should complete a careful review of the most recent version of the Troubleshooting Section of the Operating Manual on the customer download site. What is covered: During the first year after date of purchase, FlexRadio will replace defective parts free of charge (post-paid). We will also correct any failure caused by defective parts and materials. You must send the unit at your expense to FlexRadio™ (see above). FlexRadio will pay return shipping. What is not covered: This warranty does not cover correction of assembly errors or misalignment; repair of damage caused by misuse, negligence, or builder modifications; or any performance malfunctions involving non-FlexRadio accessory equipment. The use of acid-core solder, water-soluble flux solder, or any corrosive or conductive flux or solvent will void this warranty in its entirety. Also not covered is reimbursement for loss of use, inconvenience, customer assembly or alignment time, or cost of unauthorized service. Limitation of incidental or consequential damages: This warranty does not extend to non-FlexRadio equipment or components used in conjunction with our products. Any such repair or replacement is the responsibility of the customer. FlexRadio will not be liable for any special, indirect, incidental or consequential damages, including but not limited to any loss of business or profits. Proper operation of the SDR-1000™ depends on the use of a sound card that is officially supported by FlexRadio Systems. Refer to the Supported PC Configurations on the FlexRadio Systems website to determine which sound cards are currently supported. Use only the specific model numbers stated on the website because other models within the same family may not work properly with the radio. Officially supported sound cards may be updated on the website without notice. NO WARRANTY IS IMPLIED WHEN THE SDR-1000 IS USED WITH ANY SOUND CARD OTHER THAN THOSE CURRENTLY SUPPORTED AS STATED ON THE FLEXRADIO SYSTEMS WEBSITE. UNSUPPORTED SOUND CARDS MAY OR MAY NOT WORK WITH THE SDR-1000. USE OF UNSUPPORTED SOUND CARDS IS AT THE CUSTOMERS OWN RISK.

Enter a HelpDesk Ticket
Knowledge Center
FlexReady™ PCs & Services
FlexRadio Videos
FLEX-3000 Features
FLEX-1500 Features
Product Comparison Matrix
FlexRadio FAQs

FlexRadio Users Net Schedule

Sundays @ 2 PM Eastern,
1 PM Central on 14.329 MHz
 ± QRM

We are running a test on
Echolink, with node 79336,
open conference

The net is also simulcast on the Internet using CQ100 from @ 14.329 and on EchoLink node 79336.

2008 Hamfest Pictures
2007 Hamfest Pictures
2006 Hamfest Pictures
Early Hamfest Pictures

::: CONTACT US :::         ::: PRIVACY POLICY :::

©2005-2013 FlexRadio Systems
FlexRadio Systems is a registered trademark
SDR-1000, FLEX-5000, FLEX-3000, FLEX-1500, FLEX-6000, SmartSDR, PowerSDR, FlexWire, ClickTune, MultiRX, PanaFall, PanaScope and FlexReady are trademarks of FlexRadio Systems
FireWire® and the FireWire logo are registered trademarks of Apple Computer Inc., under license
FlexRadio Systems, 4616 W. Howard Lane Suite 1 - 150 Austin, TX USA 78728
All rights reserved
Website development by Paradigm Software Group, Inc.