Software Defined Radio
RTL-SDR report – 2
The RTL-SDR dongle is being reported in this commentary. Connecting the unit is straight forward. A USB extender cable is useful for reducing the strain that may be placed on the computer USB cable and for convenience in accessing the port on a desktop computer. Various SMA to HF or BNC adapters are available for connecting an antenna. Some units are sold with rabbit ear antennas and cables.
The RTL-SDR dongle is being reported in this commentary. Connecting the unit is straight forward. A USB extender cable is useful for reducing the strain that may be placed on the computer USB cable and for convenience in accessing the port on a desktop computer. Various SMA to HF or BNC adapters are available for connecting an antenna. Some units are sold with rabbit ear antennas and cables.
The software download went smoothly and was placed in its own folder and then expanded from the zip file. On one occasion it was necessary to do the install a second time to get the zadig file to create. After following directions on installing the driver, the radio was displayed and ran in the FM broadcast band. With decent playback equipment the audio quality will surprise you.
After changing the SOURCE to the Q output, HF frequencies were available. SSB and CW signals sounded fine.
The unit is very convenient and useful for casual SWLing from DC to daylight, using as inexpensive spectrum analyzer or for portable situations like locating RFI or direction finding.
After changing the SOURCE to the Q output, HF frequencies were available. SSB and CW signals sounded fine.
The unit is very convenient and useful for casual SWLing from DC to daylight, using as inexpensive spectrum analyzer or for portable situations like locating RFI or direction finding.
Notes:
An S9 signal (-73db) is close to -25 on the provided display scale.
Using the technique of using the DSB mode (double sideband) and tuning to zero beat the resulting upper and lower 1000 Hz sideband signals the radio showed to be 14Hz high. K5IP reports when using the direct sampling input the frequency is dead on.
Tom, W0IVJ, compared this unit with a Perseus SDR receiver and found the noise floor with an S9 signal injected to be significantly higher.
An S9 signal (-73db) is close to -25 on the provided display scale.
Using the technique of using the DSB mode (double sideband) and tuning to zero beat the resulting upper and lower 1000 Hz sideband signals the radio showed to be 14Hz high. K5IP reports when using the direct sampling input the frequency is dead on.
Tom, W0IVJ, compared this unit with a Perseus SDR receiver and found the noise floor with an S9 signal injected to be significantly higher.
Some have reported that strong broadcast station signals degrade the performance. We may continue our work with this unit by making band filters. K5IP reports using an ordinary antenna tuner made an improvement.
A temporary e-mail reflector was created so members could share information and questions without disturbing the Club’s regular reflector.
A temporary e-mail reflector was created so members could share information and questions without disturbing the Club’s regular reflector.
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This is a display of the 10mHz WWV signal. It show the carrier in the center and upper and lower 1000Hz tone sidebands as well as the 2000Hz and 3000Hz harmonics.
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A FM broadcast station with the FM signal in the center and two data signals on the sides. The adjacent signals are other FM stations.
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A screen shot of the display of the 40 meter phone band. Band conditions were quite poor and many signals were close to the noise level.
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EST 05/09/19
04/22/19
After my recent e-mail to the Club I feel there is enough interest in SDRs (software defined radio) to form a group to share experiences. I'm looking for someone to lead the project.
*Is that you?*
After my recent e-mail to the Club I feel there is enough interest in SDRs (software defined radio) to form a group to share experiences. I'm looking for someone to lead the project.
*Is that you?*
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General plan for the group.
Members will purchase an RTL-SDR (RTL2832U R820T2) or similar unit on line for about $22. They may want a SMA/UHF or SMA/BNC antenna connector. There are options available from rigid one piece adapters to flexible cables with the appropriate connectors. I bought a pair of 6" adapter cables for $7 on line. I like using a 6" USB extender cable between the unit and the computer to ease physical strains on the connectors. I bought ten of then on line and and will offer the excess to those first requesting one. Software is downloaded on line for free. An SDR radio essentially takes a range of the radio spectrum and passes it to the computer to process. The results are amazing. This particular dongle will work from below the AM broadcast band up to a gigahertz decoding AM, WFM, NFM (repeaters, etc.) SSB, CW. Uses for the radio are many. You can do a lot with it such as just listening to FM broadcast, having a spectrum analyzer, SWL or go portable for interference locating or transmitter hunting. This project does not require construction. It is reasonably inexpensive. It is a good introduction to a new technology. I plan to create a reflector for participating members so they can share information or ask questions without overloading the Club Reflector. *Are you interested in joining the group project?* Reply to [email protected] Ed This is the RTL-SDR dongle many will be using with a short USB extender cable and flexible SMA to UHF antenna connection adapter. Make sure you get a unit that can receive HF if you want to use it in the lower ham bands.
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Interested in SDRs?
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Both sides of the card that come with the RTL-SDR unit. It provides several references for installation and use documentation.
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