Tagged: rtl2832u

New RTL-SDR + Upconverter Available

BA5SBA, the creator of the Chinese direct sampling kit (and fully assembled version) recently wrote in to let us know about a product that he is now building. His new product is a fully assembled RTL-SDR + Upconverter. The upconverter design uses a DBM balanced ring mixer design which he writes makes less noise and has greater dynamic range. He also writes that compared to direct sampling the upconverter model should have greater sensitivity as it allows use of the R820T LNA. His design uses a 40 MHz local oscillator, comes with increased RF input protection and comes in an aluminium case.

BA5SBA's new upconverter can be found for sale on eBay for around $80 USD.

We also posted previously about BA5SBA's direct sampling kit here.

RTL-SDR + Upconverter in a box by BA5SBA
RTL-SDR + Upconverter in a box by BA5SBA
Example of reception
Example of reception

Amateurradio.com RTL-SDR Giveaway

The guys at the AmateurRadio.com blog have teamed up with Nooelec to bring everyone a worldwide competition giveaway of 20 RTL-SDR prizes. The top prizes include the rare E4000 chip tuners, ham-it-up upconverters, adapters and aluminium enclosures while the regular prizes include an R820T2 RTL-SDR set.

To enter the competition all you need to do is leave a comment on their competition post. The competition is open for one week from 11 December 2014 to 18 December 2014. The complete list of prizes are quoted below.

Three (3)
Complete NESDR XTR HF SDR packages including:
NESDR XTR SDR Set (E4000 chip)
Ham It Up upconverter
Upconverter Enclosure (silver)
Male MCX to male SMA pigtail (SDR cable)
Male SMA to female BNC adapter (antenna adapter)
Estimated $129.95 value

Five (5)
Complete NESDR Mini 2 HF packages including:
NESDR Mini 2 SDR set
Ham It Up upconverter
NESDR Mini 2 enclosure (silver)
Upconverter enclosure (silver)
Male MCX to male SMA pigtail (SDR cable)
Male SMA to female BNC adapter (antenna adapter)
$111.95 value

Twelve (12)
NESDR Mini 2 SDR sets
$25.95 value

AmateurRadio.com and NooElec Giveaway
AmateurRadio.com and NooElec Giveaway

Receiving WSPR with the RTL-SDR

Recently RTL-SDR.com reader DE8MSH wrote in to let us know about his experiments with receiving WSPR with his RTL-SDR. WSPR is an acronym for “weak signal propagation reporter” and is a software program and RF protocol designed for very weak signal radio communications between ham radio users. With less than 5W of transmitting power, a WSPR signal could potentially be copied all over the world.

To receive WSPR, DE8MSH used a direct sampling modified RTL-SDR dongle together with a 9:1 unun, 10m RG58 coax cable from RTL-SDR to unun and a 12m wire antenna outside his house. Then by using SDR# together with the WSPR software he is able to copy signals from all over Europe and Canada/USA from his home in Germany.

Some Received WSPR Locations
Some Received WSPR Locations
WSPR Report Information Including Distance
WSPR Report Information
The WSPR Software
The WSPR Software

Listening to FreeDV Digital Speech with an RTL-SDR

Over on YouTube user BSoD Badgers has uploaded a video showing his reception of FreeDV digital speech at 14 MHz. He uses SDR# combined with the FreeDV software to decode the signal.

FreeDV is a open source software application that allows digital speech to be sent at HF frequencies in a 1.25 kHz wide signal. The same software can be used on the receiving end to decode the signal into speech.

Characterizing the SWR of an Antenna with a Noise Source and an RTL-SDR

In our last post Adam Alicajic showed us on YouTube how to determine the frequency response of an RF filter using just a wideband noise source an LNA and an RTL-SDR dongle.

In his latest video Adam shows how the SWR of an antenna can be measured using almost the same low cost equipment. One additional piece of hardware required to measure the SWR is a directional coupler which can be bought on Ebay for about $10 USD.

SWR stands for "standing wave ratio" and is a measure that can be used to tune an antenna for a particular frequency. The closer the SWR is to 1:1 at the designed antenna frequency, the better the antenna will receive (and transmit).

In his video Adam shows how he measures the SWR of an ADS-B antenna which he has built and is selling. His results show that the antenna has an SWR of 1:1.02 at 1090 MHz which is quite good.

DIY Characterize the antenna Retrurn Loss / SWR with the DVB-T SDR

Characterizing RF Filters with a Noise Source and RTL-SDR Dongle

Over on YouTube RTL-SDR experimenter Adam Alicajic has uploaded a video showing how it is possible to use the RTL-SDR as a tool to measure the frequency response of an RF filter. To do this he uses a noise source circuit which produces wide band white noise connected to an LNA4ALL, connected to the RF filter and finally connected to the RTL-SDR. Then using the Touchstone spectrum analyzer software he does a 300 MHz bandwidth sweep over a section of the spectrum which shows the response of the filter.

The noise source can be built from a simple diode based circuit as shown in a previous post, or if you have the Ham-it-up upconverter you can buy the parts for the noise generator part of the circuit.

In his video he shows the frequency response of a 145 MHz helix filter, a coax notch filter and a 1090 MHz home brew bandpass filter.

http://www.youtube.com/watch?v=X_gd2gWyGi4
http://www.youtube.com/watch?v=UvdaURc01Ts

More filters and DVB-T dongle

Monitoring House Power Usage using an RTL-SDR

Home automation enthusiast Bruce Winter has recently posted on his blog about how he uses the RTL-SDR as part of his home automation system to automatically monitor his power (and solar power generation) usage. Many home power meters are now wireless which allows meter readers to gather power usage data from afar.

To gather the power usage data he used an RTL-SDR connected to a PC running rtlamr, which is software that can read data from ERT compatible power meters that transmit in the 900 MHz ISM band. He also uses some custom code he wrote that automatically plots the data over time and allows him to integrate it with his home automation system. In addition to his post he also uploaded a video shown below that shows his system in action.

Monitoring house power using a $20 RF RTLSDR USB stick

New Windows AIS Decoder For the RTL-SDR: AISRec

Over on YouTube user Jane feverlay has uploaded a video showing a new AIS decoder called AISRec for Windows that he has developed.

AIS is an acronym for Automatic Identification System and is a system used by ships to broadcast position and vessel information. By monitoring AIS transmissions with the RTL-SDR we can build a boat radar system. We have a tutorial on this here.

The new software is not free, but he offers a trial version that limits the run time to 20 minutes and 5000 max messages. The paid version removes these limits and also decodes both AIS channels simultaneously. The program monitors data from the RTL-SDR and sends decoded data out via UDP. Software such as OpenCPN can then be used to display the AIS data on a map.

We tested the trial version on our machine and found that it worked well at decoding AIS messages. To download the trial go to http://pan.baidu.com/s/1pJiEzEV and enter the code kn44. The download site is in Chinese, but it is obvious where to enter the code. We found the software to be virus free, but remember to always scan unknown software like this yourself. The full price of the software is unknown, but purchasing instructions are given in the trial download readme. The author also writes that his software now supports the Airspy, but not in the trial version.

Note that we discovered that the software doesn’t use a PPM correction setting as expected. Instead it uses a frequency shift setting. To set the shift in the AISRec.ini file, we had to calculate freqshift = 162.025 MHz – frequency of the second AIS channel as shown in SDR# with no PPM correction set.

Another similar software program that was released earlier is PNAis.