Category: Other

December 18, 2013

Review of the TCXO Modified RTL-SDR Dongle

A few days ago we had a post about a modified RTL-SDR dongle for sale which has the low quality 28.8 MHz oscillator replaced with a high quality 28.8 MHz temperature controlled oscillator.

Nobu Saitou, the creator of these dongles has sent us a sample to review. On the inside of the dongle the 28.8 MHz crystal has been removed, and replaced with a 28.8 MHz temperature controlled oscillator. The desoldering of the old oscillator and soldering of the new TCXO appears to be neatly and professionally done.

After plugging in the dongle and firing up SDR#, we tuned to a known trunking control channel at 152.850 MHz and measured the frequency offset. It turns out that with the TCXO no frequency correction was required at all. I believe that from Nobu’s blog post, this oscillator can have a max deviation of +-2 PPM, which is incredibly small.

TCXO Dongle with Zero PPM correction required

We compared this result to a standard dongle with the original oscillator and found the frequency offset required to be 44 PPM.

As the dongle heats up from use, the oscillator will experience thermal drift, causing the frequency offset to change. The TCXO should be immune to this problem due to it’s temperature compensation circuitry. To test the temperature compensation, we cooled both a TCXO dongle and a standard dongle down in a refrigerator first to simulate cool climate conditions. We then measured the change in PPM offset after 30 minutes of dongle operation. As expected, the TCXO had almost zero drift after 30 minutes (<<1 PPM), whereas the standard dongle had a drift of about 6-7 PPM (approx. 1 KHz drift).

TCXO Oscillator: Frequency drift after 30 minutes

Standard Oscillator: Frequency drift after 30 minutes

The results of this simple test show that the TCXO used in these modified dongles is an accurate and stable frequency source as was expected. If you want one of these dongles they are for sale at the creators Amazon Store (direct link to TCXO product here). Currently it seems that Saitou’s products cannot be sent abroad outside of Japan, but he recommends this agent service for ordering internationally.

Edit: The TCXO can now be bought internationally from 1090mhz.com

December 5, 2013

Nooelec RTL-SDR Giveaway on AmateurRadio.com

AmateurRadio.com has teamed up with Nooelec.com to give away RTL-SDR packages to 10 hams. To be eligible to enter the competition, you must be a registered amateur radio operator, and you must comment on the competition page. The prizes are

Two (2)
Complete HF sets including:
NESDR Mini receiver
Ham It Up upconverter
SMA to MCX cable
SMA to BNC adapter
SMA to PL259 adapter
SMA to F adapter

Two (2)
Complete Touch SDR sets including:
NESDR Nano receiver
SDR Touch license (for Android tablets)
USB OTG micro & mini cables

Three (3)
NESDR Mini receivers

Three (3)
NESDR Nano receivers

The competition runs until the 11th of December.

October 23, 2013

Elusive E4000 RTL-SDR Dongles

Over on the Gough’s Tech Zone blog, Gough has posted about his experiences in trying to obtain an E4000 RTL-SDR. He found that finding a real E4000 on ebay was tough, with most vendors claiming to have “upgraded E4000s” which were in fact R820T’s.

The E4000 tuner is becoming rare as Elonics, the manufacturer has shut down. The newer, still in production R820T tuner is in many ways better than the E4000, but the E4000 is still useful for some applications that require the higher frequencies that it can tune to.

If you want an E4000, we know for sure that Nooelec sells a Terratec version that has the E4000 chip.

August 24, 2013

HackRF vs. BladeRF vs. USRP

To help you decide which of the recently released software defined radios is right for you, blogger Taylor Killian has written an article discussing and comparing the HackRF, BladeRF and new USRP models.

The HackRF, BladeRF and USRP are all high end SDRs which range in cost from $300 (HackRF) to $1100 USD (USRP B210). They differ from the RTL-SDR in that each is specifically designed for the purpose of software defined radio, and they all have large bandwidths and transmit capabilities.

HackRF Jawbreaker Board with Enclosure BladeRF USRP

Submit a Story/Contact

If you would like to submit something that relates to cheap SDR (a project, blog post, something interesting you have found), please email us at [email protected].

We will look at your submission and if we think it is a good fit for our blog make a summary post about it, making sure to link and credit your original source. If you don't have your own website or blog, don't worry, just write about your project in an email and we will host any images or documents related to your project for you. Usually we will get to your submission within a few days.

Please note that we will not accept payments or incentives in return for any type of post except for product samples for an honest review. If you are interested in writing a non-commercial guest post for us, please also contact us on the above email address.

Product/Shipping Support

If you have a general question about RTL-SDRs or SDRs or third party software we ask you to please ask in our forums. If you email us we may not respond to questions about third party software as this should be asked in the forum.

If you need troubleshooting support please first ensure that you have been through our Quickstart guide and the troubleshooting section on it, as well as our V3 users guide. Common questions like how to use the HF mode and how to activate the bias tee are explained on the V3 users guide.

If you have a question about shipping of an item please first read the shipping policy on our store and see if it answers your question. The shipping information is just under our product listings. If it is a request for tracking details please first check your old/deleted/spam mails for the order confirmation email which contains the tracking details. There will have been two emails from our email at [email protected], the second of which contains the tracking details.

If you suspect a lost postal item please contact your local postal agency first and inquire there. They have more information than we have. If they confirm it as lost or not received after a long time then please let us know and we can open an investigation on this side as well. Usually we must wait at least 6 weeks from the date posted before we can open a lost parcel investigation.

For everything else such as confirmed lost postal items, warranty claims and support inquiries that aren't covered by the quickstart or troubleshooting guide then please contact us at [email protected]. We aim to always reply within 1-2 business days. If we don't respond within 3 business days then the mail may have gone to our spam folder. Please try to email again using different keywords. We do check our spam filter once a week just in case, but some messages could still be missed. Remember, if you have questions about third party software, please ask in the forums only.

June 25, 2013

SDR Soundcard Mod

Yesterday we got an email from a reader (Tom) about a soundcard capacitor mod that is useful for SDRs. Tom writes

First you buy one of these sound cards: Creative Soundblaster X-Fi Surround 5.1 Pro USB (various internet sources)

Then you make the following mods: http://www.rfsystem.it/shop/download/SB_Creative_XFi_Pro_USB.pdf

I did the capacitor mod and it makes a HUGE difference, and there is a bonus. Not only do you get an excellent, very low noise sound card, but the drivers include a “what u hear” mixer that works find on Windows 7 so you don’t need to buy a separate virtual audio cable.

The unmodified Soundblaster X-Fi had somewhat fewer noise spikes showing up across the spectrum on SDR# than my internal soundcard. However when I did the capacitor mod, they decreased by a drastic amount. Before I realized the extent of the original internal noise spikes, I wasted time trying to “decode” them – worked about as well as my attempts to communicate with aliens via my dental work.

So now my SDR# display looks really clean and most everything that looks like a signal is a signal. I don’t have before and after pictures, but the ones in the pdf file look like mine.

BTW the capacitor values are probably not all that critical. I used a couple I had laying around – a 1000 uF 16v and a 120 uF 16v. Anyone with some soldering experience and a reasonably small tip can do the mod but it’s a little tricky to position the caps and have the case close properly. The unwary might get polarity confused – the tantalum caps on the board are marked on the positive end and the electrolytics you add are marked on the negative end.

The capacitor mod essentially involves soldering in two more capacitors onto the soundcard PCB. The improvement is more useful for soundcard based SDRs such as the SoftRock, however, in Toms case he found that the capacitor mod also improved his RTL-SDR reception by removing numerous unwanted noise spurs he was seeing.

Since the RTL-SDR is not a soundcard based SDR, in Toms case the external soundcard was probably causing strong interference that the RTL-SDR was picking up, and the capacitor mod treated the noise source.

The mod may also help by giving you a cleaner audio signal, which may help when decoding digital signals.

SDR Soundcard Mod

June 15, 2013

Tip: Effect of Power Sources on the Ham It Up Upconverter

The Ham-It-Up upconverter uses a 5V USB power input. I discovered that different 5v power sources can cause significant interference with this upconverter, and the same effect will probably occur in other upconverters as well.

When the upconverter was powered by mains power via a phone charger, the signals were almost completely drowned out in noise. Powering it with a PC USB port was better, but the PC USB power introduced some other strong noise sources. Powering it with a battery (used a mobile phone with OTG cable) was the best option. There are still some strong noise sources present, but I can probably solve them with better shielding.

Click continue reading to see some comparison images.

Continue reading →

May 18, 2013

List of SDRSharp Plugins

There are a number of SDRSharp plugins that extend its functionality. Here is a collection of all the plugins and download links that I could find.

With modern SDR# installing a plugin is usually a simple matter of copying the plugin files to a subfolder within the SDR# Plugins folder. SDR# should automatically recognize the plugins.

Some plugins might require editing the Plugins.xml file with a text editor such as notepad. These plugins will contain a readme.txt or magicline.txt file that shows what line to add to the Plugins.xml file. Just copy and paste the plugin .dll into the SDR# folder and add the magicline line to the plugins.xml file to install the driver.

We note that SDRSharp can now be downloaded with a community plugin package, which includes many of the plugins listed below. However, sometimes some plugins get broken with newer SDR# versions, so if you have issues with the SDR# community edition, it may be wise to download the vanilla edition and install plugins manually.

Frequency Manager + Scanner and Scanner Metrics and Frequency Entry Package

This is a plugin package which comes with three plugins. It comes with a more advanced frequency manager than the one shipped with SDRSharp.

It also has a scanner option which can quickly scan through a group of your saved frequencies, looking for an active signal.

It also has a scanner metrics plugin, which records frequency activity to a database. Later this database can be analyzed to find out which frequencies are the most active, saving you time searching manually for active frequencies.

Finally, this package also has a frequency entry plugin, which works like the old SDRSharp frequency entry used to work. Basically, it just allows you to choose a center frequency and IF frequency easily by typing it in instead of adjusting it with the mouse.

Download the installation packager here

Fast Scanner

Similar to the Frequency Manager and scanner plugin in that it automatically tunes to active signals above a certain power.

~~Download Link~~ (Original website now dead)

Download Link (via archive.org)

Download Link (RTL-SDR Blog Mirror)

Simple DMR

A simple DMR decoder plugin. No external dependencies, no settings, uses SDR# audio path. Designed for listening to unencrypted DMR channels.Mixes voice from both slots into one channel.

Product/Shipping Support

Frequency Manager + Scanner and Scanner Metrics and Frequency Entry Package

Fast Scanner

Simple DMR

DDE Plugin

QPSK Demodulator

DDE Tracking and Scheduler Plugin

Gpredict Connector

SDRSharp Net Remote

CTCSS Detector and Squelch

DCS Detector and Squelch Plugin

TimeShift SDR

Digital Audio Processor

Audio Processor

IF Notch Plugin

Simple APCO 25

RDS Logger

DSD+ GUI Interface

TETRA Decoder

AUX VFO

Audio Waterfall Plugin

PAL/SECAM TV Plugin

Modified Baseband Recording Plugin

Modified Audio Recording Plugin

IF Recorder Plugin

Level Meter Plugin

CSVUserlistBrowser SDR# Plugin

MPX Output Plugin

Radio Sky Spectrograph Plugin

Aviation band 8.33 Calculator Plugin

Frequency Lock Plugin

Unitrunker Serial Based Trunking Plugin

Passive Radar Plugin

IF Average

Contour Shuttle Support

Visual Tuner Knob

Audio Streaming TCP Server

CalicoCAT Serial CAT Control Plugin

Heatmap Generator Plugin

Magic-Eye Plugin

Multimon-ng Launcher Plugin

RDS Groups to RSDSpy .spy Format File Plugin

Tetra demodulator utils plug-in

Signal diagnostics logger plugin

SDRSharp FFT peek hold plug-in

TETRA demod plug-in network info grid data logger

TETRA plug-in UDP raw data logger with Python

Front End Plugins

Modified R820T FrontEnd with Manual Control and Decimation

File Player

E4000 Gain Mod Enabler

Plugins that no longer work

Orbitron Plugin (Not working with 1400+)

Easy Scanner Plugin (Not working with 1400+)

Audio FFT Plugin (Not Working with 1400+)

ScopeView Plugin (Not working with 1400+)

Simple Audio EQ Balance Plugin (Not working with 1400+)

Signal Strength Logger (Not working with 1400+)

SDR# short-wave.info Plugin (Not working with 1400+)

GlobalTuners SDR# Plugin (Not working with 1400+)

Unitrunker Trunking Plugin (Not working with 1400+)

AutoTuner Plugin (Out of date)

ADSB# Plugin (Missing)

Modified ScopeView Plugin (Missing)

SDR# Dark Mode Plugin

FFT Grabber Plugin

Accessibility Plugin

ExtendedFFT Plugin

Toolbar Plugin

Other Semi-Related

TVSharp

Other Plugin Lists