Tagged: dx

SDR# FM Co-Channel Canceller Added

A few days ago the developer of SDR# added a very useful AM Co-Channel canceller plugin, and just today he has also added a new FM Co-Channel canceller. A Co-Channel canceller allow a user to remove an interfering station, allowing a buried station to be received cleanly. This is especially useful for DXer's where strong local and weak distant overlapping stations are likely to be received at the same time. The plugin works with all SDR# compatible SDRs including the RTL-SDR.

On a related note, we wanted to point out that recently the Airspy website and downloads have been getting flagged by some antivirus software, however we believe these detections to be false positives caused by the very frequent update schedule of SDR#.

SDRSharp FM Co-Channel Canceller

Over on Twitter we've seen a couple of videos from @K7al_L3afta demonstrating how well the new FM Co-Channel canceller works.

SDR# Updates: RTL-SDR Enhanced Mode, AM Co-Channel Canceller for MW DX

Over the past few days SDR# has been updated again adding several new great features. The first is an "RTL-SDR Enhanced" front end driver, which is actually Vasili's front end driver that was released a few years ago. This front end enhances the capabilities of the RTL-SDR as it exposes features like decimation and individual gain control. We note that the current version appears to have a bug preventing enhanced mode from starting, but we expect that it will be fixed again soon. Vasili's File Player has also been added, and this allows for easy playback of RTL-SDR IQ files.

The second feature added recently is an AM Co-Channel Canceller which is could be quite a big feature for medium wave (MW)/broadcast AM DXers. When DXing MW a problem is that you'll often encounter is two stations that are on or almost on the same frequency. This is either due to neighbouring countries not agreeing on frequencies, long range DX antennas picking up further than the intended broadcast range, or from malicious jamming as with the Chinese Firedrake. With a standard radio or demodulation algorithm such a situation makes either both stations impossible to listen to, or only the strongest station will be heard. However, the new AM Co-Channel Canceller plugin in SDR# uses clever DSP algorithms to allow one of those channels to be effectively removed, allowing you to listen to the other station clearly.

Over on the SWLing blog Guy Atkins has written up a comprehensive review and tutorial of the Co-Channel canceller plugin. We've also seen a few examples up on YouTube already, and the video posted below shows user "SDR-radio" in Japan experiencing a South Korean station blocking out a weak local Japanese station. Enabling the plugin allows the weaker station to be heard.

SDR# (SDRSharp): AM Co-Channel Canceller plugin

Shiva DX Cluster For SWL/BCL with SDR-Console V3

Thank you to Walter Panella (IU2MEH) for submitting information about his Shiva DX Cluster software which is designed to be used with SDR-Console V3. A DX Cluster is a type of distributed network of software that is used to to advertise that long-distance amateur radio DX stations are transmitting. Walter writes:

Shiva DX Cluster connects to a ham radio dx cluster and repeat the dx spot to shiva clients while adding spots based on list files.

It doesn't send to ham radio dx cluster any spot nor it can receive any spot.

It is intended to use with SDR Console for SWL/BCL ( see screenshots folder ) so they are able to see broadcasting stations, for example, based on scheduling day and time.

Ham radio dx cluster spots are repeated to shiva clients immediately, broadcasting stations and other lists are sent to shiva clients every 10 minutes (default,configurable).

The software is available on Walter's GitHub.

Shiva DX Cluster running on SDR-Console V3
Shiva DX Cluster running on SDR-Console V3

A tutorial on using RDS Spy with the SDR# MPX Output Plugin

Over on YouTube user pe1etr has uploaded a tutorial video showing how to set up RDS Spy and SDR# for monitoring RDS. RDS stands for Radio Data System and is a sub carrier added to some FM broadcast signals which carries information such as the station name, the song/programme playing and other data. Although SDR# decodes RDS stations already, a more powerful RDS decoder and monitoring tool is RDS Spy. To get RDS Spy to work with SDR# you need to use a special plugin called MPX Output, which allows SDR# to output audio that includes the RDS subcarrier, which can then be piped via a virtual audio cable to RDS Spy.

Pe1etr’s video shows how to install the MPX Output plugin, how to set it up with virtual audio cable and how to use it with RDS Spy.

Tutorial: Using RDS Spy with the SDR# mpx output plug-in

Comparison Between Portable Shortwave Radios and the RTL-SDR

YouTube user mutezone has uploaded a video showing a comparison between several portable shortwave radios and the RTL-SDR. His results show that the portable radios performed better than the RTL-SDR dongle at shortwave-dxing, however we are unsure of what method he used (direct sampling or upconverter) to get access to the shortwave bands on the RTL-SDR.

Shortwave Performance test: Portable Radios vs RTL-SDR