Tagged: ham radio

Setting up a Dual RX System with an SDR and Ham Radio Rig via an SDRSwitch

There are two common options when using an SDR together with a ham radio rig. You can either create an IF tap within your ham radio and connect the SDR to that, or connect the SDR directly to the antenna via a switch that switches the SDR out when transmitting.

Over on YouTube, Ham Radio DX has uploaded a video discussing the latter option and revealing its advantages. In the video, he mentions results by HB9VQQ that show that connecting an Airspy HF+ directly to an antenna via an SDR switch from SDRSwitch.com results in 60% more spots on WSPR, compared to using an IF tap from an FT450D ham radio rig.

He goes on to explain and demonstrate his setup and the recommended switch that he is using, which is the SDRSwitch by N2EME, available at SDRSwitch.com. He notes that this switch is recommended due to its very low insertion loss and high isolation specifications and compares it against an MFJ switch, which has some rather terrible specifications.

Add a SDR Receiver to ANY Ham Radio Rig!

HOPE XV Conference 2024: Ham Radio for Hackers Talk Video

Back in July 2024 we posted about Dan's (KB6NU) talk at the HOPE (Hackers of Planet Earth) conference about how Ham radio can be for hackers, and how hackers are the future of ham radio. Back then only the slides were available.

The video of the talk has recently been uploaded to YouTube, and is embedded below. The talk emphasizes how ham radio is not only about the traditional thought of making contacts, which is probably in most people's heads, but also about hacking radios, antennas, microcontrollers, satellites, pico balloons, digital communications, GNU Radio, and more. Dan mentions his goal is to promote ham radio to the much younger hacker crowd, where he believes it is underrepresented.

HOPE XV (2024): Ham Radio for Hackers

Ham Radio for Hackers

Over on Hackaday we've seen a post about Dan's (KB6NU) talk at the HOPE (Hackers of Planet Earth) conference about how Ham radio can be for hackers, and how hackers are the future of ham radio. Hackers in this context mean people who enjoy experimenting with electronics, building stuff, and understanding how things work.

Dan's slides have been uploaded on his blog. The slides emphasize how ham radio is not only about the traditional thought of making contacts which is probably in most people's heads, but also about hacking radios, antennas, microcontrollers, satellites, pico balloons, digital communications, GNU Radio and more. Dan mentions his goal is to promote ham radio to the much younger hacker crowd, where he believes it is underrepresented.

Ham radio for hackers
Ham radio for hackers

Video on Receiving HF Signals with the RTL-SDR Blog V3

Over on YouTube TheSmokinApe has uploaded a video showing how to use the direct sampling mode on RTL-SDR Blog V3 devices to receive HF transmissions, such as the ham bands, short wave and AM broadcast. In the video he shows how to activate direct sampling mode in SDR#, and then goes on to show reception of a few HF signals.

We note that an appropriate HF capable antenna is required to receive HF signals. The multipurpose dipole kits we sell are for VHF/UHF reception only. A simple and low cost HF antenna could just be a long wire running through your house.

HF Ham Radio with RTL-SDR Made EASY!

New HAM FM and ADS-B Radar Android Apps

Thank you to James Mainwaring for submitting news about the release of his two new RTL-SDR compatible Android Apps "Ham FM Radio (RTL-SDR)" and "ADS-B Radar (RTL-SDR)". 

The Ham FM Radio app allows the user to quickly tune and listen in to the 144-148, 150-174 and 420-450 MHz ham radio communications via presets. For the second ADS-B app, James notes that it's an early release for feedback. It allows the user to receive ADS-B data and plot it on a radar like display.

We note that we've previously posted about James' other apps for FM Radio and airband listening.

The Ham RF and ADS-B Radar Apps by James Mainwaring

Coronavirus: Hamvention Cancelled & Other Updates

Hamvention, the largest yearly amateur radio event has been cancelled this year due to concerns over the spread of the Coronavirus (COVID-19). It was due to be held during May 15 - May 18, 2020. Chairman Jack Gerbs writes:

The Hamvention Executive Committee has been monitoring the COVID19 pandemic. We have worked very closely with our local and state health Departments.

It is with a very heavy heart the Hamvention Executive Committee has decided to cancel Hamvention for this year.
This decision is extremely difficult for us but with around two months until the Great Gathering we felt this action necessary.
More specific details regarding the closure will soon be posted here.

Thank you for your understanding in this time of International Crisis.

Jack Gerbs
General Chairman HV2020
[email protected]

According to the ARRL cancelled events tracker, a number of other amateur radio events across the USA have also been cancelled, and we're seeing similar reports for most other countries too. At this stage we expect that most events will be cancelled over the next few months.

RTL-SDR Blog V3 Stock & Shipments

Due to manufacturing delays and slowdowns related to the Coronavirus our multipurpose dipole antenna set, and set including antenna and dongle is currently out of stock on our international webstore. We expect to be able to restock by the end of the month. There remains sufficient stock of the dongle itself. Our wideband LNA will also be back in stock next month.

Amazon USA is still stocked with all products, however there may be a short out of stock period within 1-2 weeks as we await for the arrival of replenishing stock in the USA.

In regards to international shipments please expect that there could be delays. At the moment we are seeing most mail still getting through in a timely manner, however this could change over the coming weeks as more travel restrictions come into play.

It is expected that other radio related products could also soon be out of stock, or delayed due to the situation.

Other Coronavirus Posts

N0SSC has provided a good post outlining the risks to the amateur radio population and why amateur radio event cancellations are a good idea. 

SolderSmoke, a popular podcast about radio homebrewers has put out a special Coronavirus crisis podcast.

We thought it would be nice to put out a special edition of the podcast to help listeners keep up their morale during this difficult time. So we’ll do our regular kind of show, but we’ll try to emphasize things you can do to stay busy and keep up morale while stuck at home.

Over on The SWLing Blog Thomas has put out a post about social distancing and how to keep occupied without leaving the house, and another post about how shortwave broadcasters are now adding regular Coronavirus information and news to their broadcasts.

Building a Transmit/Receive Relay System for a “Boat Anchor” Transmitter and SDRplay

Over on YouTube user ElPaso TubeAmps has uploaded a video showing his transit/receiver relay system that allows a "boat anchor" (old radio) ham radio transmitter and SDRplay SDR receiver to coexist. In order to protect the SDRplay's front end from being destroyed by a ham radio transmitting on the same antenna, a relay should be used to ground the SDRplay during a ham radio transmission. He writes:

How to build a small chassis and relay system to switch the antenna from the SDR input to ground and open the speaker connection from the PC to the speakers during transmit. I use "boat anchor", i.e. separate VFO for transmitter and receiver equipment and this video is about that type of connection and is not for transceivers.

SDRPlay, RTL-SDR, Transmit-Receive , PC Speaker, T/R Switch

Using a Raspberry Pi 3 and RTL-SDR as a 40m FT8/JT65/JT9 Monitor

Over on YouTube user radio innovation has uploaded a brief screen capture showing his Raspberry Pi 3 and RTL-SDR dongle being used as an always-on monitor for low transmit power based signals such as FT8, JT65 and JT9. These signals are transmitted by ham radio enthusiasts for the purpose of making contacts, and determining propagation conditions. This is a good application for an RTL-SDR and Raspberry Pi 3 as it enables cheap monitoring of these signals without the need to tie up a full sized ham radio.

To do this "radio innovation" runs Linrad on the Raspberry Pi, which is a program like GQRX that interfaces with the RTL-SDR dongle. Then the WSJTx software is used to decode the signals. He writes:

Remote Desktop screencapture of my Raspberry Pi3 monitor receiver on 40m amateurradio band with WSJTx and decoding FT8,JT65 and JT9. Receiver hardware is RTL-SDR(tcxo) + simple converter and homemade bandpass filter.

SDR software is LINRAD by SM5BSZ.

RasperryPi3 OS is Ubuntu Mate 16.04.

Update: We now have a tutorial on creating a similar set up available on a new post.