Many thanks to SWLing Post contributor, Dan Srebnick (K2DLS), who notes that Whistler currently has a selection of refurbished scanners on sale with a manufacturer’s warranty including the new TRX-1 handheld:
Moments ago, I posted a press release from the UK-based software-defined radio manufacturer, SDRplay, announcing their latest product: the RSPduo: a 14-bit Dual Tuner SDR.
I should start with the disclaimer that, not only was I sent an RSPduo to review and evaluate, but SDRplay has been a supporter of the SWLing Post for a few years now. You’ve no doubt seen their ads in the upper right corner of our site. After I reviewed their first SDR (the RSP1) I discovered that SDRplay––all of their staff and supporters––welcome constructive criticism and even invite frank discussions. They’re a company with integrity. No doubt, this is why I agreed to alpha- and beta-test their SDRs. Fortunately, I’ve not been disappointed.
As a company, moreover, SDRplay breaks the mold––and in very good ways:
SDRplay is a small company that employs actual radio enthusiasts. Their designs and software cater to DXers, SWLs, hams, scanner enthusiasts, amateur astronomers, experimenters, and makers, among others.
SDRplay designs and builds their products in the United Kingdom. No doubt they could increase their profit margin by using manufacturing centers in China, but they choose not to do so, to the benefit of their products.
The quality of the company’s products is, at least to date, excellent.
SDRplay’s product pricing is nonetheless quite affordable
That last item, in particular, is a head-scratcher. Considering these facts, how does SDRplay still manage to keep their pricing so competitive? I only wish I knew. When the company released the RSP1A last year, I had already spent a few months with alpha and beta units, mulling over their respective merits (and there were many). So I was simply gobsmacked when they announced that the price would be just $99 US. I rather figured the company was leaving money on the table, although I was pleased to announce this price to my readers here.
Fast-forward to two weeks ago: I received the new RSPduo to review. And the price this time? $279 US. While this is currently the priciest product in the SDRplay line, let’s go over what makes this SDR special…and why I still think SDRplay may be leaving money on the table.
Introducing the SDRplay RSPduo
The RSPduo is unlike any other SDR in the SDRplay product line, and, indeed, unlike most of the budget SDRs currently on the market.
As “duo” implies, this RSP features dual independent tuners, both piped through a single high-speed USB 2.0 interface. With the RSPduo, you can explore two completely separate 2 MHz bands of spectrum anywhere between 1kHz and 2GHz.
SDRplay lays out several use-scenarios in their press release:
The ability to simultaneously receive on two totally independent 2 MHz spectrum windows anywhere between 1 kHz and 2 GHz
Simultaneous processing from 2 antennas enables direction-finding, diversity, and noise-reduction applications
Ideal for cross band full-duplex reception, e.g. HF + VHF, or VHF + UHF
Simultaneous Dump1090 and VHF ATC reception
Simultaneous monitoring and recording of 2 ISM bands
Use SDRuno to seamlessly control and manage the dual tuner in a single environment.
Externally, the RSPduo bears a strong resemblance to the RSP2pro. Internally, however, it’s quite different.
Besides featuring a second independently controlled tuner, the RSPduo also sports 14 bit ADCs and a completely re-designed RF front end, which enhances receiver selectivity and improves dynamic range.
In short, the RSPduo is like having two SDRs in one.
I received the RSPduo during a very busy time of the year: the build up to the Hamvention in Xenia, OH.
One of the first things I noticed about the RSPduo is its weight. When I picked up the package from SDRplay, I could tell it weighed at least twice that of the RSP1A. One reason for the extra heft is that the RSPduo, like the RSP2 Pro, has a metal enclosure. I’m willing to bet the RSPduo also has more shielding––adding even a little extra weight.
I’ve had the RSPduo on the air for more than a week now, and have checked out all of its major functions and begun to learn the nuances of navigating the dual receivers in the latest version of SDRuno.
SDRplay will, I feel sure, post a primer video on using the various dual tuner functions in the coming weeks.
Installation of the software, even in pre-production, was totally a “plug-and-play” experience. Simply install the SDRuno software package with the RSPduo disconnected from the USB port. Plug in the RSPduo, and wait for the USB driver to load, then open SDRuno. That’s it. You’re on the air!
As I’ve indicated, the RSPduo is really like having two RSP1As in a single RSP2 Pro package. One of these dual receivers––the master––can utilize either a standard 50 ohm SMA antenna port, or a Hi-Z port. The second receiver uses one 50 ohm SMA antenna port just like the RSP1A.
I much prefer using the Hi-Z port for everything longwave and mediumwave. I did hook up both antenna ports on the master receiver, however, and switched back and forth between the two. At least in my antenna setup, I feel like the Hi-Z option lends itself to improved sensitivity on these bands. It’s not a dramatic difference––indeed, looking at the spectrum display one barely notices the difference––but my ears told me the noise floor was lower and signal strength slightly better with the Hi-Z port. Above 2 MHz, the Hi-Z port is not prefered since it lacks the same level of RF pre-selection as the 50 ohm ports provide.
Unlike the Hi-Z port with the RSP2, the RSPduo treats the Hi-Z port more like an auxiliary antenna port. When I employed the Hi-Z port in the HF bands, I did notice small spurious noises, but this might have been due to my antenna port configuration here in the shack (my Hi-Z connector is simply attached to the shield and center conductor of my coax).
Again, however, for anything above 2 MHz, SDRplay suggests using the 50 ohm ports.
How to set up dual receivers on one screen/monitor
Listening to the FM broadcast band on the main receiver and Voice of Greece shortwave on the second receiver.
One of the first things I was eager to do was to run the dual receiver functionality on one monitor. Although SDRplay makes this a pretty simple process in the latest version of SDRuno, I still stumbled a bit as I learned to navigate the controls.
Here’s a quick primer to get both receivers on the air on one monitor/screen:
First, open SDRuno in “single receiver mode” (the typical SDRuno default).
Next, click on the “RSPduo mode” button and select one of the modes. In this case, I’m not running the ADS-B application, so I’ll choose “DUAL (NORMAL)”.
Now, to format the “Master” receiver windows so they only use the top half of the monitor, click on the OPT button.
Select “Auto Layouts” and “RSPduo Master.”
If you’ve followed these steps with me, your screen should look something like this:
Now you’ll want to start the second receiver. Do this by opening the SDRuno application again (as if you were opening SDRuno for the first time). Make sure you’ve selected your RSPduo if you have more than one RSP connected.
The new instance of SDRuno will fill the entire screen by default, so you’ll need to format it to occupy the lower half of the screen.
Simply click on the OPT button again, select “Auto Layouts,” and “RSPduo Slave.”
Your full screen should now look something like this:
Now you can start using both receivers, but you’ll have to always start the “Master” receiver first. In fact, the “Master” receiver must always be active in order to operate the “Slave” receiver. You can always close the “Slave” receiver without affecting the “Master” receiver; however, if you close the “Master” receiver, you will effectively close both receivers.
Again, I fully expect SDRplay will soon produce a demonstration video showing how you can navigate SDRuno’s new dual-receiver functionality.
As I’ve mentioned in most previous SDR reviews, I do like to take a considerable amount of time to set up SDR comparisons.
Herein lies the difficulty of reviewing an SDR’s performance. Because the user has so much power to control variables and thus shape the receiver’s function, it’s actually quite hard to make an “apples-to-apples” comparison––insuring that all important filters, gain controls, DSP, etc., are as close to identical as possible.
One tool that helps me do this is SDR Console, since it can control a number of SDRs and receiver parameters can be set up identically. Unfortunately, the RSPduo is so new, SDR Console doesn’t yet support it.
I did use SDRuno to compare the RSPduo with the RSP1A. Fortunately, I could actually run two separate instances of SDRuno simultaneously (and on different monitors, in my case). Both were hooked up to the same antenna via my ELAD ASA15 antenna splitter amplifier.
The RSPduo’s improved dynamic range gives it an advantage in terms of noise floor, sensitivity, and selectivity.
The improved performance is not dramatic––but I understand it might be especially detectable to those who want a receiver with a more robust front end.
In fact, the RSPduo’s 50 ohm coaxial ports have quite an array of automatically configured front end filters:
2 MHz Band Pass
And an array of notch filters
FM Notch Filter:
>30dB 77 – 115MHz
>50dB 85 – 107MHz
>3dB 144 – 148MHz
MW Notch Filter:
>15dB 400 – 1650kHz
>30dB 500 – 1530kHz
>40dB 540 – 1490kHz
DAB Notch Filter:
>20dB 155 – 235MHz
>30dB 160 – 230MHz
The thing is, I live in an RF quiet area, so I can’t fully take advantage of the SDRuno’s more robust front end.
In head-to-head comparisons with the RSP1A, the RSPduo’s performance edge is discernible. Again, I suspect it would be a bit more obvious if I lived in an urban setting with blowtorch stations in the neighborhood. Using the Hi-Z antenna port in the mediumwave portions of the band, the RSPduo has a performance edge over the RSP1A, as well.
Should you grab the RSPduo?
The new SDRplay RSPduo
Anytime a new product hits the market, I ask myself if this is the sort of product that would tempt me to reach for my hard-earned cash.
The short answer? Absolutely! Take my money, please! There is no other sub-$300 SDR on the market currently that has the dual tuner functionality of the RSPduo. Thing is, I’ve only had the RSPdup a couple of weeks–there’s so much yet I want to explore here–especially diversity reception!
But what if you already have an SDRplay SDR? Afterall, the RSP1A was only released a few months ago, and the RSP2 series only a year before that.
Here’s my opinion: If you’re an RSP1A or RSP2 owner who is pleased with this SDR’s performance, I wouldn’t necessarily urge you to purchase the RSPduo simply for the modestly enhanced performance characteristics. SDRplay hasn’t retired the RSP2 and RSP1A designs because each model still holds its own, has a purpose, and obviously enjoys a healthy market.
The RSP1A is the affordable yet high performance entry model in the SDRplay product line. It’s really the best value in the radio world, in my humble opinion, at just $99 US. Som enjoy.
The RSP2 and RSP2pro provide excellent performance, three software-selectable antenna inputs, and clocking features, all of which lend it to amateur radio, industrial, scientific, and educational applications; it is a sweet SDR for $169 or $199 (Pro version). I know of no other SDRs with this set of features at this price point. If I liked the characteristics of the RSPduo, but didn’t really need a dual receiver for my application, I’d probably reach for the RSP2 Pro.
But if you have the original RSP, and like SDRuno and the SDRplay community, then I would certainly consider this an opportunity to upgrade. For $279, you’re getting a dual receiver SDR with excellent performance characteristics that will easily surpass the original RSP––considering that you’re essentially getting two very good SDRs in one.
And if you’re all over the spectrum (aren’t we all a bit––quite literally?) in terms of usage, the RSPduo is a fascinating machine for running, say, an ADS-B receiver while independently using the same SDR box to monitor other parts of the spectrum. Or one can listen for FM DX on one receiver while trying to snag elusive LW DX on the other.
Better yet, the RSPduo only uses one USB port––an important factor if you’re using a laptop or tablet. Of course, having two receivers on two different antennas, while sharing one data port, means syncing them for diversity reception is especially effective. This alone will sway many SDR experimenters in favor of this rig.
I have yet to compare the RSPduo with the brilliant little AirSpy HF+. The AirSpy HF+ is not a wideband receiver like the SDRplay RSP series; it only covers 9 kHz to 31 MHz and 60 to 260 MHz. But if your primary concern is HF performance, the HF+ and its excellent dynamic range will impress you, if you’re anything like me. It’s also a bargain at $199––very hard to beat!
The RSPduo is a good value, in my opinion––and an inexpensive upgrade to a proper dual receiver SDR––so if that’s the sort of thing you’d like to add to your shack, go ahead and bite the bullet!
In fact, I suspect SDRplay will quickly sell out of all of the units they bring to the 2018 Hamvention (SDRplay: pack some extras!). I’m happy to see the company continue to push the price and performance envelope to such exceptional ends. I’m also looking forward to the many applications SDRplay customers (and our readers) find for the RSPduo.
Stay tuned! I plan to post more comparisons in the future.
And if you acquire an RSPduo and find some new and fun applications for it, please share!
SDRplay announces the RSPduo – A 14-bit Dual Tuner SDR
Today at the Dayton Hamvention, SDRplay Limited is announcing the launch of a new Software Defined Radio product – the RSPduo.
The RSPduo is a radical new addition to the RSP line of SDR receivers from SDRplay. Architecturally, it is different from any previous RSP in that it features dual independent tuners, both piped through a single high-speed USB 2.0 interface.
The SDRplay RSPduo is a dual-tuner wideband full featured 14-bit SDR which covers the entire RF spectrum from 1kHz to 2GHz giving 10MHz of spectrum visibility. Initially using Windows based ‘SDRuno’ supplied by SDRplay, you can simultaneously monitor two completely separate 2MHz bands of spectrum anywhere between 1kHz and 2GHz.
Superficially the RSPduo looks identical to the highly popular RSP2pro and will be able to operate in a very similar way.
However, it also allows a completely new and exciting set of usage scenarios such as:
Simultaneous monitoring of two widely spaced bands – e.g. 40m (HF) and 2m (VHF)
Mixing and matching applications simultaneously – e.g. ADS-B and ATC scanning
Phase and time coherent demodulation of two receivers
Scenario 3 is very difficult to achieve with two separate USB devices because of the uncertainty of USB latency. The RSPduo overcomes this limitation because all traffic goes through a single USB interface, thus enabling the possibility of the development of various types of diversity demodulation such as: spatial, frequency and polarisation which can bring
huge benefits in terms of improved performance.
Jon Hudson, Marketing Director at SDRplay commented:
“As well as adding a second independently controlled tuner, which in itself, offers a whole new set of exciting usage possibilities, the SDRduo features 14bit ADCs and a completely re-designed RF front end. These changes provide better RF selectivity and even more dynamic range, offering outstanding performance under extremely challenging reception conditions. The combination of performance and features makes the RSPduo our highest spec RSP yet and sets a new benchmark in the sub $300 SDR market”
Due to its exceptional combination of performance and price, the RSP family of receivers have become very popular and the RSPduo provides the next level of functionality for both amateur radio enthusiasts as well as the scientific, educational and industrial SDR community.
As well as being demonstrated at Hamvention, the RSPduo is available direct from SDRplay or via SDRplay’s network of channel partners and resellers
The RSPduo is expected to retail at approximately $279 USD (excluding taxes) or £199 GBP (excluding taxes).
About SDRplay: SDRplay limited is a UK company and consists of a small group of engineers with strong connections to the UK Wireless semiconductor industry. SDRplay announced its first product, the RSP1 in August 2014
Many thanks to SWLing Post contributor, Mario Filippi (N2HUN), for sharing the following guest post:
TYT Frequency Counter/Tone Meter Review
by Mario Filippi (N2HUN) All photos courtesy of author
Most hobbyists own some type of transceiver whether it is a handheld, mobile, or base station. Some examples are amateur radio HF/VHF/UHF transceivers, Citizen’s Band radios, FRS (Family Radio Service) and GMRS (General Mobile Radio Service) handhelds.
A useful tool for the shack or the field is a frequency counter/tone meter since it can measure frequencies and analog/digital tones from transmitters/transceivers. At times ascertaining that a UUT (Unit Under Test) such as a 2 meter handheld is transmitting accurately may be indicated due to problems communicating with other stations. In addition, if the UUT transmits a sub-audible tone (either analog or digital) to access a repeater, a frequency counter/tone meter can detect the presence and verify accuracy of the CTCSS/digital tone.
Author’s TYT SF-401Plus, includes instructions, antenna, rechargeable battery and charger/cable. Covers 27 MHz – 3 GHz
Frequency/tone meters can be purchased for less than twenty US dollars but normally do not include a rechargeable battery and BNC connector for attaching an external antenna. Having had experience with these types, the time finally came for an upgrade.
After shopping around a decision was made to purchase the Tytera TYT SF-401 Plus. This model includes an instruction sheet, antenna, internal rechargeable battery, USB charger and cable. It represents a significant improvement over my previous, inexpensive meter, as the TYT has a BNC connector to attach a larger antenna and has four control buttons on the front panel. It also has, via a system menu, options to adjust the frequency/tone offset, dimmer levels, three or four decimal display and auto power off. All these valuable features warrant a higher cost, which was about $50, but well worth it. This price fits the budget of most hobbyists. However, higher end frequency/tone meters are available and cost several hundred dollars for those requiring that level of quality.
Out of the box the TYT SF-401 Plus, when checked against an IFR FM/AM-500A communications service monitor, was right on the money as far as accuracy. Note that the IFR-500A was calibrated against a high precision internal 10 MHz crystal in an “oven” and this is my gold standard reference for frequency accuracy in my shack.
TYT accuracy checked against an IFR FM/AM-500A communications service monitor transmitting a 146.52 MHz/131.8 Hz tone. Note frequency readout to four decimal places.
Now, it was time to check typical radios around the shack using the TYT. The first radio tested for frequency accuracy was a BTECH GMRS-V1 HT which I use to communicate with the home QTH while running errands around town. See photo for results. The BTECH and TYT agreed perfectly. Note that the TYT’s display includes a battery status indicator on top left and a timer use indicator, which resets every time the TYT is turned on. If you are going to measure digital signals (not included in this review) there is an option in the Setup Menu for that. With the BTECH handheld running 2 watts the TYT could detect its’ frequency at roughly four feet away.
Confirming BTECH transmit frequency against the TYT. Output is 2 watts. TYT multicolor display is super.
For VHF/UHF operating, especially when afield with other hams or groups such as CERT (Community Emergency Response Teams), problems can ensue if one does not have the correct frequency or tone programmed, so having the TYT in your shirt pocket to confirm these parameters when trouble occurs can be a quick way to get to the problem. See photo of an Icom IC-2300H 2 meter transceiver checked against the TYT for proper offset and tone. The Icom was putting out 65 watts and a repeater with an offset of -1.3 MHz and 88.5 Hz tone was checked.
TYT confirming unusual offset (-1.3 MHz) and tone for a repeater. Icom IC-2300H was at high (65W) setting and connected to an outdoor discone antenna.
According to the instructions included with the TYT SF-401 Plus, the operating range is from 27 MHz – 3000 MHz with a note stating “27 MHz – 100 MHz it can not be guaranteed and the corresponding normal emission appliance” which I interpret as accuracy is not guaranteed in this frequency range. Well, I checked the TYT against the IFR FM/AM-500A service monitor transmitting an AM signal on CB Channel 19, 27.185 MHz, and the TYT measured it exactly. One other important note is that according to the instructions, the tone decoder operates in the 136 MHz – 174 MHz and 400 MHz – 520 MHz frequency range. So that may limit its use in certain areas of the spectrum. One other item if interest is that the TYT has a 10 dB attenuator when dealing with high power signals.
All in all, I’m very happy with this purchase, and find the TYT SF-401 Plus useful for “first pass” troubleshooting and helpful when aligning older rigs which due to age are off frequency /tone. It definitely has a use in this shack.
Wow–what a bargain tool for the radio shack! Thank you for sharing your review, Mario. Once again, however, you have tempted me with a purchase! I remember when frequency counters would set you back a couple hundred bucks–it’s insane to think that you can grab one for $40-50 US shipped.
SF-401 Plus Retailers:
Note that the TYT SF 401 Plus is also marketed as the Surecom SF401 Plus:
On April 18, consider setting your scanner or handheld VHF radio to 145.80 MHz around 15:57 UTC; you may be able to hear the downlink from the International Space Station. The Amateur Radio on the International Space Station (ARISS) contact will be between between NA1SS (on the ISS) and KD2IFR at a school in Central Islip, NY.
As long as you’re within the ISS’ signal footprint (which is rather large) you should be able to easily hear NA1SS’ side of the conversation. I’ve listened to the downlink in the past using an Icom ID-51a and the super compact Yaesu VX-3R:
The frequency of the downlink will be 145.80 MHz. As the ISS climbs above your horizon, because of doppler-shift, listen on 145.805, then move to 145.80 as the ISS approaches zenith and finally move to 145.795 MHz as the ISS drops toward the other horizon. As we’ve mentioned in past posts, you’ll know when to switch frequency when the audio gets bad.
Upcoming ARISS contact with Central Islip Union Free School District, Central Islip, NY
An International Space Station school contact has been planned with participants at Central Islip Union Free School District, Central Islip, NY on 18 April.
The event is scheduled to begin at approximately 15:57 UTC. The duration of the contact is approximately 9 minutes and 30 seconds.
The contact will be direct between NA1SS and KD2IFR. The contact should be audible over the state of New York and adjacent areas. Interested parties are invited to listen in on the 145.80 MHz downlink. The contact is expected to be conducted in English.
Welcome to the Central Islip Union Free School District – Home of the Musketeers and a proud Suffolk County, New York school system, where approximately 8,000 students in grades Pre-Kindergarten through 12 receive their formal education. Our School District’s motto is Children Our Future ~ Diversity Our Strength. The Central Islip Union Free School District is comprised of eight schools: one district-wide early childhood center, four elementary schools, two middle schools and a high school.
The Hamlet of Central Islip is a vibrant, culturally-diverse community. A suburban community with urban demographics. We are a positive and progressive school district whose teachers are dedicated to helping students achieve their maximum potential and to develop academically and socially. Our district offers an array of afterschool activities including sports, music, theatre arts and much more.
Participants will ask as many of the following questions as time allows:
1. What are the challenges of spending so many months constantly around the same people?
2. What is the best way to describe the feeling of zero gravity?
3. Have you experienced anything unexpected while in space that could not be explained?
4. Have you experienced any significant changes, either physically or emotionally, since being in space?
5. What type of robots do you use on the ISS and how are they helpful?
6. What is your advice for young people who want to become involved in programs at NASA?
7. What is the biggest challenge about being on a long duration space mission?
8. How does digestion in microgravity compare to digestion on Earth?
9. Have you experienced anything in space that has made you change your perspective on life?
10. Are there any plants aboard the ISS and if so, what’s different about how they meet their daily requirements?
11. What are the long term effects of reduced leg muscle use in long duration space travel?
12. Is your circadian rhythm affected by multiple sunrises and sunsets each 24 hour period, perhaps making it difficult to sleep for long periods of time?
13. Can you describe the types of training that prepared you for this mission?
14. Can you catch a cold on the Space Station?
15. Do the properties of light appear to be different in space?
16. Are there differences in how your body responds to physical exertion while in microgravity?
17. Would it be possible to transmit a mechanical wave on a rope onboard the space station or outside the station?
18. What are the hardest tasks to perform in space that are routine on Earth?
19. Could you blow a bigger than normal gum bubble in space?
20. Are there precautions that you take BEFORE going into space that can help to prevent bone weakness when you return?
PLEASE CHECK THE FOLLOWING FOR MORE INFORMATION ON ARISS UPDATES:
Visit ARISS on Facebook. We can be found at Amateur Radio on the International Space Station (ARISS).
To receive our Twitter updates, follow @ARISS_status
Next planned event(s):
1. King’s High School, Warwick, UK, direct via GB4KHS
The ISS callsign is presently scheduled to be OR4ISS
The scheduled astronaut is Ricky Arnold KE5DAU
Contact is a go for: Thu 2018-04-19 12:05 UTC
2. Russian school TBD
The ISS callsign is presently scheduled to be RS?ISS
The scheduled astronaut is Alexander Skvortsov
Contact is a go for Tue 2018-04-24 11:05 UTC
3. Russian school TBD
The ISS callsign is presently scheduled to be RS?ISS
The scheduled astronaut is Alexander Skvortsov
Contact is a go for 2018-04-25 08:35 UTC
Amateur Radio on the International Space Station (ARISS) is a cooperative venture of international amateur radio societies and the space agencies that support the International Space Station (ISS). In the United States, sponsors are the Radio Amateur Satellite Corporation (AMSAT), the American Radio Relay League (ARRL), the Center for the Advancement of Science in Space (CASIS) and National Aeronautics and Space Administration (NASA).
The primary goal of ARISS is to promote exploration of science, technology, engineering, and mathematics (STEM) topics by organizing scheduled contacts via amateur radio between crew members aboard the ISS and students in classrooms or informal education venues. With the help of experienced amateur radio volunteers, ISS crews speak directly with large audiences in a variety of public forums. Before and during these radio contacts, students, teachers, parents, and communities learn about space, space technologies, and amateur radio.