Shortwave listening and everything radio including reviews, broadcasting, ham radio, field operation, DXing, maker kits, travel, emergency gear, events, and more
We’re all used to turning a couple of knobs and pressing a few buttons to operate a radio, but have you ever played with glasses of water to change a radio channel? Probably not. Designers Tore Knudsen, Simone Okholm Hansen, and Victor Permild recently launched their art project ‘Pour Reception’. And it’s beyond anything you can imagine. Pour Reception consists of two internal speakers, an AUX input, a handy guide and two glasses that must be placed on the body of the radio. And no the glasses aren’t just to sip water from, though you could do that. The radio uses the two glasses filled with water as it’s interface!
[…]Pour water into the glasses, and the stereo starts! Transfer some water from one glass to another and you can change channels. Touch the glasses, and you can fine-tune the radio’s signal, eliminating distortion. Finally, pop a finger into the water to control the volume or to bring the radio to a halt!
This might seem like a scenario from an alternate universe, but the tech behind it is pretty common. Objects emit micro amounts of electricity, and touch tends to disrupt this and convert it into a signal. By using Tact library by NANDstudio (an open-source Arduino shield that turns any object into a touch and proximity sensor), the designers converted the radio platform, glasses, and water into different layers of a capacitive interface, allowing them to conduct minute amounts of electricity and transforming them into sensors. Utilizing a Wekinator (an interactive machine learning tool), various gestures such as touching the glass or dipping a finger into the water were mapped into commands for controlling the radio. The end result; a radio with glasses of water functioning as a “digital material interface”.[…]
Oh now that’s a fun way to combine radio and art! Obviously, this isn’t an RF radio–it either grabs streaming content or (more likely) uses pre-recorded content on an internal storage device. Still, I think it’s a creative little project and an ideal way to play with Arduino Tact library.
For over two weeks now, I’ve had an early production model of the RSPdx here in the shack operating on a beta version of the SDRuno application.
In the spirit of full disclosure, SDRplay is a long-time supporter of the SWLing Post and I have alpha- and beta-tested a number of their products in the past. This early production RSPdx was sent to me at no cost for a frank evaluation, and that’s exactly what I’ll offer here. To be clear, while I am using beta software, this is not a beta SDR, but one from a first limited production run.
And thus far, I must say, I’m impressed with the RSPdx.
Upgrades
The RSPdx has been introduced as a replacement for the RSP2 and the RSP2pro receivers. It has been updated and upgraded, with a completely new front-end design.
Here are the highlighted improvements and changes:
Performance below 30 MHz has been enhanced when compared to the RSP2/RSP2pro.
Performance below 2 MHz has been substantially upgraded. Through the use of the new HDR mode, both dynamic range and selectivity have been considerably improved.
There is now a BNC antenna connector on antenna C position instead of a HiZ port. Both A and B antenna ports are SMA like other RSP models.
Let’s face it: those of us interested in low-cost SDRs are spoiled for choice these days. The market is chock-full of sub-$200 SDRs, especially if you include all of the various RTL-SDR-based SDRs and knock-off brands/models one can find on eBay.
Personally, I invest in companies that support radio enthusiasts for the long haul…those that do their own designs, innovations, and production. SDRplay is one of those companies.
SDRplay’s market niche has been providing customers with affordable, high-performance wideband receivers that cover an impressive 1 kHz to 2 GHz.
Wideband coverage can come at a cost. Unless you pay big money for a commercial-grade wideband receiver, you’re going to find there’s a performance compromise somewhere across the spectrum. On the RSP2 series, those compromises would have been most apparent on frequencies below 30 MHz.
That’s not to say HF, MW, and LW performance was poor on the RSP2 series–indeed, it was quite impressive and well-balanced; it just didn’t stack up to the likes of the similarly-priced AirSpy HF+ and HF+ Discovery, in my humble opinion. Both little Airspy SDRs have wooed DXers with their impressive dynamic range and overall ability to work weak signals in the HF portion of the spectrum.
Neither of the AirSpy HF+ models are wideband receivers, but still offer a generous range: 9 kHz to 31 MHz and from 60 to 260 MHz––about 11.5% of the frequency coverage of RSP models. (Note that the Airspy R2 and Mini do cover 24 – 1700 MHz.) For shortwave radio listeners that also want to venture into the UHF and SHF regions, a wideband SDR is still required.
It’s obvious SDRplay’s goal is to make the wideband RSPdx into a choice receiver for HF and, especially, for MW/LW DXers. But have they succeeded? Let’s dive in…
Performance
As I say in most of my SDR reviews: doing comparisons with receivers that have so many features and adjustments is never easy. In other words, we want an apples-to-apples comparison, but it can be difficult to achieve, especially with new products.
The RSPdx, Excalibur, and HF+ Discovery all used the same antenna in my tests––a large, horizontal delta loop antenna, via my ELAD ASA15 amplified antenna splitter. I’ve used this antenna splitter for years and can vouch for its equitable, lab-grade distribution of signal.
The RSPdx is not in full production at time of posting, thus application options are limited. Typically, I’d load comparison SDRs in SDR Console or HDSDR and test them with identical settings as well. At present, the RSPdx is only compatible with a beta version of SDRplay’s own application, SDRuno (which will come out of beta rior to the first major production run). The benefit of using SDRuno is that you unlock the full potential of the RSPdx, plus signal and noise numbers are incredibly accurate.
For each SDR in this comparison, I used their native/OEM application to give them the best possible performance.
I also matched filter settings and made an effort to match AGC and volume settings as closely as I could.
Additionally, I resisted the temptation of comparing my RSP2 with the new RSPdx because I didn’t want to run two simultaneous instances of SDRuno on the same computer––especially considering one was in beta.
Is this comparison perfect? Probably not, but I did the best with the time I had available. I do intend to make further comparisons in the future.
Longwave performance
Via the RSPdx’s new “HDR” mode, both dynamic range and selectivity have been considerably improved with frequencies below 2 MHz. While I’ll fully admit that I’m not much of a longwave DXer, my very first listening session with the RSPdx started in this region of the spectrum.
In fact, the first evening I put the RSPdx on the air and confirmed that I was, indeed, in HDR mode, I noticed a small carrier via the spectrum display on 171 kHz. I clicked on it and quickly discovered it was Medi 1. The signal was faint, but I could clearly ID at least one song. This truly impressed me because I believe this was the first time I had logged Medi 1 on longwave from the shack.
I didn’t connect the Excalibur at that point to see if it could also receive the faint Medi 1 signal, but I imagine it could have. I’m pretty sure this would have been outside the reach of the RSP2, however.
I tried to explore more of the longwave band, but due to local RFI (I suspect an appliance in my home), most of the LW band was inundated with noise. With that said, I did grab three of my benchmark non-directional beacons.
Obviously, the RSPdx is a capable LW receiver. I would like to spend more time on this band once I’ve tracked down the source of my local RFI.
Mediumwave/AM performance
In the past two weeks, I’ve spent many hours with the RSPdx on mediumwave.
We’re heading into the winter months in the northern hemisphere, and that’s normally when my listening habits head south on the bands.
In short: I find the RSPdx to be quite sensitive and selective on the mediumwave bands while the HDR mode is engaged. A major improvement over its predecessor.
I primarily compared the RSPdx with my WinRadio Excalibur on mediumwave since I consider the Excalibur to be a benchmark MW receiver. And, as you’ll hear in the screencasts below, the RSPdx truly gives the Excalibur a run for its money:
Note that my horizontal delta loop antenna is omni-directional, hence the tug-of-war you hear between stations in the clips above.
In truth, I could have done more to stabilize the signal on both of these fine SDRs, but I wanted to keep the comparison as fair as possible.
You might have noticed that both were running AM sync mode. It seems the sync lock on the RSPdx may have also improved––though I would need to do a direct comparison with the RSP2 to know for sure––but in terms of stability, I still found that the WinRadio Excalibur was superior. Mind you, the Excalibur is a $900 – $1,000 receiver and has the strongest synchronous detector of any radio I’ve ever owned.
Shortwave/HF
SDRplay notes on the preliminary specifications sheet that the RSPdx has been “enhanced” when compared with the RSP2 series.
And, after having spent two weeks with the RSPdx on the shortwave bands, I would say this is a bit of an understatement. For although I haven’t compared the RSPdx directly with the RSP2 yet, I do feel HF performance is substantially better than its predecessor. Indeed, in my comparisons, I often found it gave the Excalibur some serious competition. Overall, the Excalibur had an edge on the RSPdx, but the gap has closed substantially. That’s saying something.
For the comparison videos below, I also included the excellent AirSpy HF+ Discovery.
As you can see and hear, the RSPdx is now in the league of some of the finest HF receivers in my arsenal.
But I’m curious to know what you think after listening to these comparisons. Please comment!
Notch Filters
For those of you living in areas with DAB/DAB+ broadcasters nearby, you’ll be happy to note that the RSPdx has a DAB filter to help mitigate any potential overloading.
Also, if you live near a blowtorch mediumwave station, you’ll be quite pleased with the MW notch filter. It’s so effective at filtering out the mediumwave band, my local blowtorch on 1010 kHz is barely visible on the spectrum once the notch filter is engaged. (Note: I should add that neither the DAB nor the mediumwave notch filter was engaged during any of my previous comparisons above.) Check out the screen shots below showing the mediumwave band before and after the MW notch filter is engaged:
Before:
After:
Summary
For those of you looking for a budget wideband SDR with solid performance below 30MHz, look no further.
For $199 US, you’re getting a quality UK-designed and manufactured SDR in a proper metal housing. The OEM application, SDRuno, is one of my favorite SDR applications and can fully take advantage of the RSPdx’s new HDR mode. No doubt, with a little more time, most third-party SDR applications will also support the RSPdx.
Frankly, I was expecting classy mediumwave and longwave performance as this was the most touted upgrade of the RSPdx. SDRplay certainly delivered.
In my experience, SDRplay doesn’t oversell their products. Their preliminary product sheet mentioned improved performance on HF, but their press release didn’t even mention the HF upgrades. And this is where I, in particular, noticed significant improvement. Perhaps this is because I am primarily an SWLer, thus spend a larger portion of my time in the HF region.
SDRplay products also have a mature, robust SDR application via SDRuno. Day to day, I tend to use Simon Brown’s SDR Console as my primary SDR application, since it’s compatible with so many of my SDRs and also offers some of the best recording functionality for those of us who do audio and spectrum archiving. Each time I beta test or review an SDRplay SDR, however, I’m more and more impressed with SDRuno. It’s evolved from being a rather cluttered application to one with a thoughtful, cohesive user interface that’s a joy to use––a product of true iterative agility.
Indeed, after having used SDRuno exclusively these past two weeks, I believe I would consider it as my primary SDR application…if only it had audio recording in addition to spectrum recording, and could run multiple instances with multiple SDRs. Again, given a little time, I wouldn’t be surprised if some of this functionality is eventually integrated.
Questions?
Since many SWLing Post readers already own an SDR, I’m sure some of you will have questions. Let’s address a few of those right now.
Question: “I have an RSP2/RSP2pro. Should I upgrade to the RSPdx?”
My recommendation: If you are a shortwave, mediumwave, or longwave DXer, I would indeed recommend upgrading to the RSPdx. If you primarily use your RSP2 series SDR on frequencies above 30 MHz and only occasionally venture below for casual listening, then I’d keep the RSP2.
Question: “I have an RSP1a. Should I upgrade to the RSPdx?”
My recommendation: If you’ve been enjoying your RSP1a and would like to take your listening/monitoring to the next level, then, yes, I would upgrade. Not only can you take advantage of the RSPdx’s enhanced performance, but the RSPdx affords you three antenna ports, and has a more robust front end.
Question: “I have an RSPduo. Should I buy the RSPdx?”
My recommendation: I’m a big fan of the RSPduo. Unless you’re a dedicated mediumwave/longwave DXer, or you’d just like to add another separate SDR to your radio arsenal, I wouldn’t rush out to buy the RSPdx.
And while I’m offering advice, I’d like to offer my standard two cents on the subject of performance optimization: a radio is only as good as its antenna!If you have a compromised antenna, invest in your antenna before upgrading your radio. You’ll be glad you did.
Conclusion
Happily, I can recommend the SDRplay RSPdx without hesitation. This latest iteration of the RSP series SDR is a proper step forward in terms of performance and functionality––obviously implementing years of customer feedback.
SDRplay also has a proven track record of innovation and customer support. Their documentation, video tutorials, and community are among the best in the industry. Purchase with confidence.
Many thanks to SWLing Post contributor, Mei Tao, who writes:
Yesterday, I received a new radio: the HanRongDa K-603, which was sent to me by the manufacture.They want me to test this prototype machine in order to find any bugs. If there is nothing to fix, I believe this radio will hit the market in this or next month.
K-603 is a small portable radio which also has some great functions. Its major features include:
FM, AM, and SW bands
Bluetooth 5.0 connection
TF Card Player
Recording function
Line in
LCD can display three different languages,English?Chinese and another foreign language.
Powered by the BL-5C Li battery
MW channnel space can be switched between 9KHz adn 10KHz.
Tuning methods: Scan, ATS, and direct key entry
The designer told me that this K-603’s fm coverage is from 87MHz to 108MHz, but they will extend it to 64MHz in the next version. That’s really good news.
In a few days, I will test it carefully. If necessary, I will make side-by-side comparisons with my own Tecsun, Sangean, Radiwow, and Degen radios. Then i will present some text and video reviews.
I would like to share some pictures of this new radio with you and other BCLers
Best wishes to you!
Photos
Thank you, Mei Tao! We look forward to your review of the HanRongDa K-603. Yes, please let us know how it compares to your other receivers. We also look forward to any update regarding price and availability. Thanks for sharing those photos!
Important note: like the Eton Elite Executive deal we posted recently, this promotion is noted as a “limited time” deal. It seems that when they run out of their current stock, you may be able to still find the promotional price via Eton, but the shipping date may be pushed out several weeks.
Many thanks to SWLing Post contributor, Mark Fahey, who left the following comment on our PL-880 review:
I’m reading this old post as I am a new user of the PL-880. I have it as my bedside and coffee table receiver in my house up in the Indonesian jungle.
I love it! Wished I purchased it months ago.
Until the PL-880 arrived I was using an ATS-909X up here – and seeing Thomas mention it here I thought I would ask about it.
I have owned 3 x ATS-909X over the years, two white and my most recent (about 2 years ago) is the black model. Every single one of them has the most frustrating key not functioning as you would expect bug. It like the keys are “sticking”, it’s not a mechanical problem, but something with the keyboard electronics. The 1st one I brought when the ATS-909X was basically unusable due the keyboard. The later purchases somewhat better, and the last Black one the best of the bunch with a software version that was supposed to fix the problem. All that said even the Black one is pretty crappy with unresponsive keys (unless you press hard and slowly – ie not rapid and fast sequences of key pressing).
Am I just suffering the effects of bad karma, or is everyone’s experience of the ATS-909X the same.
I’m so pleased I’m now using the PL-880. No problems, no crappy keyboard, just a great experience!
Cheers,
Mark
I’m glad you’re enjoying the PL-880, Mark. You’re right: it’s a brilliant portable.
Post readers: Have other ATS-909X owners experienced this problem with unresponsive keys? Please comment!
Yesterday afternoon, the family and I spent some time at my happy place: Mount Mitchell State Park. This might be our last visit there until spring of 2020 since the Blue Ridge Parkway is often closed during the winter.
Yesterday was unseasonably warm at 48F (9C)–a shot of warm weather before an Arctic front moves in tonight dropping temps to about 10F (-12C) and, likely, dropping 1-3″ of snow as well.
The afternoon at Mount Mitchell gave me a little time to play radio, of course, and put my recently acquired Sony ICF-7600A on the air.
How did I acquire the Sony ICF-7600A? Via the generosity of SWLing Post reader, Ed Earps.
Ed reached out to me after I made the following comment in a recent post:
“The ICF-7600A is a cool analog portable and one I’ve thought about acquiring at some point.”
Ed contacted me immediately:
“Thomas, if you would still like to acquire a ICF-7600A, I have one I would give you. This would be in appreciation of all the work you do in writing the SWLing Post blog.”
A few days later, the ICF-7600A with original box and accessories arrived. Wow!
Thank you so much, Ed! Over the years, members of the SWLing Post community have been so kind and so generous, it makes a guy feel humbled and appreciated. Thank you!
The ICF-7600A fits perfectly in my Red Oxx Hound pack.
I’m loving the ICF-7600A.
There’s something so authentic about tuning a good analog portable. It’s hard for me to describe, but I can certainly say it always takes me back to my radio roots.
The ICF-7600A has a low noise floor and seems to be incredibly sensitive. I easily snagged several stations on 31 meters, but ended up enjoying music via All India Radio while brewing a little coffee with my alcohol stove (handmade by my buddy, Greg–thanks, Greg!).
Hey, when you’re a coffee snob, you brew where you are!
But I digress…
I’m especially impressed with the ICF-7600A’s mediumwave performance. I logged a number of benchmark daytime and greyline stations yesterday. I haven’t opened the ‘7600A, but I imagine it has a decent ferrite bar inside based on its overall performance on the AM broadcast band and its nulling capabilities.
Next time, I’ll bring the AN200 mag loop and couple it with the ‘7600A. I’m pretty sure that’ll make for a winning combo.
All-in-all, I couldn’t have asked for a better day: the weather was wonderful, the coffee freshly-brewed, and the gifted ICF-7600A was the perfect radio companion as our family soaked in the scenery after a hike to the summit.
I’m often accused of being a radio “enabler.” Truth be told, I wear that badge quite proudly. I’m passionate about communications equipment and I suppose it shows especially here on the Post.
But radio “enabling” is a two-way street. I can’t count the number of times that I’ve made impulse purchases based on feedback and tips from SWLing Post readers. Yesterday was one of those days.
The tip
Last week, SWLing Post contributor, Rand (KS4L), sent me a link to an ad for a Drake SW8 on QTH.com’s classifieds site. Here’s the description and original photo:
Nice Drake SW8 Communications Receiver
Nice physical and working condition Drake SW8 portable communication receiver covering 100 to 30,000 kHz in AM, USB and LSB modes with backlit LCD panels. The VHF aeronautical band is also featured (118 – 137 MHz). For portable or field use, can be powered from 6 D cells and use the internal pivot point 41 inch telescopic whip. Comes with original manual, CD and 120VAC power pack with cable. Has an eHam review rating of 4.7 out of 5. From a non smoking environment.
Asking 250 shipped.
Randy sent this tip mid-week and I tried to ignore it. I knew it might not be a stellar deal, but it certainly wasn’t over-priced either.
The SW8
I don’t think Randy knew this, but I’ve always wanted an SW8. My buddy, David Goren, recommended this receiver ages ago, Each time I’ve stayed at his home he magically made an SW8 available as my bedside radio in the guest room. (That’s some serious radio hospitality!)
Once, many years ago, I actually agreed to purchase an SW8 from a seller in British Columbia, but the deal fell through for some reason. If memory serves, he damaged the radio in the process of packing it. I believe I agreed to pay $450 for it, but that was probably 10 years ago.
I kept Randy’s tip and link in my action items list and decided that, if still available, I’d post it as a radio deal here on the SWLing Post.
Yesterday morning, the SW8 was still showing as available so I started a post. Being the radio enabler I am, I started writing about how much I’ve always wanted to own an SW8…how I love the simple front face plate, the display, the fact it can be powered by batteries, and how I think it’s quite a capable little receiver.
Then I stopped writing, mid-sentence and asked myself… “Will I regret not grabbing this SW8?”
My “radio bux” fund is incredibly low at the moment, mainly due to recent travels and budgeting for no less than three radio conventions next year. Also, this is the time of year when several annual fees/subscriptions are auto-deducted from my account–including hefty hosting fees for the Shortwave Radio Audio Archive.
Still, I had *just* enough money to at least make an offer and knew if I “thinned the radio herd” here at SWLing Post HQ, I could probably replenish the amount in a month or so.
Since this was a classifieds ad, my next step was to go through an extensive checklist to make sure the seller was who they claimed to be and that there were no signs of this being a scam. Everything checked out. (I’ll make a note to publish a post about my process in the near future).
I contacted the seller and we agreed on a price of $220 shipped. I put his check in the mail, and he even shipped the radio same day and provided a verified FedEx tracking number.
I’ll admit it: I’m stoked!
I look forward to putting this Drake SW8 through the paces and especially loading it with batteries and taking it to the field. I know–in terms of performance–it won’t be my best receiver, but I know it’ll provide hours upon hours of radio fun, and that’s what it’s all about!
Post readers: What do you think? Have I made a mistake, or did I get a good deal? I’d love to hear from those of you who’ve been owners of the venerable Drake SW8!
