Yearly Archives: 2018

95th anniversary of Czech radio’s first broadcasts

Czech Radio’s main headquarters in Vinohradská street in the centre of Prague, photo: Lenka Žižková

Many thanks to SWLing Post contributor, David Iurescia (LW4DAF), who shares the following news items from Radio Prague regarding the 95th anniversary of Czech Radio’s first broadcasts:

Listening Sessions at a Prague Cinema: Czech Radio’s First Broadcasts Recalled, 95 Years Later

A historic moment occurred at 20:15 on Saturday May 18, 1923 when the first ever broadcast by Czechoslovak Radio was made from a tent at a military air base in Prague’s Kbely district.

After the United Kingdom, Czechoslovakia was the second country in Europe to launch regular radio broadcasting.

Zuzana Foglarová is communications manager at today’s Czech Radio. Speaking at a new exhibition of radio technology at the station, she describes the scene in May 1923.

“Above all it was very simple. There was one tent, which had been borrowed from the scouts. On the floor in the tent was a piano and stool. There was also a table for the presenter, technicians and so on. There was only one microphone, and the story goes that if somebody was playing the piano and somebody else was singing, the latter had to sit under the piano so the microphone could pick up all the sounds.”

Many of the first listeners 95 years ago were waiting to hear the signal come through at a cinema just off Prague’s Wenceslas Square.[…]

Click here to download recording.

Click here to read the full article at Radio Prague.

The spectacular Rudgers?v Palace built in the Neo-Classicist style is home to Czech Radio’s Ostrava studios, photo: Daniel Martínek, Czech Radio (Source: Radio Praha)

Past and Present: A Gallery of Czech´s Radio Buildings

Czech Radio is celebrating its 95th anniversary this year. The Czech national radio broadcaster has come a long way since its pioneering days. Today it is the biggest radio broadcaster in the country with 9 channels, manned not only by its Prague staff but 14 regional branches providing news and reports from around the country. The station’s buildings are also an important part of its history. On the occasion of Czech Radio’s 95th anniversary we have prepared a photo gallery of its buildings, some of them valuable architectural landmarks.

Click here to view the photo gallery at Radio Prague.

Spread the radio love

VORW Radio International updated schedule

Many thanks to SWLing Post contributor John with TheReportOfTheWeek who writes:

Since our last update, a few additional time and frequency changes have been made to our shortwave airings of VORW Radio Int. Each broadcast features a fun hour of misc talk and commentary as well as a wide variety of listener requested music!

The full schedule is below, with changes being highlighted.

Thursday 1000 UTC – 5950 kHz – WRMI 100 kW – Western North America
Thursday 2000 UTC – 7780 kHz – WRMI 100 kW – Eastern North America
Thursday 2100 UTC – 7490 kHz – WBCQ 50 kW – Eastern North America
Thursday 2200 UTC – 9955 kHz – WRMI 100 kW – South America
Friday 0000 UTC (Thu 8 PM Eastern) – 7730 kHz – WRMI 100 kW – Western North America
Friday 0000 UTC – 5950 kHz – WRMI 100 kW – Central America (ex. 9455 kHz)
Friday 0000 UTC – 9395 kHz – WRMI 100 kW – North America
Friday 0100 UTC – 7780 kHz – WRMI 100 kW – Eastern North America & Europe
Friday 0100 UTC – 5850 kHz – WRMI 100 kW – North America
Friday 0400 UTC – 7730 kHz – WRMI 100 kW – Western North America (new. Test transmission for West Coast Listeners)
Sunday 2000 UTC – 9395 kHz – WRMI 100 kW – North America
Sunday 2100 UTC – 7780 kHz – WRMI 100 kW – North America

Questions, comments, reception reports and music requests may be sent to [email protected] PayPal donations are also welcome at that email as this is a listener funded broadcast.

Reception reports will receive a QSL!

All the best,

John

Spread the radio love

FTIOM & UBMP, May 27-June 2

 
From the Isle of Music, May 27-June 2:

This week we re-broadcast a conversation that we had with Arturo O’Farrill in the Iris Jazz
Club in Santiago de Cuba in December 2015 and listen to some excellent Cuban Jazz and dance music.
1. For Eastern Europe but audible well beyond the target area in most of the Eastern Hemisphere (including parts of East Asia and Oceania) with 100Kw, Sunday 1500-1600 UTC on SpaceLine, 9400 KHz, from Kostinbrod, Bulgaria (1800-1900 MSK)
2. For the Americas and parts of Europe, Tuesday 0000-0100 UTC on WBCQ, 7490 KHz from Monticello, ME, USA (Monday 8-9PM EST in the US). This has been audible in parts of NW, Central and Southern Europe with an excellent skip to Italy recently.
3 & 4. For Europe and sometimes beyond, Tuesday 1900-2000 UTC and Saturday 1200-1300 UTC on Channel 292, 6070 KHz from Rohrbach, Germany.

Uncle Bill’s Melting Pot, Sun, May 27 & Tues, May 29
Episode 64 presents the music of the delightful singer Irina Sarbu and the Ethnojazz Project, an award-winning ensemble that fuses Romanian music and Jazz.
1. Sundays 2200-2230 UTC (6:00PM -6:30PM Eastern US) on
WBCQ The Planet 7490 KHz from the US to the Americas and parts of Europe
2. Tuesdays 2000-2030 UTC on Channel 292, 6070 KHz from Rohrbach, Germany for Europe. If current propagation conditions hold, the broadcast should reach from Iceland to Western Russia, Scandinavia down to North Africa and the Middle East, AND a long bounce to parts of New Zealand.

Spread the radio love

Dan spots the ultra rare Hammarlund SP-600 JX21A on eBay

Many thanks to SWLing Post contributor, Dan Robinson, who discovered a very rareHammarlund SP-600 JX21A on eBay. Dan writes:

Collectors of classic boatanchor gear know what has been probably the rarest of tube sets year after year, decade after decade. That set is the Hammarlund SP-600 JX21A.

While there have been numerous JX21s on eBay, there has not been, to my memory, a single JX21A appearing. This particular model was a version of the SP-600 that was produced in small quantities in the 1960’s, and according to one writeup was the only one with a product detector and switchable sidebands. According to Radiomuseum it was the last model in the SP-600 series, and was recognizable for its knobs which were different because the silkscreen information was printed directly on the front panel rather than on the edge of the knob skirts.

According to Les Locklear’s excellent history of SP-600 models, the JX21A was produced between 1969 and 1972.

Now, an ultra-rare SP-600 JX21A has appeared on eBay. Like other models in the series, this would likely require replacement of numerous capacitors and a thorough refurbishment. The seller in this case has started bidding at a very low level, but if history is any guide, a rare model like this one may indeed go for thousands of dollars when all is said and done at the end of the auction.

Click here to view the Hammarlund SP-600 JX21A on eBay.

Amazing!  Thank you for sharing, Dan! What a gorgeous set. Though the seller states it’s in need of restoration, I’m pretty sure this one will get snagged up at end of auction. I’m very curious where the final price will land.

Are there any SWLing Post readers who own an SP-600 model–or the JX21A?  Please comment!

Spread the radio love

2018 Hamvention photos: Inside Exhibits

The Flex 6600M is a handsome standalone SDR transceiver.

Saturday and Sunday were long (though fun–!) days at the 2018 Hamvention–I did have a moment to visit most of the inside exhibit tables. Most of the following photos were taken (in no particular order) in the main Hamvention buildings and tents at the Greene County Fairgrounds.

Again, it was especially fun meeting so many SWLing Post readers and contributors in person!

Note that the folling photos are in no particular order. Click here to view photos of the 2018 Hamvention flea market.

Click on the photos below to view larger images:

Spread the radio love

2018 Hamvention photos: Friday Flea Market

It was a long day at the 2018 Hamvention Friday, but we had a brilliant time. As always, it’s a pleasure to meet so many SWLing Post readers and contributors–thank you for stopping by!

Below, I’ve posted photos I took at the Hamvention Flea Market this morning. Note that most of these photos were taken either prior to the flea market opening or just shortly after. The selection was pretty amazing. The rain did come and go throughout the day, but the recycled asphalt that was spread between the aisles did help keep mitigate the mud situation.

Click on the thumbnail to expand each photo. I’ve tried to include price tags when available although the camera phone I used didn’t have the sharpest focus! I plan to post inside exhibit photos tomorrow.

 

Spread the radio love

A review of the SDRplay RSPduo 14-bit dual tuner SDR

The new SDRplay RSPduo

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.

Performance

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.

Comparisons

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:

Low Pass

  • 2 MHz Band Pass
  • 2-12 MHz
  • 12-30 MHz
  • 30-60 MHz
  • 60-120 MHz
  • 120-250 MHz
  • 250-300 MHz
  • 300-380 MHz
  • 380-420 MHz
  • 420-1000 MHz

High Pass

  • 1000 MHz

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!

Click here to check out the RSPduo at SDRplay.com.

Spread the radio love