Category Archives: Longwave

SDRplay announces the RSPduo: A 14-bit Dual Tuner SDR

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).

For more information visit the SDRplay website on www.sdrplay.com

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

Spread the radio love

Bill scores a homebrew LW/MW magnetic loop antenna

4 Replies

Many thanks to SWLing Post contributor, Bill Hemphill (WD9EQD) who shares the following:

I went to the Warminster Amateur Radio Club (WARC) hamfest [yesterday] in Bucks County, PA. For some time, I have been thinking about making a loop antenna for AM DXing. It was my lucky day. When I walked to the inside tables, on the very first table was this homemade loop antenna gentleman was selling from an estate.

I snatched it up for $40.

Attached are some photos of it. It’s 25” by 25”, with a swivel base. There are 23 turns of wire and I have no idea what size the capacitor is. I did some preliminary tests and it tunes from 280 kHz to 880 kHz. So it’s the covers the high half of the long wave band and the low half of the AM band.

It’s very well made and I fugue I can modify it to cover the entire AM band.

[…]I hooked the SDRplay RSP2 to it and was getting good signals of major stations all the way to 15 mHz.

That’s with it sitting on my dining room table. Of course the capacitor wouldn’t peak the signals.

So it was a great day at the hamfest!

Indeed that was a great find, Bill! Someone spent a decent amount of time building that furniture-grade loop support. Indeed, it’s very reminiscent of 1920s-30s mediumwave loops!

What I love about your loop (and that of Thomas Cholakov) is that one can see how simple these antennas actually are to build. The only complicated bit is the support, but even that’s simple if you use the shield of a heavy coax or flexible copper tubing.

Thanks for sharing and enjoy logging DX with your new-to-you loop!

Spread the radio love

Grimeton Radio / SAQ LF transmitter on the air May 1, 2018

Possible First 2200-Meter Transatlantic Ham Radio Contact

1 Reply

(Source: ARRL News via Mike Hansgen)

In late March, Paul Kelley, N1BUG, of Milo, Maine, completed what may have been the first transatlantic 2200-meter contact by a US radio amateur under Amateur Radio rules. Signals in this part of the spectrum and lower previously have spanned the Atlantic in one direction, and Canadian radio amateurs have reported transatlantic contacts on the band dating back several years.

“To the best of my knowledge this is the first transatlantic two-way QSO from the US on 2200 meters under Part 97 operation,” said Kelley, who told ARRL that he gravitates toward the more challenging, “weak-signal” aspects of Amateur Radio and has been experimenting and DXing for 37 years now.

“2200 meters is my new passion, and I am having a lot of fun with it!” he said. I had been dreaming of — and working toward — a transatlantic QSO on 2200 meters for some time. Recently, I asked Chris Wilson, 2E0ILY, if he would be interested in trying to work me on DFCW60 mode. Chris and I have heard each other on WSPR, but he does not hear me well enough yet for a JT9 or other digital QSO. Chris agreed to try DFCW60 — dual-frequency CW, 60 second dit length.”

This was not a quick contact. It took four nights to complete, using night-by-night sequencing. Kelley called that “the minimum possible time” for such a contact, which included an exchange of complete call signs, signal reports, and acknowledgements. Kelley said they used the TMOR reporting system, borrowed from the moonbounce world.

“The QSO was completed at 0020 UTC March 28 when I received ‘R’ from Chris,” Kelley said.[…]

Click here to read the full article on the ARRN News site.

Spread the radio love

Indian Standard Time via new longwave site

1 Reply

(Source: Southgate ARC)

India to employ long wave radio technology

Two towers, about three times the height of the Qutab Minar, are likely to be erected at as-yet-undecided locations in the country for disseminating Indian Standard Time.

The National Physical Laboratory, an organisation charged with ensuring that Indian time stays accurate, has signed an agreement with IFR Information Dissemination Services (IFR) Ltd., which will set up the towers and employ long wave radio (LWR) technology to purvey this time to a range of users, from phone companies to railway stations. Customers will need a microchip that can be embedded into everything, from wall-clocks to servers.

“Long range radiowaves from the towers can be reliably transmitted even during major disasters. Other than time, information such as a tsunami warning or weather warnings can also be sent,” Pawan Kumar Kasera, director, IFR, said at a press conference. IFR is affiliated to the Germany-based EFR GmbH, which is in the business of providing similar services in Germany.

The company now requires a plethora of permissions from other government departments to host these towers, each with a range of 1,000 km, and an investment of about Rs. 600 crore, which it will raise privately.

The NPL would help IFR keep their caesium clocks (located in the tower) calibrated but wouldn’t be involved in setting up the infrastructure related to time dissemination. Last year, the Council of Scientific and Industrial Research-body had tied up with the Indian Space Research Organisation to provide time-related services for its satellites. “The advantage of LWR is that the waves travel close to the ground and so can reach out to far-flung locations, even to submarines. We’d advertised through newspapers asking private players to help us disseminate NPL-time to the public. Five companies approached us and we’ve selected IFR,” Dinesh Aswal, director, NPL, told The Hindu .

http://www.thehindu.com/todays-paper/tp-national/coming-huge-towers-to-publicise-right-time/article23377284.ece

Click here to view this article at the Southgate ARC.

Spread the radio love

Ever Ready Model N attache case radio spotted in charity shop

The XHDATA D-808 and longwave: how to build an effective antenna

5 Replies

Many thanks to SWLing Post contributor, Mad Radio DXer, who writes:

I said I would share my results for attempting to receive LW signals on the XHDATA D-808, & if I can use a longwire to improve reception on this radio. This was after posting videos when I used around 50 metres of longwire connected to the D-808 for improved Medium Wave reception & to prove it works.

This first video shows that it is not possible for LW, no matter if I connect the 50 metres longwire to the 3.5mm input or the whip antenna. I also compare reception of the same station with the Degen DE1103 PLL using the 3.5mm input. The Degen DE1103 still had better reception even when I used the whip antenna extended at the very minimum when using the LW/MW external antenna trick. I know I should have used the internal ferrite antenna of the Degen compared to the D-808, but in any case I did try off camera & reception was about the same. So unfortunately the D-808 was never going to win this round.

However, there is a solution.

The answer? Build yourself a Long Wave induction antenna as shown in the second video [below]. I made one some time ago, as I grew frustrated at how poor the Tecsun radios were on this part of the band & that there were no LW induction antennas available to buy. I tried a signal on 207 kHz which is RÚV Rás 2 from Iceland. Either a radio with a very good internal antenna or a good external antenna is needed to receive this station at my QTH in southern England.

Placing the D-808 on the induction antenna resulted in a very pleasing result, which was it did get reception of Iceland on 207 kHz. So this shows that it is possible to DX on the LW bands with the D-808 with some “external help”.

For anyone interested making a LW induction antenna as shown above, here is a link to a video that has basic instructions & further results. It may be a very simple build & finish what I did, but for me the most important thing is that it works.

I hope my comments & videos will be a great help to all. Happy DXing.

Regards,

Mad Radio DXer.

Excellent–your comments and videos are most welcome! There are quite a number of SWLing Post readers who are avid longwave DXers. I love the simplicity and efficacy of your longwave antenna–something anyone could build. A clever upgrade to the affordable D-808. Thank you for sharing!

Spread the radio love