Wednesday, November 27, 2019

QSL: KGMI Bellingham WA 790

KGMI is a station I wanted to catch, literally for decades. In mid-November, for once the dominant KCAM-AK was weak, and KGMI had a fair signal along with stronger KGHL-MT. Friendly email response last night.
The reception was just after KJRB Spokane's new very low night power (30 watts) had come into effect. This surely helped too, since KJRB used to be quite dominant during conditions like this.

Friday, November 15, 2019

More Options for the Arctic Norway KiwiSDRs

A KiwiSDR, first named KongSDR, later ArcticSDR, has been operative for the past few years using a variety of antennas. In anticipation of a new fiber connection, to replace the very expensive 4G connection, I bought another Kiwi a few months ago. From early autumn, the ArcticSDR has been connected to an antenna pointing towards Far East Asia and the Pacific. The back lobe should work well towards western Europe and South America. Another one, the KongSDR (reborn!) has been connected to a North America beverage, but not announced publicly to avoid too much usage of the 4G line.

Last week however, fiber was installed, and today I finally got time to reconfigure my KiwiSDRs so that both are public. See links to the right. So! I hope that I can wave goodbye to the somewhat flimsy 4G.

The new connection not only helps the Kiwis, but the main gear too, comprising PCs, SDRs and other equipment for three DX-ers in Kongsfjord. A total of 14 devices are connected to the fiber via ethernet. And although I haven't chosen top speed (yet), the current 50/50 connection seems to work well.

Saturday, October 26, 2019

KONG39 Day Nine (October 26)

Note to self: Never underestimate the power of the ionosphere, even during stormy conditions!

The 340-degrees beverage performs admirably, it is extremely quiet and sensitive, and is able to pick up exceptionally weak signals. During the night, we had a couple of spot openings towards California/Arizona/Nevada, with some excellent stations noted, such as: KWWN Las Vegas NV 1100, KINO Winslow AZ 1230, KVMI Tulare CA 1270, KFIV Modesto CA 1360 and KNIM Maryville MO 1580. Most of them during a five-minute opening. Carriers were barely visible on the waterfall.

Later in the day we went to Mount Loran to dismantle the 1000-metre beverage and the rest of the equipment there. Sweaty, we spent an hour in the Guesthouse sauna before we had fried saithe fillets for dinner, and assorted cheese + chocolate cake with custard for dessert.

Sunday morning is departure day for Ole and OJ. I will spend a few more hours, to empty the summer water supply and prepare the house for the coming winter.

A bit windy on Mount Loran, otherwise quite nice weather, hovering around the 0 Celsius mark.

We hope you have enjoyed our reports! Next year, same place! "Thanks for listening" from Ole Forr, OJ Sagdahl and Bjarne Mjelde.

KONG39 Day Eight (October 25)

Not much to report!

Varying, but mostly weak signals from North America overnight, and Asian signals were weak even into the evening. Recordings from previous days kept us busy! Lots of interesting stations to find. The overnight waterfall says it all. 

So! Dinner time! For starters we had Västerbotten pie with Kalix löyrom (roe from a small fish, lagesild) and a Schwedhelm white wine. The main course was a leg of lamb, baked for 8 hours at 75 degrees Celsius. Served with a paste of root vegetables and sauce. A Californian Vine Starr Zinfandel from 2017 went very well with the lamb. We were going to have assorted cheese for dessert, but it was just too much!

Today is the last full KONG39 day, and we will dismantle the Mount Loran site before it gets dark. Maybe some pictures coming up.

Windy in the evening. Temperatures just above freezing and not much snow but icy roads. We're hoping for decent weather (and better prepared roads) when we collect our Mount Loran gear.

Friday, October 25, 2019

QSL: CJSN Shaunavon SK 1490

I have been wanting to hear CJSN since I logged their "sister" station CKSW Swift Current 570 in December 1979. Finally, late September they had a good signal on 1490 and I was able to pick a decent ID from the station.

Email QSL today! So, Swift Current/Shaunavon region of Golden West Broadcasting finally complete after just under 40 years... CKSW is a very dominant station by the way.

KONG39 Day Seven (October 24)

And the Sun said: Ka-Boom! I shall stir up the ionosphere so that all DX-ers shall shout "Yikes! What happened"? And so She did.

And after we had shouted "Yikes! What happened", we looked at our Yaslogs, and yikes! it was not a pretty sight. On the 50-degrees Asia/Pacific beverage, the signal levels increased as normal up until 11:00, followed by an almost total blackout. Later in the day the signals recovered somewhat, but with varying levels and with nothing interesting.

11:00: The Yikes Effect

After analyzing the North America beverages we did see very good signal levels from around 22:00 until 10:00 when the signals plummeted and never really recovered.  Nothing really superb from that night and morning, but a few not very usual ones: KQCV Oklahoma City OK 800, KYWN Meridian ID 890, KEIN Great Falls MT 1310 (has been silent for quite a while), KGEN Tulare CA 1370, KDOM Windom MN 1580 and also KQFN Tempe AZ 1580.

In the afternoon, I got one step closer to a fiber connection as the fiber boys came and blew 150 metres of fiber cable in the ground to my house. And we had a most pleasant visit from radio amateur and whisky connoisseur, LA9VFA Olav.

Then, all that remained for the day was dinner! For starters, we had tapas snack of various size and appearance. The main course was fish soup, based on superb quality haddock fillets. Other ingredients were chopped carrots, celeriac, potatoes, rutabaga, onions, garlic, red chili, ginger,  cream and some additional spices. We ate it all, accompanied with a Schwedhelm riesling from 2017. For dessert we enjoyed warmed cloudberries with vanilla icecream. Grappa went very well with the dessert! We left the rest of the icecream outdoor, and within minutes, Michael the Fox had taken it home to feed his pups (or so we'd like to think).
Serious dinner for serious DX-ers.

The weather was quite calm, around -2 all day, with some light snow in the evening. As I'm writing this, wind is gradually picking up and the mets say this afternoon will be a rather unpleasant one weatherwise. We will see!

Thursday, October 24, 2019

KONG39 Report Day Six (October 23)

HUGE signal levels! The day started just after local midnight with good daytime signals on the Mount Loran beverage, such as KUOM Minneapolis MN 770, KFUO Clayton MO 850 (followed by WQRM Duluth MN!), WCPC Houston MS 940 and WWRK Florence SC 970! 

Strong signal levels overnight, and some decent Pacific signals in the morning with Samoa-540 and Gold FM-990 to mention two. My KiwiSDR was packed with people chasing Samoa. I do expect they remember to tell the station the location they heard it.

The rest of the day, Asian signals were enormous, and hindered North America afternoon DX.

Dinner: Time for reindeer! For starters, we had spicy hummus with roasted chickpeas and artichoke hearts.    Reindeer tenderloins is a KONG signature dinner. Simply served with a paste of potatoes, sweet potatoes, carrots, celeriac and rutabaga, a red wine sauce and lingonberry jam. Wines: Cune Gran Reserva 2011 and Monterustico Dogliani 2017. For dessert we had another round of assorted cheese, and a Dow's Vintage Port 2005.

Weather was calm and dry most of the day, +2 Celsius maximum, but dropping to -2 in the evening. Late evening some light snow began to fall, and this morning, my car was whiter than normal.

Tuesday, October 22, 2019

KONG39 Report Day Five (October 22)


Signal levels didn't really begin to raise until 22:00, so we're still waiting for the GREAT evening daytime opening. Still, pre-midnight conditions provided one (temporarily undisclosed) new station, and signal levels were in fact excellent until sunrise reached the North American west coast after 14:00. Morning daytime signals noted from KUIK Hillsboro OR 1360, KVMX Olivehurst CA 890 and several others. And we haven't even begun to examine the Mount Loran recordings! Excellent signals also from Hawaii, and rare stuff from Alaska like KVAK Valdez 1230.

Pacific/Asia was a bit disappointing (again), but we did note both Kiribati stations (846 and 1440) with good signals very early in the day.

As usual, once every KONG we eat at Kongsfjord Gjestehus. We enjoyed an hour in their luxury sauna first, and was then served a superb Bacalao with an Amarone della Valpolicella 2018 red wine. Apple pie and Aquavit + coffee for dessert.

We're now hoping for the long-awaited daytime opening towards North America...

Weather was nice, relatively calm and sunny most of the day, temperatures just below 0 Celsius.

Never a blogpost without a picture - today's is a drone photo from the day showing the KONG HQ and its vicinity to the inhospitable Barents Sea. Photographer is Arnt Eirik Hansen. Do a search for his pictures, he does great stuff.

KONG39 Report Day Four (October 21)

The ionosphere is obviously still in a sort of disturbed mode. We can tell from the varying overall signal levels, fluctuations and how different areas are affected. Interesting! And frustrating - again we had interesting early signals from the Pacific that just disappeared. On the other hand, there were periods producing some interesting stations from North America.

NA stations started to fade in just after 22:00, peaked at 01:00 and were audible until around 12:00. Hawaiian stations came quite early, with very good signal levels. Some interesting stations from North America: 940 KVSH Valentine NE, 1180 WXLA Dimondale MI, 1190 WNWC Sun City WI, 1560 KBEW Blue Earth MN.
Below is an overnight spectrum on 1180 kHz from the Mount Loran beverage. A minimum of 15 carriers are seen. So, there is potential!

Mount Loran beverage, overnight on 1180 kHz. The slight frequency shift is due to ambient temperature changes.

Asia, although not properly checked yet, were mostly dominated by the common ones.

Very windy overnight, so we needed to add some heating to the old, poorly insulated farmhouse. During the day the wind was only light, and the temperature tipped above the zero point a couple of hours. Mostly dry.

Yesterday we had a rather massive calf shanks in Barolo dinner. The leftovers made an excellent stew when we added vegetables. For starters though, OJ made a delicious salman tartar - fresh and smoked salmon, red onion, garlic and Worchester sauce. Chopped chives on top. Recommended! A Knewitz riesling made a great companion. For dessert, chocolate cake with raspberry jam and port wine. It really doesn't get more high-carb than this!
Salmon tartar.

I never got round to take pictures, so here is one taken a rainy summer day, overlooking the hamlet of Kongsfjord. The KONG HQ is mostly obscured by the haze.
Kongsfjord, facing northeast

Sunday, October 20, 2019

KONG39 Report Day Three (Oct 20)

Another day with no trace of daytime conditions. Reasonably good signal levels towards North America overnight, but at 05:00 conditions made a deep dip, and remained at low levels throughout the day. The usual west coast stations were well audible, in addition to stations like KLGN Logan UT 1390, KQFN Tempe AZ 1580 and KWBG Boone ID 1590. Hawaiian stations were audible with excellent signal levels until well into the afternoon. Heard them all before, though.

From the 340-degreees, west North America beverage
Pacific signals started extremely early, around 08:30 with good signals from Kiribati-1440, Marshall Islands-1098 and Tonga-1017. We had hopes that this would be THE Pacific opening. However, the signals fizzled out into nothingness, with little or no interesting stations to be heard during the rest of the day.

So! Dinner! For starters, we had duck liver paste on roasted bread. The main course was calf shanks cooked four hours in Barolo red wine. Dessert: Chocolate pudding and custard with Amaretto and Grappa!

Weather: Relatively calm and sunny in the beginning of the day. The skies remained clear, but the wind increased to strong breeze in the afternoon and evening. -3 Celsius, so with the wind chill factor Sunday was definately a chilly day!

310 beverage. Contrails from  Qatar 739 from Doha to Los Angeles.

Rough shores near our site.

KONG39 Report Day Two (Oct 19)

Overnight conditions towards North America were not spectacular, but some stations noted, such as KCSF Colorado Springs CO 1300. Another surprise was KARN Little Rock AR 920. KXPN Kearney NE 1460 has been noted on several occasions, too often for only 56 watts at night we think.  Very strong signals from Hawaii from around 09:00 and into the afternoon.

Also a few NZ showed up at around 10:00, but after signal levels did a deep dive, NZ never recovered. Australia did show up with some stations at excellent signal levels - 2RN Wollongong 1431 was the only noteworthy.

The rest of the day was rather uneventful, except we tested a few nice beers, such as Djævelsk Fruktig Double IPA, Survival of the Hoppiest Double IPA and Oppigårds New Sweden IPA.

Dinner is something we always look forward to. For starters we had bruscetta consisting of fresh, no-knead bread with small tomatoes, fresh basil and parmesan cheese (and a handful of garlic).

The main course was fresh salmon with carbonara (and a handful of garlic), and we ended up with assorted cheese (without garlic). Calles's Riesling for the starter and main course, and a Niepoort port wine for the dessert.

Temperatures from 0 to -2 Celsius, snow showers but otherwise sunny as you can see below.

The other picture shows a view, although limited, to the north. Two beverage antennas actually cross the dirt road but you probably can't see them.

Sunday morning status: Weather much the same. Good signal levels overnight!

View to the south

View to the north

Saturday, October 19, 2019

KONG39 Report Day One (Oct 18)

OJ Sagdahl, Ole Forr, Bjarne Mjelde (host)

KONG39 started a bit earlier than expected. Ole had made the 1000-km drive from Andøya in record  speed, and in winter conditions, and arrived at 06:00, as Bjarne was driving to Kirkenes to pick up OJ at the airport. At 11:20, when we were stuck in a road maintenance queue, Ole texted a New Zealand alert! We were quick to pick up our laptops and connect to our KONG SDRs. Amazing signal levels! Alas, later analysis revealed that most stations were heard before - still it was by a large margin the best NZ opening so far this season. It's always nice when 2-kW 1XX in Whakatane, NZ dominates over 100-kW JOLF!

Remote NZ DX in the car

We arrived in Kongsfjord around 13:00 and went directly to our Mount Loran 1000-metre site to replace the battery and other equipment. Asia conditions in the afternoon and evening was rather uninspiring, and we had the traditional first-day meal, home-made fish gratin with chocolate pudding & custard for dessert, in the evening.

Temperatures around 0 Celsius, a "refreshing" breeze and mostly dry between the occasional snow shower. Icy roads much of the drive. In the morning of the 19 it's sunny, but snow showers looming outside the coast to the north. Superb signals from Hawaii right now. More to come!

Saturday, October 12, 2019

QSL: CHRN Montreál, QC 1610

CHHA Voces Latinas usually dominates 1610, but in mid-September, another voice dominated, that of Radio Humsafar. CHRN caters for the South Asian communities in Montreál, with programming in Punjabi, Hindi, Urdu and English. Short but friendly email response from the station's President today. Quebec verie no. 25 and North America X-band verie no. 50.

Tuesday, October 08, 2019

QSL: KXXX Colby KS 790

KXXX has been on my wish list since I saw it logged several times in the 1980's in Sweden and Finland. But did I ever hear it? No! Until a few days ago, when excellent spot conditions appeared for a little while during the onset of a solar disturbance. The Mount Loran 1000-metre beverage was able to pull in a rather weak, albeit legible signal. The next full hour, the signal was gone and KGHL/KFGO again dominated the frequency. Thanks Paul Walker for submitting the contact address.

Friday, September 27, 2019

Recording and Playing Back MW IQ Files: A Software Comparison

Recording and playing back IQ files is a vital part of the MW DX-er's hobby. With lots of SDR software available, how do we do it? What are the pros and cons? In this article, I have tried to make a (relatively) unbiased comparison between the most popular programs today. If anyone do not agree, that is fair enough, mileage and preferences vary.

Saturday, September 21, 2019

Chrome Remote Desktop - An Alternative to Costly Remote Control Programs?

I was advised by Swedish DX-er Stefan Wikander that Chrome Remote Desktop worked very well with his remote Perseus location. Now really, I thought, I tested Chrome's remote solution several years ago and it was a complete disaster at the time.

Over the years I have used LogMeIn (became very expensive), Teamviewer (kicked me out of my free, Personal account) and Splashtop (present choice, excellent tool, USD 100/year). And tested many more. Anyway, I know Stefan as a sensible man, so I decided to test CRD. It has in fact come a long way.

CRD is a "free" extension in Chrome (you pay with your user data), so obviously you need the Chrome browser, and you need a Google account. Chrome needs to be synchronized over the PC or PCs you want to control. Setup is relatively straightforward. I set up one PC to access two other PCs, and when I opened the extension, I was met with this "welcome" page:

When I clicked on the "Smøla 290" PC on top, it opened as a new tab in Chrome, and the PC displayed like this:

It actually loads very quickly, faster than Splashtop. Audio quality is on par, video quality a bit better than Splashtop. What really surprised me was there was no noticeable lag, much better than both Teamviewer and Splashtop. Your remote PC can be bookmarked for even easier access.

CRD doesn't have many features, so for a professional user CRD may not be the optimal solution. For the DX-er however: Good video, good audio, file transfer (to and from the unit), copy & paste. Windowed and full screen. Not much more to ask for!

October 2019 update: On one occasion however, one of my remote PCs refused to connect. I was able to connect via Splashtop, so the connection was ok. I restarted the PC several times with no effect. It turned out that Chrome on that particular PC had disabled its server function, so I had to set it up again. This casts some doubt over its reliability. I'm going to keep Splashtop, and use CRD as backup. See comments below.

Thursday, August 29, 2019

QSL: 4KZ Innisfail, QLD 5055

The 4KZ 1620 kHz 400-watt relay is quite easy to hear at my location, despite the 12,800 km distance.

Not so with their 1.3 kW station on 5055 kHz! After a few futile (albeit random) attempts, I decided in February to monitor and record three top of the hours every day. I also wanted to do an A-B comparison between the Airspy HF+ and the SDRPlay RSP1A. So both were connected to the same antenna, two different PCs with HDSDR running on both. After quite a number of days, the signal was finally readable.

The HF+ is known to be a very sensitive SDR, while the RSP1A is more average when microvolts are measured. So, there "should" be a difference in audio recovery, at least on threshold signals. There was. When signals are very weak and the noise floor is low, better sensitivity is indeed audible. Here is how 4KZ was heard at the time. Headphones recommended.

The 4KZ General Manger Al Kirton is a DX-friendy guy, and sent off a proper QSL card with a sticker and info in the mail.

Friday, August 23, 2019

Airspy HF+ Discovery: Sensitivity Measurements

Time to find out how sensitive the HF+ Discovery is! Since it is basically the same receiver as the HF+, with preselectors, I expected sensitivity on MW to be roughly the same. Which turned out to be true.
On 500 kHz, I measured -110 dBm, on 1000 kHz -111, and on 1500 kHz -110 dBm. Using SDR#, v.1708, 6 kHz bandwidth with AM mode, and a 30 % modulated, 400 Hz signal from the signal generator.

The "Receiver Sensitivity Measurements" table has been updated accordingly. Excellent numbers.

Tuesday, August 20, 2019

Airspy HF+ Discovery Has Landed

Well admittedly, the Norway transport was on road, taking twice as long as from Shanghai to Oslo. But it arrived! Just fired it up at my home in Tana, no antennas available, so only to get a feel of it (feels warm to touch) and do the latest firmware update. Sensitivity measurements will be done on Friday.

My kitchen weight says 32 grams. By a good margin the lightest SDR I've had so far.

Sunday, July 28, 2019

Antenna Test: The NTi MegaDipol MD300DX

Not much is happening DX-wise during the light Arctic summer, but I had the opportunity to check out a dipole antenna sold by, the NTi MegaDipol MD300DX.
For the time being, you can check it out yourself on my KiwiSDR, see link on the right hand side.

Beverage antennas are the norm at my KONG (Kongsfjord, Arctic Norway) location, because I and my co-users are exclusively MW DX-ers. For general listening, especially on SW, other antenna designs may be better, and for some time I have had a 70-metre longwire up as an all-purpose antenna for use with my KiwiSDR. Many years ago I tested a Mini-Whip antenna, and also the venerable Clifton Labs Z1501 active whip. Two years ago I bought a Wellbrook ALA1530LF for noise detection, and made a comparison with the longwire.
There is no doubt that a properly installed longwire antenna is very efficient on a broad frequency spectrum and may be the preferred alternative if space is not a limiting factor. But often space is restricted, necessitating more compact antenna designs.

Enter the NTi MegaDipol MD300DX. The MegaDipol, priced at EUR 400, comprises of an external antenna unit with two detachable 2.5-metre PVC-coated steel wire elements, and an internal power inserter which powers the external unit via the coaxial cable. The inserter can be powered from a 10-15 VDC supply, or from a 5 VDC supply such as a USB port with slightly less IP values. It is worth noting that the MegaDipol is an E-field antenna, so it should be placed in an electrically quiet environment. For omnidirectional reception, the elements should be placed vertically.

My first test of the MegaDipol was done well away from any potential noise sources, 170 meters away in fact. It was fed from a DX-Engineering coaxial cable. I later added a ground connection to the external unit. At my location, the added grounding did not change the noise floor or signal levels, but the general recommendation is to ground the antenna.
Later, I moved the antenna to a pole much closer to the house. The move from 170 meters away to 30 meters away did not change the noise floor or signal levels.

During the comparison, both antennas were connected to DX-Engineering 75-ohm coaxial cables. The longwire in addition had a matching transformer from DX-Engineering and was grounded on both ends. The MegaDipol was also grounded. The antennas were connected to two KiwiSDRs to facilitate accurate comparisons with identical hardware. Both feedlines had RF isolators inserted; The NTi GI 1000 galvanic isolator for the dipole, and the Wellbrook AFI-5030 for the longwire.
So, how does the MegaDipol compare to the longwire?


I was surprised to see the exceptional performance of the MegaDipol on Longwave. The lower down, the better. On my semi-local NRK 153 kHz, gain was typically 20 dB or more higher than the longwire, and the noise floor was a bit lower. So, all in all up to 25 dB better SNR. The difference decreased with higher frequency as my semi-local NDB “BV” on 399 kHz noted “only” a 10-12 dB difference in SNR.


While I had groundwave signals on LW for the comparison, summer daylight limited my comparisons to late evening skywave signals from the south – in the longwire’s lobe. Generally, the longwire does seem to have stronger signals, but the noise floor on the MegaDipol was lower. So, in effect, the difference was only slightly in favour of the longwire.

Shortwave, up to 7 MHz:

A bit like MW performance. The noise floor on the MegaDipol is lower, but so are signal levels. The net result isn’t very different, and one should note that the longwire’s length of 70 meters is very well matched with this part of the spectrum. A shorter longwire would likely not perform as well.

Shortwave, above 7 MHz:

The MegaDipol’s performance compared to the longwire increases with frequency. On a 31-metre band signal, the MegaDipol and the longwire were practically identical in SNR values. From there and up to 30 MHz, the MegaDipol performed increasingly better than the longwire. Skip on 27 MHz was mostly undetected on the longwire. A shorter longwire would probably fare a bit better than the long one, though.


The MegaDipol claims to hear up to 300 MHz. I compared the MegaDipol with a 3-element FM antenna on the FM and DAB frequency ranges. On FM, I only had one rather weak Finnish station to compare. It was fair on the FM antenna, not heard on the MegaDipol. On a 225 MHz DAB channel, both antennas heard the signal, although the FM antenna had a 10-dB better signal level. Noise levels were identical.


By mounting the two elements horizontally instead of vertically, it is possible to add directionality to enhance or reduce signals from chosen directions. Late in the test, NTi supplied me of 5-metre elements, one of which was placed semi-horizontally (sloping from 2.5 to 1.6 meters) off the direction of a wind park a few km away. The signature RFI of the Siemens wind turbines, increased noise levels from around 750 to 500 kHz, was reduced into general noise level when I pointed the horizontal element in its direction. The signals from 153 kHz and 399 kHz were also reduced a few dB, although a deeper null might have been possible if I had placed the direction of the horizontal element more precisely.


It’s a shame that I don’t have the Z1501 active whip anymore. It would have made a very interesting comparison. Since the Z1501 is out of the equation and considering previous comparisons I did with the ALA1530LF, the longwire and the Mini-Whip, I can safely say that the MegaDipol is an excellent overall performer, and the number one compact antenna I have tested so far.  The price tag may be discouraging for some. However, the Wellbrook loop checks in at GBP 225, and even the cheap longwire’s matching transformer is USD 60. So, small, active antennas usually come at a price. Longwires are cheap – if you have the property to fit one.

Tuesday, July 09, 2019

QSL: PJZ86 R. Curom, Willemstad, Curaçao, 860

"Z86" was heard with quite a good signal on my Perseus SDR at the Smøla island location in mid-February. My first-time logging of a station from Curaçao. I sent off a Facebook report at the time, and received a confirmation today.

Saturday, July 06, 2019

Rare Arctic E-skip on FM

A 30-minute, but strong Es opening yesterday brought 70 loggings from Denmark and Sweden. The opening was extremely narrow, comprising all heard stations within an 11 degrees bearing. Distances varied between 1065 and 1872 km.

I used a very modest 3-element FM antenna placed in the attic, connected to an SDRPlay RSP1A running at 8 MHz (6 MHz or so effective). I used SDR Console to decode and record IQ files to an external SSD for later playback.
Very narrow signal path. Log program:

If you want to look at the log, click this link.

Monday, June 24, 2019

Aerial View of my Radio Location

While enroute to Tromsø on a Wideroe DHC-8 200, we passed Kongsfjord at a perfect angle for taking a photo of my radio location. The arrowhead-like peninsula is named Veines, popular with birdwatchers and hikers. During WWII, the occupants set up a coast defence battery there as a part of Festung Norwegen.

My house is in the black circle. This summer I have an NTi MegaDipol set up in the red circle. The antenna is currently available on the ArcticSDR.

Friday, May 31, 2019

SDRs - Does the Enclosure Matter?

Traditional receivers, and most SDRs, have been encased in aluminium. Conventional wisdom says this is because they need to be protected from RFI. In later years though, some of the SDRPlay SDRs have had plastic enclosures, and the new Airspy HF+ Discovery is also said to be encased in plastic. It's been said that the RSP1A enclosure has an inner metal paint. That could be, but it looks like plastic, and it feels like plastic.

Anyway - aluminium enclosures are offered as a third-party solution to those who prefer metal, and I ordered one. When it arrived, I naturally had to remove the plastic enclosure, so I thought why not test the device with real signals, and without signals, in its original enclosure, the new metal enclosure, and bare? Just to find out how efficient they would be.

So I ran tests on FM and SW with 8 MHz bandwidths and compared spectra and waterfalls in SDR Console.

The results were...interesting. As a matter of fact, there was no difference whatsoever, even when the RSP1A board lay bare on the floor.

So, is conventional wisdom wrong? Not necessarily, my test is circumstantial evidence only. That said, my radio room has four PCs running, 5-6 SDRs and even a couple of rather dirty switching PSUs. So, lots of potential RFI. But the RSP1A was as immune bare as it was enclosed.

I'll keep the metal enclosure though, it's a bit smaller than the original plastic one, and looks much better. And there are other hazards to electrical equipment than RFI. Especially when they're on the floor!

Saturday, May 11, 2019

Some Candidates for the MW SDR DX-er

I’ve been a MW DX-er since my teens. Any other part of the radio spectrum is mostly tuned casually. Hence, I tend to evaluate my SDRs only by their MW performance.

A dedicated MW DX-er has some prerequisites for his or her receivers:
  • Sensitive enough to pull in signals in a low signal level environment.
  •  Robust enough to not overload easily when signal levels are high.
  • Access to software which can record and play back the entire MW band as efficiently as possible.

With the SDR being a “software defined radio”, it is true that software does define the radio experience. Software for the MW DX-er is worth a study of its own. However, at this stage, I thought it might be interesting to have a look at hardware that I have either tested myself, or that I think I know enough about to evaluate for MW DX-ing.

I even thought out a rather complex system for ranking the SDRs since they come in a large variety of price and performance levels. But the system relied on too many subjective factors, so for the time I settled for making an “Editor’s Choice” at the end of this article.

Software supplied with the hardware are listed in bold. Only Windows software versions are listed. Links to the SDR's home page and review pages where available.

RFSpace CloudIQ

9 kHz-56 MHz. Ethernet. External 5V, 0.5A. Max sampling rate: 1807 kHz (1500 kHz tuning range), good for MW. Sensitivity -111 dBm. Good front end. Two antenna ports, software switchable. USD 630. Out of stock – discontinued? Available as used but scarce. Software: Spectravue, SDR Console. Receiver link. Eham review.
RFSpace NetSDR

0-32 MHz. Ethernet. External 5V, 1.3A. Max sampling rate: 2 MHz (1600 kHz tuning range), good for MW. Sensitivity -102 dBm. VHF/UHF add-on board optional. USD 1450 in 2011. Discontinued, available as used but scarce.  Quite large footprint. Software: Spectravue, SDR Console. Receiver link.
Expert Electronics ColibriNANO

0-55 MHz. USB. USB power (USB 2.0 is ok). Max sampling rate: 3 MHz, 1536 kHz (1230 kHz tuning range) is good for MW. Sensitivity -90 dBm, noise floor is on the high side. EUR 300. Available. Smallest SDR. Software: ExpertSDR2 (no IQ file playback!), HDSDR. Receiver link.
Microtelecom Perseus

0-40 MHz, USB. External 5V, 0.75A. Max sampling rate 2 MHz (1600 kHz tuning range) is good for MW. Sensitivity -103dBm. Good front end. EUR 800 in 2019, few available. Discontinued? Available as used but scarce. Software: Perseus, HDSDR, SDR Console, Jaguar Pro/Jaguar Lite. Receiver link. Eham review.
Elad FDM-S2

9 kHz-52 MHz + FM and 135-160 MHz. USB. External 5V, 750 mA. Max sampling rate 6144 kHz, 1536 kHz-option (1230 kHz tuning range) is good for MW. Sensitivity -106dBm. EUR 525, available. Software: FDM-SW2, SDR Console. HDSDR. Receiver link. Eham review.
Winradio G31DDC

9 kHz-50 MHz. USB. External 12V power. Max sampling rate 2000 kHz, 1600 kHz tuning range is good for MW. Sensitivity -106dBm. Robust front end. GBP 700, available. Software: Winradio (IQ recordings will not store/display date and time! No IQ recording scheduler!), HDSDR (current dll only supports bandwidth up to 1000 kHz, 800 kHz tuning range). Receiver link. Eham review.
Winradio G33DDC

9 kHz-50 MHz. USB. External 12V power. Max sampling rate 6000 kHz, 1666.7 kHz sample rate gives a 1250 kHz tuning range which is good for MW, but 32-bit sampling gives double-sized IQ files compared to other SDRs. Sensitivity -110dBm. Very robust front end. GBP 1600, available. Software: Winradio, more options than the G31DDC software, HDSDR. Receiver link.

1 kHz-2 GHz. USB. USB power, 180 mA. Max sampling rate 10 MHz, 1536 kHz option (1230 kHz tuning range) is good for MW. Sensitivity -101dBm but drops off on LW. 2 MHz lowpass filter gives reasonable front end. DAB notch filter. USD 109, available. Software: SDRUno, HDSDR, SDR Console. Receiver link. Eham review.
(NEW! NOV-1-2019)

1 kHz-2 GHz. USB. USB power, 190 mA. Max sampling rate 10 MHz, 1536 kHz option (1230 kHz tuning range) is good for MW, also 600, 300 and 200 kHz spans useful for LW. Sensitivity similar to the RSP1A on MW, far better on LW. Three antenna ports, BNC port for DC to 200 MHz. 2 MHz and 500 kHz lowpass filters give good front end. DAB notch filter. USD 200. Available. Software: SDRUno, HDSDR, SDR Console (coming). Receiver info
Afedri SDR-Net

100 kHz-35 MHz. Ethernet (USB possible but too narrow IQ bandwidth). External 5V power, 370 mA. Max 2500 kHz sampling rate, 1333 kHz tuning range option is good for MW. Sensitivity -104dBm (overloads if gain is set too high), reasonable front end when gain is set low, otherwise poor. USD 260. Available. Software: HDSDR, SDR Console, various others. Receiver link.  Eham review.
SDRs not sampling the full MW band
Airspy HF+/ 
HF+ Discovery
9 kHz-31 MHz + 60-260 MHz. USB. USB power, less than 0.5A (USB 2.0 port is ok). Max tuning range is 660 kHz. Sensitivity -112dBm. Very robust front end. USD 200/170, available. Software: SDR#, HDSDR, SDR Console. Receiver link. Eham review.
Seeed KiwiSDR

10 kHz-30 MHz. Ethernet. External 5V, 1.2A. No IQ sampling. Up to 8 simultaneous channels. Sensitivity -102dBm. Good front end. Can be set up as server. USD 300, less during Massdrop campaigns. Available. Software: None. Runs on any HTML-5 browser, like Chrome, Edge, Firefox, Safari. Receiver link.
SDRs not reviewed
Early Elad and RFSpace SDRs. SDRs with upconverters. SDRPlay SDRs lacking a 2 MHz low pass filter. Any SDR over USD/EUR/GBP 2000. SDRs typically unavailable. SDRs with no, or limited MW coverage.
In the pipeline
Not much, as per May 2019:
Elad FDM-S3 seems to be in its final stage before launch. EUR 950. Two software-selectable antenna ports.
RFSpace CloudSDR – ETA at Q4/18 has been changed to Q4/19. USD 900? Will we see it?

My Picks:

Low price range/entry level: The SDRPlay RSPdx. It is quite sensitive on MW and LW, and may require some attenuation if the signal level is very high. 2 MHz  and 500 kHz low pass filter will help. Several software options. Can double as a sensitive FM and DAB receiver with 6-8 MHz effective bandwidth, depending on PC capacity. All for only USD 200. If your budget is lower, go for the SDRPlay RSP1A (USD 109).

Middle price range: Microtelecom Perseus. It is sensitive on MW and LW, good dynamic range and several third-party options including the bespoke Jaguar Pro/Jaguar Lite software which lifts the Perseus to the top of the sky. EUR 800 but limited stock, occasionally shows up on auction sites. A bit fiddly installation procedure. Others: Elad FDM-S2 (available, EUR 525), RFSpace CloudIQ (out of stock, maybe discontinued, USD 630). The Winradio G31DDC (available, GBP 700) will be a very good alternative if it gets full HDSDR support.

High price range: Winradio G33DDC. Very sensitive, and very good dynamic range. But a hefty price for the performance (GBP 1600), and limited software options which some may like and some will not. Others: RFSpace NetSDR, only available on the used market (USD 1450 new). Good sensitivity and dynamic range, several software options.

If IQ recording of the entire MW band is not important, consider the ethernet based KiwiSDR. No IQ recordings, but up to 8 simultaneous channels (USD 300). Audio recordings are possible from all channels. Or the USB based Airspy HF+ with excellent sensitivity and dynamic range. Several software options, 660 kHz alias-free IQ recording (USD 200).

But you will likely discover that IQ recording of the entire MW band is important.

Updated October 30, 2019.

Friday, May 10, 2019

A Second Look at the ColibriNANO SDR

I tested this SDR briefly back in 2017. I never got round to measure its sensitivity back then, and I also hoped that the manufacturer had addressed the many software issues I had. So almost two years after, I did another test. The original write-up (see links to the right) has been updated.

Spoiler: No, it's not worth €300.

Friday, May 03, 2019

A New Look at the Winradio G31DDC

I bought the G31DDC when it was brand new, thinking that this would be an excellent competitor to the Perseus SDR. Actually, it was an excellent receiver, installation goes in a breeze and it uses 12VDC external power, which is a lot easier to find in no-noise versions than 5VDC PSUs. Sensitivity is around -105 dBm, a tad better than the Perseus. But there were "issues"...

First, the Winradio GUI. It is, at least in my opinion, by no means optimised for efficient MW DX. And at the time there were no software alternatives. Second, and by far more important, the IQ files it recorded were not date- and timestamped! Absolutely disastrous, if you record a lot. And to top it all, no scheduler was available. What on earth were they thinking? Later, the G33DDC came along, with the recording issues solved, but still the old inefficient interface. And with the price doubled.

So, after a short while, my Winradio adventure ended.

I did notice later on that dynamic link libraries (dlls) were developed for use with HDSDR, but at that time I had parted with my G31 and G33.

Recently, related to a project I'm working on, I decided to take a new look at the G31DDC. So, I borrowed a unit (thanks TJ!) downloaded the HDSDR dll and tested the unit. Lo and behold, it is a good receiver!  The only downside is that the current dll only supports 1000 kHz sampling (800 kHz alias-free). So, the requirements for a good MW performer are still not met. But I believe that the dll could be revised to allow 1600 kHz alias-free sampling.

Because, with HDSDR, time- and datestamped files and scheduling is no problem at all.