Right In The Middle Of The Aurora...

This doesn't look too promising. In fact, the MW was all Arabic and Farsi this evening - with a couple of exceptions, like this one from Down Under. We'll see what happens during the night and tomorrow morning.

Weekend DX - Not Much More To Tell

Last night's DX - or should I say this morning's DX - was uneventful. Only the usual stations were heard during the one full hour I recorded, and the level of European stations were surprisingly high so a lot of frequencies were pested with noise. Iowa/North Dakota/Wisconsin stations were dominating, indicative of disturbed propagation.

Exceptional rain fall last night after an exceptionally mild September day - up to 13 Celsius. Still nice and mild with 9 Celsius, and dry.

Weekend DX - And How Does The Afedri SDR-net Cope?

I drove to Kongsfjord Friday afternoon to do further tests of the 340 (alas, jury's still out and I don't know when it will return - if at all), and do some DX. Australia's been going quite well for several days, however for some reason only South Australia. The rest of the country is mostly absent, even the most common of them all, 4QD-1548. X-band has been exceptionally quiet.

Radio National 729 and 5AN 891, both in Adelaide, have had very nice signals, such as this one recorded at 17:30 UTC on 729 kHz. It was recorded off the Afedri SDR-net.

Conditions towards North America last night were mediocre, but enough to make a comparison of the dual 340 beverage, compared to two single 340's. A dual beverage has definitely more gain than a single one - average measurements suggests 5-6 dB or one S-unit. But it is more susceptible to Loran C noise too, and the F/B ratio has not been improved. It was impossible to measure if the front lobe had become narrower, which is basically the idea behind the dual beverage.

Some time ago I promised to get back to the Afedri SDR-net's capacity as a MW DX receiver. Could it really stack up with the much more expensive SDRs like the G33DDC, Perseus and NetSDR? Well yes it can. If I pay a bit attention to its somewhat fragile front-end, and reduce the VGA gain when necessary, there isn't much the other SDRs can do that the Afedri can't. It's a keeper. It has been appointed official DU hunter, and is connected to the 500 meter 50 degrees beverage.

I'm writing this Saturday evening, hoping to hear some North Americans tomorrow morning. Next weekend will see the inauguration of Bakker's MINI-whip to the MAX-Gain (21 ft) mast which was ordered a few days ago.

While waiting, I'm enjoying "Luftgitar" (Air Guitar in English), a rock program  on RAS-2 - via satellite of course.

Season Preparations With OJ - Final Day

Sunday was typical autumn - brisk winds and showers, and temperatures around 6-7 Celsius. Luckily, most of our outdoor work was done by then.

Testing the dual parallel beverage wasn't easy. We needed signals from many directions to be able to determine if it had other - and hopefully better - properties than a standard beverage. Stable MW signals are mostly only found to the southeast (Kola peninsula), so we settled for a suite of NDBs in the 300-400 kHz range.

The tests were inconclusive. We understand that in order for a dual parallel beverage to work properly, the two beverages need to be identical. Terrain conditions prevented this. More surprising though, is that the eastern leg provided significantly better gain than the western leg, from 2 dB up to around 5 dB. So in electrical terms, they weren't identical.

The two connected together via the DX Engineering Combiner did add 5-6 dB of gain over the single eastern beverage. Unfortunately, this level of gain also a substantial increase in broadband Loran C noise. This seems to be the limiting factor, despite using a 75 dB 100 kHz notch filter and a high pass filter for protection.

I will continue testing the 340 dual parallel beverage next weekend, weather permitting, hopefully with skywave signals. We will then find out if we will keep the dual beverage (not very likely), or which of the eastern or western single beverages will be kept.

We drove to Vadsø in the afternoon. The weekend's last dinner was woked fillets of chicken with leak, paprika, red chili and jasmine rice with curry. Lotsa curry. The remaining wine bottle from the weekend was a 2008 Rossodiverzella. Very good. For dessert: Mövenpick vanilla ice cream with chocolate syrup or raspberry sauce.

Conditions improved during Sunday, and in the evening OJ logged two most wanted Australians on 729 and 891 kHz on the 50 degrees beverage.

OJ left Vadsø at 0415 UTC on Monday morning, and I'm preparing for work with a moderately aching back...

Season Preparations With OJ - Third Day

Saturday was relatively calm, cloudy most of the day but sunny and nice towards the afternoon. The dual, parallel 340 degree beverage was finally completed, and briefly tested.

The QDFA refurb was completed as well, and performed to specs when we tested it. This is what we did: First we connected loop no 1 directly to the feed line while monitoring two groundwave stations from Murmansk; 657 and 1134. Those stations are located at 142 degrees, or roughly South-East of here. Although not in the QDFA's deepest null, the loop should attenuate their signals somewhat. 

After testing loop no 1 we removed it and connected loop no 2 etc. When we had recorded the signal levels for each individual loop, we connected all loops to the phaser and feed line.

The individual loops received 657 kHz at an average level of -70.7 dBm (ranging from -69.3 to -72.4). The QDFA received 657 at -88 dBm, giving roughly 17 dB of attenuation.

1134 kHz levels were - 85.6 dBm in average, ranging from -83 to -87.5. The QDFA level was -94 dBm, or 8.4 dBm attenuation. We are quite satisfied with this.

It should be mentioned too, that the phaser box escaped the previous, rather harsh winter, unscathed. Everything appears to be working, thanks to the continuing modification work carried out by Dallas Lankford. It now appears to have passed the weather test of one of the worst habitable winter climates of the world. It is also worth mentioning that the fiber glass masts from Max-Gain are exceptionally robust.

Our backs were aching after two challenging days on the antenna field, but in the evening we could finally enjoy reindeer sirloins with mashed potatoes and woked leak, red onions, red chili and (red) tomatoes. A most delicious Australian red wine was enjoyed with the meat, 2010 Miss Harry bought in Finland (and recommended by Antti Altonen). It's in fact not available in Norway.

Dessert: Jelly with artificial strawberry taste, and (real) vanilla custard.

Season Preparations with OJ - Second Day

Friday was a bit windy but dry and even a bit of sun, so all in all a nice day for antenna maintenance.

The QDFA was in need a total refurbishment, except the superb Max-Gain supports. New antenna wires were fitted, resistors replaced, transformers reworked and feed lines repaired. The feed lines will be set up today, allowing us to test the QDFA with a fresh battery.

The dual, parallel 340 degree beverage feed line system was built, including transformers, isolators and a combiner, including grounding. The western part of the beverage was set up yesterday, the eastern part will be erected today.

We also erected the "old" 310 degree beverage. It apparently works very well indeed, since with the current auroral conditions stations from the Middle East were very strong to its back lobe.

After 8 hours more or less outdoor, walking, lifting and carrying (heavy loads) most of the time, we were quite exhausted in the evening. We did have enough energy though to make ourselves woked salmon with carbonara. We enjoyed Calles Riesling with the salmon, and we even found a bottle of port wine left over from last year's KONG21.

No transatlantic signals during the night.

Saturday morning is overcast but dry and relatively calm, and 6 degrees Celsius. It is soon time to get to work...

Season Preparations With OJ - First Day

OJ Sagdahl arrived to Vadso by plane on Thursday, and we drove the 170 km to Kongsfjord in the afternoon in rainy and windy conditions. Our goal is to get all or most of the antennas out, including the new dual parallel 340 degrees phased beverage. The 50 degrees beverage was erected last weekend and is the only one up at the moment.

Some Japanese stations were heard in the afternoon, but all of a sudden everything disappeared - the ionosphere is obviously still "shaken" after the CME and proton event a few days ago. Later in the evening we heard a few Filipinos.

Prior to and half an hour after sunrise this Friday morning, South America had decent signals on the back lobe of the 50 degrees beverage. Mostly Brazil, and a few from Argentina and Uruguay. Such as Radio Monte Carlo, Montevideo on 930.

As usual when DX-ers come together in Kongsfjord, good food is prepared and good wine is consumed. Thursday evening we put together a reindeer stew, comprised of thin reindeer shavings, red onion, red chili and mashed potatoes. A 2006 Weinert Carrascal proved to be a superb companion. We had chocolate pudding with vanilla custard for dessert, and we finished off with a glass of Disaronno. Or maybe two.

Photos will follow.

A Cool Recorder For The Afedri SDR-net

All the SDR software packages supporting the Afedri SDR-net can do RF recordings, and to a varying degree scheduling is possible too. But if the main purpose is recording and not live listening, you might find yourself wanting just a simple recorder. Well, the Perseus SDR has its Mestor, and now the Afedri SDR-net has its Afedrec! It was developed by Vasiliy Gokoyev and made available through the Afedri SDR-net Yahoo reflector.

Afedrec is a character based application, and at that it takes some time to put all the parameters in (and to avoid the syntax errors). Looking for a way to make a one-click recording, I turned to my old friend System Scheduler which had proved to be a very reliable application for doing G31DDC scheduled recordings.

Afedrec in the CMD window. Each dot represents 10 MB of data.

This turned out to be a very good idea indeed. Programming System Scheduler to make recordings of various lengths (or various center frequencies or various sample rates) is quite straightforward. When I open System Scheduler, I can select the recording I want to make, and select the Play button. Of course, I can also set up automated scheduled recordings.

Programming the Afedrec

When Afedrec is recording, you can play back previous recordings with Spectravue. Apparently this is not possible with SDR-Radio, because it holds a UDP socket open and by default the second connection is not allowed.

Afedrec is extremely gentle on the CPU. On my i5-2310 2.9 GHz system, the CPU load when running at 1333 kHz sample rate is 1 % or less, while SDR-Radio and Spectravue both use around 7 % CPU. Afedrec recordings can be played back on SDR-Radio, Spectravue, Winrad and HDSDR.

If you want to do scheduled recordings with the Afedri SDR-net, or a one-off recording without monitoring (for instance a full hour recording), the Afedrec/System Scheduler combination is hard to beat.

Preparations For The Upcoming Season

With the second weekend without the midnight sun, evenings are already becoming darker. Although it will still be three weeks until we can expect to hear any DX, preparations start early.

We are always experimenting with new antennas. This year we will test a replacement to the 340-degree beverage, namely a staggered beverage in roughly the same direction. Otherwise, the antenna farm will not change much.

Most of the time was spent indoor though, painting walls that haven't seen new paint since the mid-70's. The photos below were taken just after sunset on Friday. It is the northern side of the Veines peninsula. This is quickly eroding (in geological perspective) sand stone.

Take Your SDR To The Beach

Getting away from man-made noise has become increasingly important for DX-ers - and increasingly difficult. Going to the seaside or into the mountains can provide excellent opportunities for DX. But you need power! A laptop can last a night if one brings along an extra battery. However, feeding a 5V SDR from the laptop will either not work at all (too much current load), or it will drain the laptop's battery rather fast.

Battery packs have been around for a while. Some of them are quite powerful. After a quick search on Ebay I ordered a 11200 mAh battery pack which has two 5V outputs, rated at 1A and 2.1A. It came with a variety of adapters and connectors so one should have no problems to charge any mobile phone on the market today.

No, you can't power an R-390A with it... 

Left and right: 5V outputs. Middle above: DC input. Middle below: LED lamp

But the battery pack can do more than to give extra juice to demanding smartphones. The one I bought can power two SDRs! The Perseus draws around 750 mA while the Afedri has a modest 390 mA demand. At least in theory, this battery pack will power the Perseus almost 15 hours, and the Afedri almost 29 hours.

I don't know how much current is necessary to run the NetSDR - probably a bit more than the Perseus but less than 1A since I could feed all three of my 5V SDRs from the 1A output.

Before connecting the battery pack to my SDRs I checked the voltage of the DC outputs. I was somewhat surprised to see that they weren't quite the same. The 2.1A output measured 4.95V which is very good, while the 1A output measured 5.35V. That's a bit on the high side. Although all three SDRs worked with 5.35V when I tested them, I have decided not to push my luck. I'll stick to the 2.1A, 4.95V output.

Otherwise, the battery pack is a nice looking, small and light device.  The enclosure had FCC and CE logos on it, hopefully for a reason, and the price was USD 40 including air mail shipping from China. And they've even built a LED torch light into it. So you can search for the car keys you dropped when you erected the antenna.

Update Aug 11:
I let the battery pack feed the Perseus for most of yesterday, until only the last of the indicator LEDs were lit. How much juice was left I don't know. I was expecting (or fearing) that voltage would drop as the battery drained. However, the voltage reading of the 1A output was identical (4.95V) to the voltage when the battery was fully charged. So apparently, the battery is able to keep voltage stable for a very long time.

Thank you Takashi Kuroda for making me aware of these devices.