And Nothing Much Happened On Sunday...

Conditions were mostly absent on Sunday morning, so I decided to make an early return to Vadsø. An SMS from Mika confirmed that conditions towards Asia later that day weren't very exciting.

Anyway, the reason for going to Kongsfjord in the first place was preparations for the upcoming KONG22 DXpedition, which starts with the arrivals of OJ Sagdahl, TJ Bråtveit and Ole Forr on Saturday. There is some logistics involved in preparing for these events, and with the nearest grocery store 32 km away there is, to quote any NatGeo TV program, "no room for error". At least not the way we cook...

I'm going back to Kongsfjord Friday afternoon.

Saturday's DX - And Then Suddenly Nothing Happened

A very nice start actually, as at 1100 UTC most frequencies housing Japan's broadcasters were speaking Japanese, and I also noted some interesting stations from China, such as Nei Menggu RGD on 1584. I was just waiting for New Zealand to become audible, when suddenly someone cut the antenna. Or someone hadn't but it sounded like that. Dead quiet, except my semi-local Russians. When conditions slowy recovered a few hours later it was typically auroral with Iran dominating almost every frequency they're listed on. One's been uploaded and is available in the Audio Files section.

Before the DX started I made a brief trip to Berlevåg to see old aquaintances. On the way back I took the picture below. My QTH is just where the sun focuses its rays. Incidentally, maybe.

We'll see what the night brings. I'm in contact with Mika Mäkeläinen in Aihkiniemi via SMS, comprising the Arctic Early Warning Radio Alarm System. Or something to that effect.

Saturday Oct 6 Report

Not much to report, really. The plasma blob on the sun yesterday certainly had its impact and conditions went quite auroral with few if any North American stations audible. Some stations from Brazil and Argentina had ok signal levels but nothing really "DX-able". Instead I did some more comparisons between the omnidirectional Mini-Whip active antenna and my directive beverages. This time I had connected a Kiwa 10 dB preamp to the Mini-Whip feedline to put the antennas on equal terms with regard to gain.

The Mini-Whip fares quite well when signals are above a certain level. Weak but audible X-band stations, such as AM Restauración, Argentina on 1630 isn't heard on the Mini-Whip, while the 50-degree beverage backlobe hears it quite well. When it comes to monitoring more powerful stations in-band, the difference is much less pronounced.

This 20-second recording of Buenos Aires on 1270 should illustrate my point. The first 10 seconds is from the Mini-Whip, the last 10 from the 50-degree beverage (pardon the unintended difference in audio gain). While the latter is definitely stronger, the Mini-Whip does a very decent job. Add to the equation that the NetSDR which hosted the Mini-Whip is a few dB less sensitive than the Afedri SDR-Net which was connected to the beverage.

I experienced roughly the same difference when I compared with Brazil 4885 kHz.

During the day I will ground the Mini Whip feed line to see if there is any difference in noise levels.
UPDATE: After grounding the coax braid, there was no difference. The SDR-Radio waterfall was identical before and after the grounding, so I presume that the noise level is as good as it gets.

Misty but relatively calm, 8 degrees Celsius at 7 am local, this is in the "Warm" category for October and 71 degrees north.

Update: Sensitivity Measurements

Some time ago I published some sensitivity measurements from receivers I have owned or borrowed. It's been a while since the last update, but here it is.

The Mini-Whip - Erecting It And Initial Results

Although I have used the Mini-Whip before, this is the first time I've erected it properly, and made a systematic test and comparison with my other antennas.

I decided to mount the Mini-Whip to a 21-ft telescoping fiber glass mast from Max-Gain. The mast costs a lot more than the antenna, but is extremely robust. The elements are hollow, allowing the feed line to run inside the mast. I secured the antenna with Coax-Seal at the top.

 Of course, the fiber glass mast needs a support, so I basically used what was at hand.

Identical masts have been in use for two winters in the QDFA array, and I don't expect it to collapse or break.

At the bottom of the mast I made extra room for the feedline to avoid stress and potential damage.

On to the tests! Comparing a small, unidirectional active antenna with directive beverages from 225 to 500 meters long is a bit like comparing a family sedan with a racing car - and half expecting the former to win. And just so it's said: On Shortwave the Mini-Whip outperformed all my other antennas with a comfortable margin. But what about Mediumwave?

The first test array was comparing signal levels on the groundwave stations audible here. I compared the Mini-Whip with the QDFA phased array, and the 310 degrees beverage (225 meters). The stations were: 153 kHz NRK Ingøy, 399 kHz NDB "BV", 657 kHz Radio Rossii Murmansk, 675 kHz NRK Røst, 1134 kHz Radio Mayak Murmansk, 1449 kHz Radio Mayak Monchegorsk and 1521 kHz Radio Mayak Zapolyarny.

And this is how it turned out:

Frequency	Mini-Whip	QDFA	310 beverage
153	-80 dBm	-61 dBm	-70 dBm
399	-82 dBm	-60 dBm	-57 dBm
657	-73 dBm	-72 dBm	-56 dBm
675	-112 dBm	-103 dBm	-96 dBm
1134	-83 dBm	-71 dBm	-63 dBm
1449	-79 dBm	-75 dBm	-70 dBm
1521	-72 dBm	-69 dBm	-60 dBm

10-20 dB behind the 310 isn't bad at all, and almost equal levels with the QDFA at times. I did expect it to fare better on LW though, given its reputation as an excellent antenna for NDB hunting.

One important factor I have missed in this test however is that the other antennas have preamps in front, while the Mini-Whip has none (except the one in the Power Feed Unit).

Because of this, I did a quick measurement of each antenna's noise floor at current conditions. The Mini-Whip measured -112 dBm (1200 kHz, daylight), while the beverages were around -118 dBm. All measurements were done with the G33DDC Excalibur Pro.

Skywave tests have been postponed to a later weekend.

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.