Instead Of Dismantling An Old Radio And TV-tower

You can do this.

65 meters tall, this mini Eiffel-tower known in Berlevag as "Linken" ("the link") was erected in 1970 to house the NRK FM and TV repeaters. Nowadays it's used for mobile phone antennas and the owner Telenor had in fact thought of dismantling it. The municipality decided it could be put to better use, so they illuminated it with LED lamps. The link is a live cam, so you'll also get an impression of the weather in Berlevag (at the time of writing, a fresh breeze and snow showers).

A Weekend In Helsinki

Together with 14 ex-colleagues from the Municipality of Berlevag, I visited Helsinki last weekend. Not to anyone's surprise, I also met with several Finnish DX-ers. Jim Solatie and I had a splendid sushi lunch/dinner at Norisushi on Friday, and on Saturday I spent the better part of a full day with Antti Aaltonen, Håkan Sundman, Hannu Tikkanen and Mika Mäkelainen. It ended in the Belgian restaurant Belge, downtown Helsinki. I also had the chance to meet Jan-Erik Österholm and Hannu Niilekselä on the Helsinki airport on Sunday. They and Håkan were on their way to Lemmenjoki that day to take part in their LEM hostess Kristiina's funeral. Here are a few photos. Yes, we did eat and drink a lot.

Håkan, Hannu, Mika and Antti

From left: Yours truly, Mika, Hannu, Håkan. Photo: Antti Aaltonen

Part of Helsinki's sea front

The sushi plate at Norisushi. And a Sapporo beer to match

Bjarne, Antti, Mika, Håkan. Photo: Hannu Tikkanen

Norway's Two Remaining MW Stations Will Close

As per a press release from Norkring (in Norwegian only), the Vigra transmitter on 630 will close on June 30th, 2011, while the Røst transmitter on 675 will be left alive until December 31st, 2012 after only 13 years of service. This will leave Ingøy 153 as the only remaining AM transmitter on Norwegian mainland. Norkring's sole MW station left will be the 1 kW NRK relay at Longyearbyen, Svalbard (1485 kHz). I won't be surprised if its days are numbered too.

Thanks Svenn Martinsen for the info.

WGBW 1590 DX Test Summary

From OJ:

Summary from the WGBW test:

"The test was heard in the US and Canada. Longest distance 960 miles away.

Some of the audio files were spectacular, considering 700 miles away and an indoor ferrite antenna...

One fellow, did 43 minutes of monitoring, and got it solid for entire time from 460 miles away...

Most of the receptions were from Midwest and some Western states, a few from east coast (Wash DC area, West Virginia, Ohio)


One report was from 25 miles from WAKR in Akron, 1590, which really was outstanding. he simply nulled the station, and we were there!"

Thank you to Mark Heller at WGBW!

73 de OJ

KONG1 to KONG20 - Highlights

We've come a long way since the first KONG DX-pedition, in January 1997. KONG1 was a chilly affair. The house was in dire need of repairs, the toilet was outdoor with little protection from the wind, and the wind was strong. Temperatures were around -10 Celsius. Blowing snow with zero visibility forced my VW Golf out of the road three times (no damage done but the snowplough driver got tired of towing me back on the road again). The antennas (one? two?)  had no feed lines, no terminations and no splitters. We had one radio and one cassette recorder each. We soon found out that January was not a good month for travelling and DX-ing in this part of the world, so we decided that the next KONG would be in October. And so it has been since.

We've come a long way since 1997. Here are some highlights:

First coax feed line: KONG2, October 1997. Last coax feed line: KONG19. The KONG20 DX-pedition uses only 100 ohm lamp cord (twin-lead) feed lines.

First antenna splitter: KONG2. We needed to get rid of the one-antenna-per-direction-per-person chaos, so we got splitters. Amplified 1:4 splitters and even one 1:8 splitter have been in use ever since.

First Mini Disc recorder: KONG3, 1998. MDs were far superior to cassette recorders both in terms of capacity and ease of use. Especially useful was the pre-recording buffer featured on the Sony MZ-R50. We never had to lose an unexpected ID after that.

First real multi-receiver setup: KONG7, 2002. 11 receivers. With splitters, we could operate more receivers. And with MiniDisc recorders, it was easy to record, so the potential of hearing more stations increased. And we did hear more stations.

First PC recording: KONG8, October 2003. We had finally brought PCs to the site, and TotalRecorder proved to be an excellent replacement to MiniDisc, although the latter continued to be used. KONG8 also was the first KONG with a PC-controlled receiver, with Rolf's Winradio G303i.

First Real Pacific: KONG8. While Hawaii and 4QD 1548 in Australia were common catches, we hadn't heard anything else from the Pacific, until we heard Samoa 540, Kiribati 846 and Tonga 1017 that year. Subsequent KONGs would bring several more Pacific countries.

First (and only) catastrophic KONG: KONG9, November 2003. Arnstein couldn't take part in KONG8, so he and Ole Forr joined forces for an extra KONG in November, hoping to hear more Pacific. On the plane to Berlevag they read about the outbreak of the worst solar storm of that solar cycle... A total of three North American stations, and Peru-1470, were logged.

First KING crab: Probably KONG11, 2004. Records are a bit sketchy on this.

First New Zealand: KONG12, 2005. October 11 was the date of the first NZ catch in Norway. Several more NZ were logged by KONG13 a couple of weeks later. The past years have brought the number of New Zealand logs to well over 50.

Highest number of conventional receivers present in one KONG: 21, at KONG15, 2006. Seven IC-R75, three NRD-525, three Etón E1, two IC-746Pro; one each of IC-703, IC-7000, EK-895, HF-1000A, WJ-8712P and AR7030. A logistic nightmare.

First SDR: KONG17, 2007. A total of 10 RF Space SDR-IQs were present, in addition to 15 conventional receivers. In later KONGs, SDRs like the SDR-IQ, Perseus, and Excalibur have been the receivers of choice. Only one conventional receiver, the R75, is operational during KONG20.

KONG main crew:
Bjarne Mjelde (host, 19 KONGs), Arnstein Bue (15), Rolf Torvik (9), OJ Sagdahl (9).
KONG almost main crew: TJ Bråtveit (6)
KONG guests: Ole Forr (4), Tore B. Vik (3), Jan Alvestad (2), Tore Nilsen (2), Torgeir Woxen (1)
Other guests in Kongsfjord (from 1974 to date): Arvid Frøsland, Per Ingebretsen, Kai M. Mauseth, Dag Leraand, Geir Stokkeland, Torgeir Nyen, Antti Altonen, Håkan Sundman, Hannu Tikkanen, Jim Solatie.

KONG20 - Pictures

50-degrees beverage lamp cord feed line

50-degree beverage, view to the east

Power bay

Veines - The house

TJ (left) and Arnstein

Morning sun over the 340-beverage

50-degree beverage starting point with transformer

Bjarne's shack

Veines - The Sebulon bay

KONG20 - Midweek

Sorry for not having had the capacity to update the blog more often - I trust most of you will know about the excellent weblog found at Kongsfjord.no. Anyway, here are some observations.

Antennas - feed lines:
A few will have noticed that the beverage antennas have been replaced - and partly relocated - this year. See a post or two below for a bird's eye view. I have had all sorts of problems maintaining dry and noise-free coax feed lines. Even the sturdy RG-213 suffered wet and corroded braids.

So why not go for the simplest solution? The QDFA feed line was a simple lamp cord (100 ohm), and it worked very well. So I tested the new 310-degree beverage with the same feed line, and it worked excellently. Then both the 50- and the 340-degree beverages were equipped with surplus (probably because it is seasick green) lamp cord. From what we have experienced so far, lamp cord is an excellent coax replacement. Since it is 100 ohm, it will need a different transformer than the coax. They are of course easy to make, but I asked Wellbrook Communications to make me a few, which are weather-proof. I have used binding posts for the connections.

Antennas - wires:
The kingdom of the insulated copper wire has been toppled. The new king on the hill is insulated, steel-clad wire with a thin copper core and a tensile strength of 4000 Newton. This wire will not break. We are fairly certain that the wires have improved reception because of no poor joints (repairing the old copper wire led to more joints), actually no joints at all since they were more or less custom produced.

Antennas - QDFA:
This excellent performer was downed again on Friday. Most likely, the transistors got damaged from the sleet and hail storm on Thursday and Friday, probably from excessive static. A useful reminder to us that the QDFA phaser is still under development. Dallas Lankford will see if it is possible to add more protection to the circuitry. However, the Max-Gain fiberglass masts perform admirably. It will take a perfect storm to take them down.

Receivers:
We have Perseus, Excaliburs and SDR-IQs running here. They are all doing a splendid job, and there is no way of telling one from the other in terms of performance. Actually, what DX-ers should pay more attention to is the sound card. An SDR connected to a PC with a good sound card will in fact hear "more" than an SDR connected to a PC with a poor (such as an in-board solution) sound card. Identifying very weak and QRM'ed stations requires a good quality sound card.

Interestingly enough, TJ has an Icom R-75 standing in front of him. I have an Icom IC-703 standing in front of me, and Arnstein has a few Icom/NRDs packed away on the 1st floor. None of them have been in much use.

Weather:
After a warm start with up to 13 Celsius, October temperatures have become quite normal, which is from -1 to +5 Celsius, though mostly on the red side of the zero mark. A mix of rain and dry, sometimes even sunny. Quite windy at times. All in all a normal October week.

Communications:
It's only a few years ago the mobile phone coverage was limited to a poor signal at a single spot in one of the windows. We've come a long way since then, with full (albeit not 3G) mobile phone coverage from two networks, and reasonably fast internet access via a 450 MHz link. All receivers can be operated via remote if we so wish.

Food & drink:
As many will have noticed, a vital part of the KONG DX-peditions. Details found at OJ's weblog. However, our philosophy is to use a mix of high quality local ingredients together with the best that the rest of the world has to offer.

Pictures:
Oops, forgot. Coming up.

KONG20 - First Day

The KONG crew will land at 12:57 and will face +2 Celsius, 15-20 m/s (35-45 mph) northerly winds, rain and sleet showers. Luckily no antenna work seems to be necessary in the poor weather, as a steady stream of nice Pacific and North American stations have been logged via remote the last few weeks. Some highlights: 882 Southern Star, NZ;  567 RNZ; 909 Radio Live, NZ; 1224 AFN Kwajalein; 1240 XERO; 1230 KWIX; 1260 WSKO, KWEI. Let's hope the sun stays quiet the coming days.

More as it happens! Off to collect some king crab...

WGBW Two Rivers WI 1590 DX Test

From OJ Sagdahl, member of the KONG crew:

I heard WGBW Two Rivers WI 1590 in Kongsfjord one night in September 2009 while they were transmitting with full daytime power (1 kW) during some work on their equipment. President and General Manager Mark Heller responded with a kind confirmation and offered to try full power at nighttime again at an agreed time. This will now take place 16 October 2010 @ 12:00 am to 1:00 am CDT.

Mr. Heller will be putting together a program of music segments, which will attract attention. It will be one minute clips of Mickey Mouse Club March, Soupy Sales theme song (high frequency piano theme) and maybe some Les Paul too. There will be station identifications and announcements between the music segments. This will repeat for the entire hour. It will stand out!

Reception reports (email with MP3-file) can be sent to Mr. Mark Heller for verification: 

wgbw [at] lsol [dot] net

The Kongsfjord Antennas

Some may want to know which antennas are in use in Kongsfjord. The short version: Three beverages of various lengths, and one QDFA.

The longer version is that the 310 (225 meters) and 340 (330 meters) beverages (the latter won't be up until next weekend) are the two "North America" beverages. The 310 also pulls in signals from northern South America and Central America while the 340 is quite effective for Alaska and Hawaii as well. The 50 (500 meters) will pick up far east Asians and western Pacific.

The QDFA with its broad front lobe will pick up any of the above except South America, albeit with less gain, but it has a better f/b ratio than the others so it can hear stations the other antennas can't due to European interference.

The QDFA, 310 and 50 all have 100 ohm, "lamp cord" feed lines while the 340 is fed by an RG-213 coax.

September DX In Kongsfjord

September is when the season really starts, although rare stations before mid-September are - rare. The sun has behaved quite nicely with mostly low activity. The 20, 21, and 29 were good dates for North/Central America, Australia has been heard most days, and New Zealand is coming fast.
I am particularly pleased with the new, re-located 310 beverage. The low-MW logs from North America are all from the 310.
The regular stations are not listed as the list would be far too long. New logs in bold.

The Americas:


Freq Station Location
550 KBOW Butte, MT
560 KPQ Wenatchee, WA
570 CKGL Kitchener, ON
580 WTCM Traverse City, MI
600 WYEL Mayaguez, PR
600 WMT Cedar Rapids, IA
610 WIOD Miami, FL
610 CKTB St. Catharines, ON
620 KMNS Sioux City, IA
630 CFCO Chatham, ON
710 WDSM Superior, WI
920 KWAD Wadena, MN
930 KSEI Pocatello, ID
940 KYNO Fresno, CA
970 KQAQ Austin, MN
1020 KJJK Fergus, MN
1230 KTRF Thief River Falls, MN
1240 WJMC Rice Lake, WI
1400 WATW Ashland, WI
1410 KRWB Fosston, MN
1430 WBEV Beaver Dam, WI
1460 WHIC Rochester, NY

Asia/Pacific:
Sept 10 brought a few nice ones from Japan, such as 549 JOAP Naha, 684 JOAG Nagasaki and 1368 JOLG Tottori. The day after saw 630 KUAM Agana Guam (and heard a few times since). Many ABC stations, especially on low MW heard, 630 becoming something of a regular. The QDFA was the antenna in use. And on the 30, New Zealand finally formally logged with several Radio New Zealand and Newstalk ZB stations heard on the new, re-located 500-metre, 50-degree beverage.

Receivers used: The Microtelecom Perseus SDR and the Winradio G31DDC Excalibur SDR.

Excalibur Recording from Arctic Norway

A 1250 kHz, 150 second file was recorded at 0400Z this morning, roughly at sunrise. The spectrum covers the Mediumwave, and was recorded with an Excalibur SDR connected to a 250 meter long beverage at 310 degrees bearing. You will hear a mix of eastern and midwest stations from North America, with the odd northerly South America thrown in. The Europeans are mostly of modest strength, but UK, French and Spanish stations are quite strong (and the semi-local Russians).

You will also be able to "enjoy" my local Loran C station, situated 14 km away in the front lobe of the beverage.

The zipped file is 572 MB and can be downloaded here. Do not rename the file. Those who do not own an Excalibur can download the software from this site.

UPDATE! In case some were denied access to the file, here is the reason:

Looks like I need to find someone else to store my files.

The Perseus And Scheduled Recordings

After I found that Splinterware's System Scheduler worked flawlessly with the Excalibur SDR, I became increasingly dissatisfied with the way scheduled (and unattended) RF recordings worked with the Perseus SDR. So I began to experiment with the System Scheduler to see if it could run the Perseus as well.

The TOTH is a small gem of a scheduler, however too often it will fail to start a recording, or it will record only some of the scheduled recordings. Apparently, development was stopped before it had developed into a reliable software. Then there is the Perseus Record Scheduler (PRS) which I have tested briefly, but it is not ideal for recurring multiple recordings for many days (not to say weeks).

The Perseus and the Excalibur differ in two important aspects: Firstly, the Excalibur features keyboard shortcuts for just about any function. If you want to program the Perseus, you need to use mouse clicks to a specific part of the display (buttons, dialog boxes). So you can't move the GUI around on the display - if you do the mouse clicks won't work. Secondly, the Perseus prompts you for a file name prior to recording, while the Excalibur starts recording on the fly.

So, for the System Scheduler to work with the Perseus, you will have to program mouse clicks, and you will need to enter a file name in the dialog box. Fortunately, System Scheduler is powerful enough to let you define dates and/or times as file names, much the same way TOTH does.

A test this morning confirmed that the Perseus can indeed be scheduled by System Scheduler. So at the moment I have my PC recording top of the hours from both the Excalibur and the Perseus, using two events on the software.

The free version of System Scheduler is adequate for the task. The pro version gives you added versatility for USD 30. I haven't yet tested the pro version. By the way, the Help function is comprehensive, and most valuable for those (including me) who know nothing about programming.

There may be an abundance of software out there that do the same, and perhaps even better. I am however quite satisfied with what I got, so I feel no need to look further.

The Excalibur And Scheduled Recordings

As is known for those who've read about the Winradio Excalibur, the software lacks the ability to do scheduled DDC recordings. Which is puzzling, since their audio recording scheduler appears to be excellent.

Now, as many are aware of (myself not included), there is an abundance of programs offering scheduling of Windows software. John Smith, G8BUP, in a recent posting to a Winradio reflector pointed towards Splinterware's System Scheduler. I downloaded the free version of the program, and after a bit of investigation found it to be a very good companion to the Excalibur.

What it does, is to open the software, use the keyboard shortcuts for Start DDC Recording and Stop DDC Recording as part of the sendkey line and, if the user so wishes, closes Excalibur. These shortcuts are "Ctrl ¨" and "¨" respectively, and I didn't get them to work on the sendkey line. Luckily, you can define any of the 98 keyboard shortcuts to your own liking, so I chose "O" to start, and "V" to stop. The first "Wait"-command gives the Excalibur software time to "settle". I don't know if it is necessary or not, but better safe than sorry. 5000 is milliseconds, so this pause is 5 seconds.

The second "Wait"-command sets the length of the recording. In the illustration below it is set for 60 seconds. The third "Wait"-command gives the program 2 seconds to save the file until the Alt-F4 command is given for closing the Excalibur.

If you are doing more than one recording, closing the program is necessary, because otherwise the next scheduled recording will open another instance of Excalibur. I don't think 24 instances of the software will run very smoothly...

The scheduler itself has a large variety of options. The illustration below describes how I would use the scheduler for unattended full-hour and half-hour recordings.

As I mentioned, you can't choose the length of the recording in the scheduler, you need to do that in the sendkey line. The times refer to the PC clock, so they are local.

And of course, you need to prepare the Excalibur with the correct DDC bandwidth and the correct centre frequency. The DDC bandwidth can be changed with sendkeys, but I don't think the centre frequency can.

Update Sep 21: I have now made scheduled recordings over several nights, without any problems. This is indeed something you can use with the Excalibur. Thanks John for bringing this to my attention.

Pacific Stations Are Early This Year...

I was rather taken aback by noticing KUAM "Isla 63" Agana, Guam 630 totally alone on the frequency and a very nice signal at 1645 this afternoon. Usually, these islands will not show until October. Well, it's ok with me...

A Modest Evening Opening

At 2000 UTC, the QDFA antenna caught some NHK1 stations during their local ID slot, in addition to most of the common commercial Japan stations, and many Koreans. The listing below are those with a definite ID (updated 14 SEP):

Frequency	Station
549	NHK1 JOAP Naha
594	NHK1 JOAK Tokyo
612	NHK1 JOLK Fukuoka
666	NHK1 JOBK Osaka
684	NHK1 JOAG Nagasaki
729	NHK1 JOCK Nagoya
738	JORR RBC, Naha
1071	NHK1 JOFK Hiroshima
1224	NHK1 JOJK Kanazawa
1233	JOUR Nagasaki Hoso call letter id!
1368	NHK1 JOLG Tottori
1467	HLKN KBS Mogpo

And numerous of the more common stations from Korea and Japan not listed here. 

At 1800, several low-band Australians were heard according to OJ Sagdahl, but I wasn't listening at the time. Anyone eager to hear lots of Chinese, Japanese and Korean stations on MW can download the 1600 kHz Perseus file from this site. It is 415 MB in zipped mode. It will be available for a limited time only.

Arctic DX Summit 2010 Report

The ADXS 2010 has been a most pleasant experience, with friendly guests, good food, acceptable weather conditions but not much to listen to (except online from Smøla). Here are some photos from Friday and Saturday in random order. Please notice Jim Solatie's ice-cold swim in the Barents Sea (next land fall: Alaska). Photos: Mostly Jim and Bjarne

QDFA Version 3 - Initial Impressions

OJ Sagdahl and I finished the new "monster" QDFA yesterday. It didn't become quite as monstrous as we hoped, since weather considerations made us reduce the height somewhat, from a theoretical 21.5 ft to around 20. The loops are set up in a "house" pattern rather than a delta or flag, with two 12-ft masts on the loop's ends. The bottom vertical element is roughly 1 meter above ground.

The increased height and shape has provided us with a 5-6 dB extra gain, compared to versions 1 and 2. And most important: The Max-Gain masts are much more sturdy than the angling rods we used last year. But also a lot heavier, so they require good support and guys.

One interesting observation of version 3 is that the sensitivity appears to be identical throughout the MW band, while version 1 and 2 were noticeably less sensitive below 1000 kHz.

Arctic DX Summit 2010 - One Day Left!

Preparing for the upcoming Arctic DX Summit in Kongsfjord this weekend. 10 kg's of king crab is purchased, together with reindeer tenderloin, blueberry syrup, dandelion syrup, extra virgin olive oil with chili, and locally produced wild chives oil. Not to mention the wine, and the beer especially labelled for the occasion. The weather forecast is rather typical for early September.

On Sunday evening, OJ and I will attend the Opera Ball in Berlevåg, featuring some of the best singers and musicians in the kingdom.

Excalibur and DRM

DRM is part of the MF and HF bands today, albeit with a most uncertain future. Actually I bought a DRM license from Winradio back in 2007, to test with the SDR-IQ and later the Perseus. My trials were disappointing - I needed almost 20 dB SNR to decode, and another 5 dB to get stable reception. Not to mention the sound card problems. With the Excalibur I got decoding at around 15 dB SNR, and stable reception at around 18-19 dB. DRM with the Excalibur is very much plug and play, if you chose to install the DRM player when you installed the software and driver.

So, if you enjoy DRM, and you have a DRM license (or are willing to pay USD 50 to buy one), the Exalibr provides an excellent platfom. The illustration is from 13810 kHz at 1200 UTC.

Updated G31DDC Excalibur Review

I needed to do some cosmetic changes, but also some regarding content. Errors are corrected, and a further discussion regarding the Excalibur's DDC recording capability has been added. The download link is the same.

Excalibur DDC Recording Anomaly

I thought it was I who had done something wrong, some time ago when I didn't get a DDC recording to play back properly. I kept tuning up and down, but was still listening to the same signal.
Well, I hadn't. The thing is that there is - for no obvious reason - no reference or connection between the frequency range of the DDC recording and its playback. If you don't choose the "Insert freq" option when you record, you will not be able to play back the file with the correct frequency. And should you remember where you were during recording, you can "tune" only by clicking in the DDC or Demod spectrum - something that at best will be most inaccurate.

So, if you want to make a DDC recording, and play it back the way you play back a Perseus, SpectraVue or Winrad recording, you MUST choose "Insert freq". Now, I agree that in any case, it would be wise to put the center frequency of the DDC recording in the file name. But, when other vendors manage to get this connection right automatically, why can't Winradio? Who wants to make DDC recordings without being able to track the signals properly on playback? It is sort of ok when you're aware of it, but it does increase the risk of making a useless recording.

Excalibur: What Is Really Its Minimum Resolution Bandwidth?

There has been a discussion regarding the Excalibur's ability to accurately measure a station's excact frequency, down to the hertz. Well it can, provided it is correctly calibrated, but not on every DDC spectrum! In fact, for  nine of the 21 available DDC spectra the minimum resolution bandwidth of the Demodulation panel is 2 Hz, not 1 Hz. The best demodulation resolution is available for these DDC spectra: 20, 24, 32, 64, 125, 160, 320, 640, 800, 1250 and 1500 kHz.

When you record a DDC spectrum, it doesn't matter which RBW the Demodulation panel is set at. If it is set at, say 160 Hz during recording, you will still be able to see 1 Hz during playback.

A totally different subject: On July 23 we are experiencing a weather with a ferocity that is rare even during the stormy autumn months: Severe gale winds, heavy rainfalls and temperatures around 3 Celsius. A few days ago we enjoyed 23 Celsius...

Preliminary Review: The Winradio G31DDC Excalibur

I have uploaded a pdf with my initial impressions of the Excalibur SDR. It hasn't yet been tested in real DX situations, so it's bit early to be conclusive. However, it is indeed an interesting receiver and should be a good choice if you want to buy an SDR. Or if you want to buy another SDR...

Download from here.

Excalibur's Readout Accuracy

Many DX-ers (MW DX-ers in particular) are concerned about the Excalibur's ability to show the exact frequency down to the hertz. While most SWLs will be indifferent about this, quite a few are monitoring a station's offset from it nominal frequency, and it is also helpful for tentatively ID-ing stations (assuming their offset is reasonably constant).

By zooming in the demodulator panel and by using 1 Hz RBW, monitoring offsets is indeed possible, as illustrated above. Two stations are visible (and audible) on this screen dump from 999 kHz, a Russian-speaking station on 999.008, and a presumed Arabian station on 998.992 kHz. Prior to monitoring, I calibrated the Excalibur using a tone from the signal generator on 1000 kHz. Of course, in order to monitor offsets in the range of 1-5 Hz, the readout must be exact.

Excalibur Sensitivity Measurements

When the Perseus and the Excalibur are monitored side by side, the Excalibur's S-meter consistently reads 6-8 dB lower than the Perseus. One might be tempted to believe that the sensitivity is lower. Well that is not the case. More on that later.

I found these sensitivity measurements using a signal generator with 400 Hz tone and 30 % modulation:

200 kHz: -103 dBm

300 kHz: -102 dBm

600 kHz: -106 dBm

1000 kHz: -107 dBm

1500 kHz: -107 dBm

5000 kHz: -107 dBm

10000 kHz: -107 dBm

20000 kHz: -106 dBm

In terms of sheer numbers, the Excalibur is the most sensitive SDR I have measured, with a good 1uV sensitivity throughout most of the MW and SW spectrum.

So why does the S-meter read much lower than the Perseus? It is apparently not calibrated. When I fed a -107 dBm signal from the signal generator to the Excalibur, the S-meter read -115 dBm. This is roughly consistent with the difference between the Perseus and Excalibur S-meters.

Update July 20: Martin Kent at Winradio suggested that there might be a bug in version 1.06 that caused the erroneous signal level readout, and asked me to check the signal level with version 1.10. Indeed, the difference between the signal generator at Excalibur was reduced to 3 dB. My signal generator may not be 100 % calibrated, so I have no way of saying if the signal generator or the Excalibur was correct. Or any of them.

Now, for those who want to compare Perseus and Excalibur recordings, I have uploaded two 1 MHz recordings with 6120 kHz as center frequency. The recordings contain a lot of static due to nearby thundershowers, giving their AGCs something to work on. The signal levels aren't too high, with the exception of semi-local Murmansk 5930. This should be a good opportunity to compare selectivity.

(Update Aug 6: The download files are deleted due to server limitations. If you want to check out an Excalibur MW file, please download from here)

Excalibur Has Arrived

Got it on Wednesday evening, July 7th. I ordered it with Waters & Stanton on June 20nd, and received confirmation on same-day despatch. However they didn't send it until I made an inquiry nine days later. The question why it took so long remained unanswered. Anyway, I was lucky enough to be able to buy from the first batch of receivers sent to Europe. Thanks Tracey Gardner for alerting me.

The Excalibur came with a 12VDC linear power supply, a proprietary USB cable and an SMA-to-BNC adapter, rather fragile in appearance in fact. Surely, nobody uses SMA connectors for their HF receivers??? A comprehensive (107 pages in fact) user's guide, based on the Excalibur software help function was also enclosed.

The hardware is more or less identical to the other Winradio receivers. The footprint roughly equals that of the Perseus SDR, but slightly taller.

As I learn more about the receiver I will post some theme-based impressions on the blog. More as it happens.

Playing With The Excalibur Demo Software

The Excalibur software is downloadable from Winradio's download pages, working in a demo mode as long as the receiver has not been installed. It has a test signal on 15 MHz, as you can see from the screendump.

The initial impression of the GUI is quite good, although they try to put a lot of information into limited space. A good thing is that the program window is resizeable and that several "skins" are available.

The RF recording feature suffers from the same problem as the Perseus: No scheduled recordings. Third party software solved the problem for the Perseus, and I hope that a Winradio plugin, or a software update, will solve the problem for the Excalibur too. There is in fact a very able scheduler in the program, but it only handles audio recordings.

There are some really nice features once you dig a bit deeper into the software. I hope to see the receiver some time next week.

Excalibur Ships!

While there have been no updates on winradio.com regarding the Excalibur (as of June 20 at 1945 UTC), Waters and Stanton announced that the radio arrived there on June 18 and they are taking orders. They have taken mine. Thanks Tracey Gardner for alerting me.

QDFA Project Version 3

Those who followed this blog last season know that we were very satisfied with the performance of the QDFA. There were however some problems:

1. The amplifier transistors blew due to static discharge. Proper surge arrestors were fitted by Dallas Lankford, and the QDFA v. 2 was up late November.

2. Another problem, probably related to static build-up, caused the transistors not to blow but produce excessive noise. The only explanation we can find is that replacing the battery in cold, dry weather caused the problem. Another fix was needed, and the coming season we will supply power to the QDFA box from within the house. Hopefully, the extra cable will not compromise the nulling properties of the QDFA.

3. The cheap angling rods, while surprisingly weatherproof, did not survive the winter entirely intact. One of them failed in January, and another in April. So we decided we need proper supports, and found them at Max-Gain Systems Inc. These are extremely sturdy fiberglass rods, fastened not by friction but with clamps. We got four 21-ft center supports, and eight 12-ft end supports. This allows us to double the area of each loop, giving us another 6 dB of gain. The visual appearance of the loops will be a "house" instead of the common "delta".

The QDFA v. 3 will be up and running as the Arctic DX Summit starts, early September.

Arctic DX Summit 2010

From Sep 3 to Sep 5, Kongsfjord will be the venue for the Arctic DX Summit. Over the last few years, the Kongsfjord (KONG) and Lemmenjoki (LEM) crews have established a closer collaboration with regards to condx alerts, DX openings, loggings, equipment and QSLs. So it's about time we meet!

OJ Sagdahl and Bjarne Mjelde (host) will meet with Finnish DX-ers Jim Solatie, Håkan Sundman, Hannu Tikkanen and Antti Aaltonen. We will test the novel QDFA antenna design, the new Winradio Excalibur SDR, discuss various facets of the DX hobby, eat Norwegian seafood (and surely more than that) and drink good wines (and surely more than that).

Our intention is that the Arctic DX Summit will evolve into an annual event.

EAC R-390A Spring Test

My EAC s/n 204 R-390A isn't used for DX anymore, but I fire it up now and then to make sure that it works properly. And it always does. This time, I connected a pair of Logitech active speakers to the audio and line out connections.

Using the Lankford-designed manual AM sync I can enjoy distortion-free reception with the R-390A. It is enabled by switching the BFO switch on. Tune the Pitch control to obtain zero beat. At the time I took the photo, I was tuned to Radio Romania's German service. The radio on top is a 1950's Radionette. Works perfectly too, except there's no light in the magic eye.

Micronesia Air Checks

the Federated States of Micronesia is an elusive country for MW enthusiasts in Europe, to my knowledge the only confirmed European reception is V6AJ 1503 kHz in Kongsfjord in 2007. Paul Walker is an announcer at Monster Radio 1150 WGGH Marion IL, and he has taken a special interest in the Micronesia radio scene. A result of this is a collection of air checks from V6AI 1494 kHz, relaying 88.1 FM using a "KUTE" moniker. Paul generously offered me to share these air checks with other DX-ers. They are around 45 minutes each and in MP3 format.

Air check 1

Air check 2

Air check 3

Air check 4

Air check 5

Enjoy!

WOC Davenport IA 1420 Photos

WOC is a very common guest, especially in northern Scandinavia, but they've been heard in large parts of Europe this season. It's many years since I received a verification from the station. Yesterday, veteran engineer Jon Book at WOC emailed me some photos from the station, including one KMXG-FM tower photo. Breathtaking! All pictures are (c) Jon Book.

Jon also contributes to Captain Ernie's Showboat, a treasure vault of radio history from the Quad Cities.

Winradio Excalibur Soon Out?

According to the latest info I've received from Winradio, production has now started and they are awaiting CE certification.

Interestingly enough, the preliminary spec sheet has been revised. Minimum selectivity is now 10 Hz instead of 50, the resolution bandwidth within a DDC spectrum is now 1 Hz and not 15, and most important for me, sensitivity figures have been upgraded from a mediocre -94 dBm to a more acceptable -101 dBm (AM, 30 % modulation).

"It will be on sale shortly", Winradio claims.

Its GUI has been slightly changed too, as can be seen on the pictures above. Above is the January version of the GUI, below is the current one. Not bad at all. The displays are fully zoomable and the DDC can be displayed in a separate window.

Another QDFA Antenna Success

Those of you who are still not convinced that the QDFA is a superior antenna for MW should read Walt Salmaniw's report from Haida Gwaii, British Columbia, Canada.

So what are you waiting for?