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...