Monday, April 27, 2009

Another Kongsfjord Perseus File

This Perseus file is recorded on Jan 10, 2009 at 1430 UTC. This is rather late in the day, with  the eastern half of North America already sunlit, but some of the more dominant west coast MW stations can still be heard, together with several Pacific Canadian NDBs in the LW band. The half hour is full hour in India and Iran, and there should be a few stations from that region as well. Iran 702 and India 1566 were certainly very strong.

Saturday, April 18, 2009

SpectraVue Beta Reads 1600 kHz Perseus Files!

With the exception of Winrad, SDR software has been proprietary to the hardware. SpectraVue for the RF Space SDRs, and Perseus for the - you guessed it - Perseus SDR. Finnish DX-er Tarmo Kontro alerted me about SpectraVue 3.0 beta 19 which is in fact able to read 1600 kHz Perseus files! The beta 16 could read 800 kHz Perseus files, but I was hoping Moetronix would develop Perseus support further. And indeed that happened! Above is an image of SV 3.0 beta 19 running a 1600 kHz Perseus file from October 2008 (incidentally just as I heard a KVXR ID on 1280). The software, although in beta, appeared to be very stable.

Now, this seemed to be good news also for other users. Netbook owners! The Perseus software is a fixed window 1024x648 (?) pixels, while most netbooks only run 1024x620, or even 1024x578 pixels. With 620 lines, running Perseus is sort of OK if you move the window a bit upwards and allow the task bar to be hidden. But SpectraVue is scaleable, leaving you in better control over the task bar and the desktop. I tested a 1600 kHz file on my MSI Wind running at turbo mode (1.98 GHz instead of the standard 1.6 GHz), and it was running very smooth, although with a high (90%) CPU load. As was pointed out by Anders Hultqvist though, a "chopped" Perseus file (using Chuck Hutton's excellent "WavChopper" utility) will not play at the utility's current state.

SpectraVue 3.0 beta 19 is [Update: Was!] available from this site. Only the latest beta is downloadable, and there is no guarantee that following betas will support Perseus. Also, I am quoting the usual caveat: If you are not comfortable un-zipping and dealing with bugs and program crashes PLEASE do not download these Beta versions as they are continually changing and can be unstable or non-working.

Update: Well, Spectravue was "open" just for so long. The current beta on the link above is 20, which has a new limitation: "Limit Perseus File playback to SDR-xx owners". So there you go. No SDR-IQ or SDR-14, no Perseus playback. This posting has been changed accordingly.
Update: No, I will not distribute the beta 19. No more requests please.

Friday, April 17, 2009

New Kongsfjord Perseus File

Since the first Kongsfjord Perseus file was downloaded 188 times before I removed it, many seem to have found an interest in hearing how arctic dx is like. So I thought I'd keep you lads busy a bit more.

This file is from Feb 26 at 0600. Conditions towards North America were rather undefined with signals stretching from Ontario/Ohio to the west coast. A few Mexicans too. Again, most Europeans are Russian stations. Note 1485 - NRK Svalbard with regional programming originating from Tromsø before national news on the hour. 1485 is my indicator station as it is located in the signal path. Again, this file will only be available for a few days or perhaps a week.

The file is zipped from original 686 MB to 488 MB. Enjoy!

Sunday, April 12, 2009

Kongsfjord DX Files

Update 16 April: The file has been removed. It is still available on this blog.
I have uploaded a 2-minute 1600 kHz Perseus file to  this location. It is 907 MB, so be sure you have a reasonably quick internet connection before you try to download. It will only be available for a limited time due to storage restraints.

The recording was made on November 1, 2008 at 1300 UTC. Most stations from the Americas are western US and Canada, from Montana/Idaho/Utah to the Pacific coast, Alaska and at least one Hawaiian. The European stations found are mostly Russian.

I was queried about the background noise. The general noise level is low, but I also have a "ticking" noise which is my local powerhouse, the Loran C. It is 250 kW, 14 km away as the crow flies, and in the same direction as North America. The frequency is 100 kHz. This is an extremely challenging adversary, if you excuse the expression. In order to avoid overload to broadband receivers like the Perseus (and many others), a 100 kHz notch filter is crucially important. Stefan Wikander made one for me many years ago, and I've copied that design (and a
modified design by Dallas Lankford) for all my antenna feedlines. Search elsewhere in this blog for details.

To avoid excessive Loran C noise bleed, maintaining the rest of the equipment at a 100%
quality level is equally important and takes a lot of time. For me, one poor connection is detrimental.

Setup: The beverage was fed with RG-316 coax to a self-made antenna connector made up of a cannibalised SE-6 switch box (an accessory to the Sherwood SE-3 sync detector). From the antenna selector to a Wellbrook 10 dB preamp w/ bypass, then to a 1:8 Wellbrook splitter/13 dB preamp w/ bypass. Bypass is important. During nights, often no preamps are engaged. During the lightest part of the day, often both preamps are engaged. I don't remember the preamp settings at the time of the recording, but at least one preamp was on to compensate for the loss
in the 1:8 splitter. Probably both.

Some of the Russian stations are quite strong, such as 657, 1134, 1449 and 1521. These are "local" stations, located on the Kola peninsula. Other Russian stations of potential interest are the VOA station on 810 (Kurkino) and one on 846 ID'ing as Radio Moscow Oblast. Location Electrostal?