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?

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