Tuesday, January 29, 2013

January 2013 Verifications

CISL Richmond BC 650
KCVR Lodi CA 1570
KBLA Santa Monica CA 1580
KFAN Rochester MN 1270
KSHP North Las Vegas NV 1400
KOLT Scottsbluff NE 1320
KSEL Portales NM 1450
KCBL Fresno CA 1340

Saturday, January 19, 2013

A Software Challenge For The G33DDC

Software bundled with SDRs suffer from the need to satisfy customers with a wide variety of preferences. Special functions or needs are not catered for however, and will usually be subject to third-party developers. DX-ers with special requirements will either have to know how to develop these solutions themselves, or have to rely on developers who understand what they’re after.

The Perseus SDR soon had quite a variety of third-party applications, albeit of varying quality, serving special needs. Some are shareware/freeware, some are restricted («teamware»). There has been very little development going on for the G33DDC.  One reason is probably that (at least in Europe) the Perseus is used by a lot more MW DX-ers, so the focus has been on that radio.

Typical for bundled SDR software is the lack of focus on recording and playback of ddc files. The G33DDC software fares a lot better than Perseus with regards to live and scheduled recording. The playback function however fails to recognize 1) the DX potential of extended recording sessions, and 2) how extremely time consuming playback of many ddc recordings is.

My objective is to find out if it is possible to make a basic ddc playback application where ddc files can be checked at a much higher rate than the G33DDC software allows. This is indeed possible, I am using this approach today. I’d like to know if anyone here share the same objective, and have the necessary programming skills to cooperate with me. I am very much aware of what this application should do.

Contact info: bjarne.mjelde at gmail.com 

Sunday, January 06, 2013

Remote Control - Or Being 170 km Away From The Dial

The KONG antenna farm is located in Kongsfjord, Arctic Norway, at 70.72 degrees north, and 29.35 degrees east. That's just south of Barrow, Alaska and a little east of Istanbul, Turkey. You didn't expect Norway to stretch that far east, did you? Now, the antenna farm isn't very impressive compared to other MW sites in Arctic Europe, but its proximity to the sea shore partly outweigh the disadvantages of short beverage antennas. Another important factor for a good, permanent DX site is good infrastructure, such as stable power, road connection and not least:  Internet connection. All this combined with an extremely low RF noise level makes it a very attractive location. Most readers will know about the KONG DX-pedition every October, but in fact we're there every day now, thanks to a 450 MHz internet link.

OJ Sagdahl and I have set up PCs and SDRs to record automatically. Theoretically, we could let the equipment stand there during the winter, pick up the xxx TB of recorded stuff in spring, and check the recordings during the summer. But we're DX-ers aren't we, so we like to twiddle the "knob" live as well. And we also want to know what was heard last night, not only 8 months ago. So we turned to the possibly best software since Star Trek to beam us up to Kongsfjord: LogMeIn.


LogMeIn comes in two guises: The Free and the Pro version. The Pro version  is the software you need for the "host" PC. This enables audio to be sent over the internet. Without audio, you won't hear much DX. Besides, file transfer is a breeze: Cut/copy and paste from remote to local. LogMeIn runs in a browser, so it is independent of your operating system. Another very useful software from the same company is Ignition, which lets you access the remote site without using a web browser. In fact, Ignition can be installed a USB memory stick, so you can access the remote site from any PC you have access to. Ignition is Windows only, but is also available as an Android app. There is also an iOS app available for iPad/iPhone, which for some reason is not named Ignition but LogMeIn for iOS.
Access to my 3 PCs via Ignition

What remains then is a stable internet connection. In Norway, Sweden, Denmark and Poland the old Nordic mobile phone frequency range at around 450 MHz is used for broadband internet. The speed is not impressive, typically 500 to 1500 kbps down and 200 to 800 kbps up, but in most situations this is totally adequate for LogMeIn.

Remote control with LogMeIn Pro is quite straightforward. Due to the distance (I suppose the internet signal travels not 170 km but 170 times 170 km before reaching its destination), there is a 0.5 - 1 second latency in key presses and mouse clicks. Occasionally more. The latency slows down operation a bit, but one gets used to it.
Win7 PC in Kongsfjord remote controlled from my Win8 PC at home
Video quality is fair, audio quality is in fact very good. There is the occasional audio stutter, but as long as we record ddc files to the host's hard drive we won't miss an ID due to stutter. The stutter seems to increase though if the audio has high peaks, such as during splatter and Loran C noise. In fact, the most infested Loran C frequencies can cause the connection to all but freeze, with keyboard latencies of up to 30 seconds. I suppose this is a bandwidth problem.

Client/server not an option

There are CSOs available for several SDRs, but since we need to control the PC and not only one single SDR, they are not used in Kongsfjord. I have up to four SDRs, all of different brands, running on one PC so controlling the PC itself is the most practical solution.

Alternative software?

There are other programs available for remote control: Teamviewer, Radmin, Anyplace Control, Remote Utilities, Google and many others. We haven't tested any of these, and it's not likely that we will. LogMeIn has been working well for several years now and we see no need to change.

Thursday, January 03, 2013

LKE/LLE 1314 kHz Test Transmissions

The past few weeks, Bergen Kringkaster/LA1ASK together with veteran MW DX-er Svenn Martinsen have challenged European DX-ers with test transmissions from the former NRK Bergen site. LKB, operating on 890 kHz, closed operations in 1978 together with many other low- and medium power NRK transmitters, among them LLE (ex-LLU) 1466 kHz from Odda.

The test transmissons were conducted on the former Kvitsøy frequency 1314 kHz, with powers around 100-200 watts. Since I am 1572 km away from transmitter site I thought this could be a real challenge, and basically it was, but on December 27 at 0730 UTC I was able to pick up morse code IDs at good levels. Spain's Radio Nacional dominated the frequency, but morse code always wins...

At the time of listening, they were running at 120 watts from this WE 451A-1 transmitter.
Photo: Bergenkringkaster.no
The antenna was a modest 15 meters high Comrod/Tjøstheim vertical:
Photo: Bergenkringkaster.no
On the receiving end was an Afedri SDR-net receiver, connected to a 500 meter beverage directed at 50 degrees. Bergen is located at the center of the back lobe of the beverage.

I happened to be the most distant listener (so far), but they appeared to get out well in both Norway, Sweden and Finland.

Thanks to the LA1ASK crew for their time and effort!