Friday, March 2, 2012

Contest station DR1A

The Station

The amateur radio station DF0CG/DR1A was designed specifically for the participation in contests, both for domestic and global competitions. First in line are the contests run by the Deutscher Amateur Radio Club e.V. (DARC): Worked All Europe DX Contest (WAEDC), Worked All Germany Contest (WAG), DARC 10m Contest and the DARC Christmas contest. Participations from DF0CG/DR1A yielded top scores and several new records.

Within the DA0HQ team, DF0CG/DR1A represents the DARC e.V. in the HQ competition of the IARU HF Championship on 20m (SSB) and 15m (CW).

The four biggest team events of the year are the contests of the american CQ magazine: CQ WPX SSB (end of March), CQ WPX CW (end of May), CQ Worldwide DX Contest SSB (end of October) and CQ Worldwide DX Contest CW (end of November). DF0CG/DR1A participates in these contests in the "Multi/Multi" category, meaning that multiple operators (typically around 16 OPs from different countries) operate simultaneously on the six 'classic' amateur radio bands 160m, 80m, 40m, 20m, 15m and 10m.

Beyond being on the air, there is a multitude of other activities at DF0CG/DR1A which in total represent the appeal of our hobby. One the one hand there is hands-on work: Most towers, antennas and cables were acquired as surplus from commercial radio providers at low cost. Often, it was up to us to manage and fund the disassembly and transport of the material. Reconstruction of the systems on the DF0CG/DR1A premises required the active participation of many helpers who already invested thousands of work hours into the common project.

Besides the widely visible towers on the exterior of the station, six radio rooms ('shacks') were created on the inside of the leased building, one room for each of the six radio bands mentioned above. Several kilometers of coaxial cables and control wires connect the shacks with each other and with the antennas. A cafeteria as well as bathroom with shower, four small bedrooms with a current total of 10 beds allow for appropriate accomodation of the participants and for an enjoyable contest experience.

The development over time can be followed by the pictures in the the Gallery on this web site.

Another focal point of our activities is hardware and software development: Units such as our "4-TRX-Manager", "PTT-Collector", "PTT-Analyzer", "Electronic Rotor Control Units" cannot be bought off the shelf but had to be custom developed for our needs and built in small series in-house. This is the playing field of several team members who enjoy soldering iron and software development rather than sitting in front of a microphone or a morse key. Hats off to you guys! Without you we could not be on the leading edge!

Even if units could not be developed by ourselves, such as the recently acquired electronic power meters of U.S. company Wavenrode or the USB CW keyers of MicroHAM, there is always an integration effort which creates regular work for our IT administrators. The PC network at DF0CG/DR1A comprises of 13 PCs and 3 servers. Software updates are regular activites, such as Windows updates, Win-Test updates, updates of the MASTER.DTA and Country Files, etc.
Speaking of Win-Test: We would like to thank the french colleagues of Win-Test for their great response whenever we have suggestions for improvements and bug fixes of their software, where we support with qualified feature descriptions and bug reports! This friendly international cooperation is working well.

Another current project which is designed to support active contesters and DXers worldwide is the operation of our own Skimmer server on our premises. We are running a QuickSilver QS1R SDR receiver (tnx DL2OE) on a high-performance Quad-Core PC (tnx DL6FBL) using the Software "SkimmerServer 1.3" of VE3NEA. This allows monitoring and processing of the lower 192 kHz of up to seven ham radio bands. The software automatically decodes CW transmissions in these band segments and reports the decoded callsigns to the web platform "Reverse Beacon Network" (RBN), which is currently fed by some 50 receivers from all over the globe. Ham Radio operators and scientifically interested persons can obtain valuable real-time information on shortwave propagation and use it for their purposes. This way, DF0CG/DR1A provides some of its antenna receiving performance to the general ham radio public.

Antennas & Towers

Next we like to show you the individual towers and other equipment:

Tower 1
Build: 03.APR.2004 - Beams: 20m-Stack(5/5) - Height: 38m

It's a 24m high wind turbine tower with swing bearing and on top of that a 14m climbable steel mast is mounted resulting in a total height of 38m. With that it's currently the tallest tower.

Since the summer of 2009 the 2nd stack for 20m is mounted here with the 2 times 5 element Cushcraft-beams.

Tower 2
Build: 31.JUL.1999; Beams: 15m-Stack(5/5) - Height: 30m

The tower is a 18m tall construction tower with sides of 1 by 1 meter. The tower is part of a 48 meter tower, that was taken down in 1991.

In the summer of 2009 we put a turning device with a 30m rotating mast to mount the two 5 element Cushcraft beams.

Tower 3
Build: 29.July.2000; Beams: 20m-Stack(5/5) - Height: 32m

The tower is a self supporting tower composed of a 12m RWE Utility tower that we made longer by 6 m. The rotating part is located in the tower base and rotates a 32m long mast that holds the 20m stack. The 20m stack consists of two 5 element Yagi antennas from ON7LR. The first antenna is mounted 19m above ground, the second 31m. The antenna boom is 16m long.

Tower 4
Build: 29.July.2000; Beam: 40m 3-Element-Yagi - Height: 35m

The first 19m of the gyed construction tower (part of a 48m construction tower) was already errected in the year 2000. In the late summer of 2006 the tower was lengthend by 15m to reach its current final height of 35m above ground.

Here at 35m our 3 element 40m Yagi is mounted. The rotating part that sits in the base can bring the antenna in position via a 35m long mast.

Tower 5
Build: 31.July.1999; Beam: 15m-Stack(5/5) - Height: 37m

Until now there we had 30m of construction tower from the west tower that we build up in 1997 at another place.
In the summer of 2009 we finaly rebuild the tower. The top of the tower was taken off and cut at 25m in order to put a 37m tall rotating mast inside for the 15m stack. THe mast supports the two 5 element Yagi's from ON7LR, one at 26m and another at 36m height above ground.

Tower 6
Build: 03.April.2004; Beam: variable - Height: 29m

We took down the tower in February 2004 at a formal armed forces location.
The tower is cone shaped from 3m*3m at the base up to 1.3m*1.3m at the top. On top of that there is a 4m*4m large working platform at 29m above ground.

This tower will be rebuild in the future.

Tower 7
Build: in the future, no date has been set yet.

This tower was taken down at the same location as tower 6.

It has 3 parts of 6m each and will be lengthend to 25-30m.

Until then the tower will most likely spend its days laying on the antenna lawn.

Tower 8
Build: 03.April.2004; Beams: 2 * 10m-Stack(5/5/5/5) - Height: 38m

This tower used to be a tower for mobile communication and was taken down by us in October 2003. It was build up during the 3-tower activity.
It has a height of 30m and at about 16m we installed a flood light so we don't need to walk in the dark accross the antenna lawn

Tower 9
Build: 20.September.2009; 80m Vertical-radiator - Height: 21m

This is our newest tower. A 21m high vertical radiator for the 80m band that if necessary can be made longer for the 160m band.

Furthermore we have layed out a 3.6km radial net around the radiator.

All towers have their own switching cabinet the base, the so called tower-connection-cabinet.
The tubes with coax, supply and control cables fthat come from the tower-connection-room in the basement end here. At the same time all cables that come from the tower end here and can be routed to the specific cable towards the basement.

Hier muss noch ein aktuelles Bild hin von einem Mastanschlusskasten
Every tower-connection-cabinet is equiped as follows:

2-3 coax cable 7/8" Hardline-coax
1 control cable 16 * 2 * 0,8mm²
1 control cable 12 * 2 * 1,2mm² (every pair individualy shielded)
1 supply cable NYY 5 * 2,5mm² for lighting purposes)
1 supply cable NYY 5 * 6mm² (supply cable for distribution box)
distribution box with 1 * 32A CEE, 1 * 16A CEE , 3 * Schuko
Motor control / Rotor control
24V permanent voltage, 2 circuits fused seperately
1 light with 60W-bulb (so that you are not in the dark)

For the future we plan to put up tower number 7, as well as to put up second stacked systems for the 10m-20m bands. Now that we have a full size 40m beam we still need a yagi for the 80m band.
For the far future four square antennas for the 80m and 160m bands are planned for which we need the proper space.

In this way we still have years of work ahead of us before we are finally ready.

Apart from these big Antenna monsters that can be seen from far, we also have conventional "wire antennas", that should not be disregarded.

At this moment we only use dipoles for the 80m and 160m band, which we hung up horozontally between the the tops of a few towers.

The possibility is also there to put up horizontal deltaloops for 40m and 80m that are then located also on the antenna lawn between the towers.

Also we have some beverage antennnas for the low bands (40m, 80m and 160m) around the yard available:
two Phased Beverages to 280 degrees (abt. 280m long)
two Phased Beverages to 300 degrees (abt. 140m long)
one Beverage to 100 degrees (abt. 280m long)
one Beverage to 45 degrees (abt. 180m long)
one Beverage to 225 degrees (abz. 180m long)

Some more interesting stuff:
Until now we dug out about 200 cubic meters of dirt which was filled with the same amount of conrete for the tower bases.
Also we dug out 150 cubic meters of dirt to place the tubes for the antenna, control and supply cables.
Up to now we placed at least 2300m of tubing between the tower-connection-room and the 10 tower-connection-cabinets
We have placed 1470m of DN60-tubes for the hardline coax cable and 720m DN100 tubes for the rest of the cables.
In October of 2005 Markus pulled all of the 7/8" hardline coax cables with a total length of 1738m through the tubes. Apart from that 870m of control and 870m of supply cable were pulled and layed down between the tower-connection-cabinets and the tower-connection-room

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