Thursday, June 23, 2011

Contest station DF0CG

The station DF0CG

Antennas & towers

The antenna meadow of DF0CG

Mentioned already before we began only 1999 with the structure of the station.

Before this of course there was a mast in the inner court directly beside Peter´s terrace, with 4 times 11 element yagis for 144MHz and sometimes a FB 33 or FB 53 was installed for short wave contests.This mast was dismantled however in 2003, since all masts had to be placed on the antenna meadow. On the foundation of this old mast meanwhile one of the sturdiest child wood huts of the world is developed for Peter's son Tizian.

Now back to the antenna meadow, the actual battleground.
During the years starting from 1999 we developed towers and antennas here, dug and provided pipe trenches with empty pipes, set up mast connection boxes, placed wires and some kilometers of cables.
Despite all that we reached not the end and we still have a few years for the last masts and antennas.


Starting in the year 1999 with the planned participation in the WAEDx contests we made the concrete in the summer and poured two foundations. Later we set up the first masts at DF0CG, the Tower No. 2 & 5.

In the following year we repeated the same and developed thus the tower No. 3 & 4.

In 2001 we dug again the antenna meadow to place another hundred meters of empty pipes to the new and further planned masts and/or the mast connection boxes which we to have set up there.

In 2002 we developed the first antenna stack for 20m on the tower No. 3 and erected the 10m stack provisionally at tower 5.
We used 2003 for the preparation of a further larger action. For this however 2 towers had to be diminished at their original location and transported to DF0CG.The first mast is a former portable radio mast with 30m height which we diminished in October 2003. The second tower is a former German Federal Armed Forces latticed mast with a large platform in 30m height which we diminished in February 2004.
In a large weekend happening in April 2004 we placed the three new towers 1, 6 & 8 to use in the following CQ WPX contest in CW with antennas.

We want to explain the individual masts and the further equipment:

Tower 1:
Build-up: 03.04.2004 - Beams: 15m-Stack 5 over 5 Element Yagi since 24.04.2004

It is a 24m high wind wheel mast with ball race and where upon a 14m mountable steal tube tower is placed, from which an overall height of 38m results.
It is thereby our presently largest mast.

Since the structure we developed the 15m stack with the two 5-element-Yagis of ON7LR but in the future we will install the 15m-stack at tower 5 in the same height, in order to be able to install here a 20m-Stack.


Tower 2:
Build-up: 31.07.1999; Beam: Hiygain 155 since 31.07.1999

The tower is a 18m high grid tower with 1m*1m set length.
This mast is a section of a 48m tower, which had been already diminished 1991.

Since 1999 we installed there a 5 element yagi for 15m at a Ham IV rotor.
Soon we will develop a 10m stack here.
The turning unit will be on the ground and an approx. 30m long revolving tube will turn the two 10m beams.

Tower 3:
Build-up: 29.07.2000; Beams: 20m-Stack 5 over 5 Element Yagi since 07.09.2002

The tower consists out of a conical 18m grid tower (a 12m RWE electric power mast), which we extended by 6m.

The turning unit is on the ground and turns a 32m long revolving tube with the 20m stack over 500 degrees.

The 20m stack consists of two 5 element yagi antennas of ON7LR.The first antenna is 19m above ground, the second one 31m above ground.
The antenna boom has a length of 16m.

Tower 4:
Build-up: 29.07.2000; Beam: 40m 3-Element-Beam since 09.09.2006

The first part of this tower was build up in july 2000 and 19m high. The tower has a side length of 2m*2m on the ground. On the first 12m the mast approaches conical up to a side length of 1m*1m.

First we installed the 5 element yagi from Hygain for 10m here at a HAM IV rotator.
For CQWW SSB in 2004 we developed a 5 element yagi for the 20m band here.

In september 2006 we installed another 15m long section on the top of the tower to it´s finally height of 34m over ground.
The 3-Element-fullsize-Beam for 40m is installed at the top of a 35m long revolving tube, turned by the turning unit on the ground.

Tower 5:
Build-up: 31.07.1999; Beam: Shorty-Fourty since 20.10.2004

Up to now we had a 30m grid mast from Westerntower there.
So far we had used this mast for 40m, 20m and 2 * 10m yagis.

With the mast action 2004 we had to prepare the upper section of the mast with all antennas for its future task.
At present it measures a height of aprox. 26m, however in the future it will increase up to 37m.
Here a revolving tube is to be built as with the tower no.3, in order to construct here a 15m stack in the future.

Since the CQWW SSB 2004 we developed a second antenna for the 40m band here.

Tower 6:
Build-up: 03.04.2004; Beam: 20m 5-Element-Cushcraft since 30.04.2006

We diminished the tower in February 2004 at a former German Federal Armed Forces location.
The mast approaches from 3m*3m over a length of 30m conical to 1,3m*1,3m side length.
At a hight of 29m above ground is a 4m*4m large platform.

Since the CQ WPX CW 2004 we have the 3 element yagi for 40m installed there, but that the antenna crashed in a snowstorm in CQWW-CW 2005. After that we installed a 5-Element-Yagi in April 2006.

In the future we will extend this mast with further 12m to mount a 3 element yagi for the 80m band.

Tower 7
Build-up: in future, but still not planned

This tower was diminished at the same location as tower 6.

It consists of 3 elements, each 6m long and it will be extended up to 25-30m.

Until this happens the mast will probably still spend some time lying in peace on the antenna meadow.

Tower 8:
Build-up: 03.04.2004; Beam: 2* 10m 5-El.-Yagi ON7LR & 1* 105 Hygain since 20.10.2004

In former times this tower was a portable radio mast and was diminished from us in October 2003.
It has a total height of 30m and on approx. 16m height we have a 2kW power light, so that we do not have to grope on the antenna meadow any longer in the dark.

In the future the second 10m stack will be installed here: one fixed USA 5 element yagi for the 10m band and an upper antenna of the same type rotatable.

Since the CQWW SSB 2004 we installed here also the old 5 element yagi from Hygain towards the south.

Each tower has its own switchgear cabinet, the so-called mast connection box.
All the empty pipes coming from the mast connection area in the cellar end here to bring up energy and control cables and the coax lines.
At the same time all cables, which come from the mast, end here and are jumpered together. Each switchgear cabinet is equipped as follows:

  • 2-3 coax 7/8" hardline
  • 1 control cable 16 * 2 * 0,8mm²
  • 1 control cable 12 * 2 * 1,2mm² (each pair individually protected)
  • 1 power cable NYY 5 * 2,5mm² secured for lighting purposes
  • 1 power cable NYY 5 * 6mm² (feeding cable small distribution)
  • small distribution with 1 * 32A CEE, 1 * 16A CEE, 3 * Schuko
  • motor control/rotor control
  • 24V continuous tension, ever 2 electric circuits separately secured
  • 1 lighting with 60W lamp (to get sole light in the dark)

For the future we plan the structure of towers No. 7, as well as the structure of second stacks for10m-20m band. After we built up our new 40m-fullsize-Yagi, we still need a kingsize-yagi for 80m. For the far future also foursquare antennas for 80m and 160m are planned.

Thus we have still a few years to work untilwe are finally finished.

Beside these large, far visible antenna things we have also still conventional "wire antennas", which are not to be neglected.
At present we only use dipoles for the 80m and 160m band, which we fixed on the top of some towers crosswise horizontal over the antenna meadow.
At the same time we have the possibility to develop lying delta loops for 40m and 80m, which are likewise placed on the antenna meadow between the masts.
Beside the antenna meadow on a small green tire there is still sufficient place for a K9AY-Loop.
In addition we can set up some beverage antennas around the yard as receiving antennas on the l low bands (40m, 80m & 160m).

In the past years we did extensive earthwork on the antenna meadow to get this infrastructur.
So far we dug 200m³ soil, in order to fill in the same quantity of concrete for the mast foundations there.
We dug 150m³ soil, in order to place the empty pipes for the antennas, control and power cables.

We shifted aprox. 2300m at empty pipes from the mast connection area in the cellar to the 10 mast connection boxes.
We put aprox. 1470m DIN60 tubes for the hard line coax and 720m DIN100 tubes for the remaining cables into the ground.

In October 2005 Markus pulled all 7/8" hard line coaxes with an overall length of 1738m into the empty pipes.
Also 870m control cables and 870m power cable between the mast connection boxes and the mast connection area were pulled so far. However still some hundred meters will have to be pulled until all mast connection boxes are completely wired.

In the upcoming years still some working sessions on the antenna meadow are planned, because there is still some hidden potential of the station.

There is still much to do thus...

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