Bavarian Contest Club DJ5MW & DRØW

  Contesting from Germany`s most southern corner

Manfred Wolf
DOK: T13
HSC #1579
AGCW #2626
RTC #56

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In 2002 I decided to build a big 10m monobander for CQWWs. As sun spot cycle is declining I wanted the posibility to let the antenna grow to a 15m or 20m Yagi, too.

Moreover material should be easy to get in Germany and the antenna should be a 50 Ohms design with isolated elements.

Stefan/DL1IAO helped me a lot and computer-designed a 7ele and 4ele Yagi for 10m and a 5 ele Yagi for 15m.

For the 4ele I used some parts of a KLM KT34XA, the 7ele was built of new material.

The boom is 12m long and consists of two 6m long tubes 50x3mm connected in the middle by a 1m long 55x2 tube.

The 10m elements are made of: 25x2mm (2m) and 20x2mm (2m)
15m is extended with a 16x2mm (1m) tube, which has to be reduced in diameter on a lathe to fit into the 20x2 tube.

20m elements will finally end into a 12x1 and 10x1 tube.

I used some plastic boards to isolate the elements from the boom.


Here are some details of how I finally built it: 

 

Element center: 25x2 tube secured to the plastic board by 8mm screws (A2)
2 54mm clamps are used for boom connection


detail of driven element.


10m 4ele mainly built from KT34 parts. (Austrian alps in the background)


10m 7ele in the foreground

 

 


 
 


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