DK7ZB Duoband Yagi 2m/70cm 2+2 Elements

Duoband DK7ZB Yagi 2m/70cm with 2 Elements on 2m and 2 Elements on 70cm and one Feedpoint

• 4,12dBd on 2m
• 5,4dBd on 70cm

Original design: https://www.qsl.net/dk7zb/Duoband/duoband_2-70_2-3.htm

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VNA measurements taken in a home room - so they may differ from how the antenna works on the roof or in the field. It will be possible to make a slight correction by shortening the elements with a file.

Originally made of boom, about 62 cm long - 20 cm from the Reflector 2 m - this allows the rear attachment to the mast or the installation of a bicycle handle and use as a portable antenna.

Attention !!!

Adding plastic plugs to the antenna at the end of the aluminum elements "lengthens these elements", which causes a shift in the operating bandwidth. If you are planning something like this, take it into account.

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Printed parts:

1. box_bottom.stl - 1 pcs
2. box_top.stl - 1 pcs
3. choke.stl - 1 pcs
4. clamp.stl - 3 pcs
5. boom_cap.stl - 2 pcs (optional)

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The length of the antenna elements (all 6mm aluminum tube):

1. Open-Sleeve-Element 70cm - 318mm
2. Radiator 2m / 70cm - 2 x 464mm
3. Reflector 70cm - 322mm
4. Reflector 2m - 1022mm

The spacing of the mounting holes in the boom is shown in the attached photo.
From the left, further elements: Open-Sleeve-Element, Radiator, Reflector 70cm, Reflector 2m

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50 Ohm Choke:

1. 40cm RG-316 (or similar) - See the attached photos

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Additional materials:

1. Boom - Aluminum profile 15mm x 15mm x 1,5mm
2. Antenna Elements - Aluminum tube 6mm diameter
3. M3 x 30mm screws (5 pcs)
4. M3 x 10mm screws (10 pcs)
5. M3 nuts (9 pcs)
6. N connector
7. RG316 cable (43 cm)
8. Aluminum sheet or aluminum angle (N socket ground connection with boom - see pictures)

Aluminum elements, M3 screws, nuts bought in a DIY store (Castorama)

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