Monday, March 18, 2013

Building my Eggbeater II Omni LEO Antennas

Building my Eggbeater II Omni low Earth orbit satellite Antennas for 70cm. 

Eggbeater II
I only had vertical 5/8 ground plane antenna fro 70cm and 2m band and wanted to get better reception on the new cube satellites frequency.
This assembly is based on the Jerry, K5OE Eggbeater II design.
More details at  http://wb5rmg.somenet.net/k5oe/Eggbeater_2.html

70cm Eggbeater II
First get the following items:
1) 2.5 mm SQ (Minimum) Flex cable used in normal 15A plug cable with solid copper core. (about 2m)
2) 50mm PVC Plumbing pipe.(3m lent)
3) 50mm PVC end caps (qty 1)
4) RG65 Coax Cable for matching unit (18.5 cm93 Ohm
5) 3mm x 15mm screw with nuts (qty 4)
6) Spade terminals (qty 8)
7) RG58 or recommended RG213 coaxial cable feed line 50 Ohm.




Tools:
1) Side cutter.
2) Drill and 3mm metal drill bit.
3) Measuring type.
4) SWR meter or VNA analyzer if you have one.
5) Long nose players or crimping tool.
6) Insulation tape.

Youtube video of Egg beater assebly http://www.youtube.com/watch?v=Ai2KiaTMveE





 The 70 cm loops are (17 cm) wide by (21 cm) high and the reflectors is (33.5 cm) long and  (33 cm) below the driven elements

Step by step instructions to assemble 70cm Antenna.
1) Strip the cable from the plastic flex cable.


2) Drill the 50mm PVC end caps with 3mm drill diagonal from each other and mount the wire crimp lugs with the screws and nut.
Crimp lugs
50mm PVC end cap assembled.































2) Bend the wire 21 x 17cm
21cm high
17cm wide
3) Cut the wire end to still give you 17cm with when inserted on external crimp lugs and crimp the lugs with long nose players or crimping tool. (use insulation to hold top section together.)
Assembled active loops
4) Cut two lengths of  cable of 33.7 cm and straiten.

5) Cut about 5mm wide and 1cm deep square cuts out of 50mm PVC end as on picture below.

Cut out squares from pipe end.

6) Then mount the assembled end cap with active elements on to PVC pipe where you have cut out the squares.

Assembled end cap on PVC pipe



5)Then drill 4 holes 33cm below the driving elements diagonal in pipe 
I have drilled 4 hole above and 4 holes below the 33cm distance so I can fine tune the SWR 

Drilled 12 holes 33cm below driver elements

6) Assemble the previously cut 33.7cm wires in the center drilled holes as in picture below.


7) Assembly of feed line next weakened.
Cut the RG-62 about (5 cm) longer than these measurements and leave (2.5 cm) at each end to strip the insulation.
 The 70 cm phasing line is (13.5 cm) long.(add 5 cm to strip 2.5cm on ether side)


Here is my pictures for the assembly of  feed line

13.5cm RG65

RG62 13.5 cm + Rg58 from 70cm Transceiver



















Complete Antenna




Ref: more details at  http://wb5rmg.somenet.net/k5oe/Eggbeater_2.html

70cm Eggbeater Jan 2014
Here is some more pictures from hams who have build the Eggbeater.
70cm Eggbeater Jan 2014





2m Eggbeater Jan 2014
2m Eggbeater Jan 2014

2m Eggbeater and 30m dipole