Monday, March 18, 2013

Building my Eggbeater II Omni LEO Antennas

Building my Eggbeater II Omni low Earth orbit satellite Antennas for 70cm and 2M. 

70cm Egg Beater

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.
2m Eggbeater II
The 2 meter loops are 51 cm wide by 63 cm tall; 2 meter the reflectors are 100.5 cm long and 101 cm below the driven elements.
137 MHz WX Sat Dimensions
 The loops should be built with # 8 AWG wire and the reflectors should be increased to about 1/4" diameter. The loops will be 54 cm wide by 66.5 cm high. The reflectors will be 107 cm long and 108 cm distance from the feed point. The RG-62 will be 45 cm long (plus 2.5 cm at each end).

Phasing line
The 70 cm phasing line is  (13.5 cm) long and the 2 meter phasing line is (41.5 cm) long. Cut the RG-62 about (5 cm) longer than these measurements and leave (2.5 cm) at each end to strip the insulation, peel back the braid, strip the center conductor, and attached the ring lugs.


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)
Feed Line connection Diagram



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

Here is some pictures of the construction of 2m Eggbeater


2m Feedline
RG65 and RG58 feadline (2m)
2m Top support


Assembly of top section (2M)

2m Feed line connection


Adding phase and feed line (2M)
2m and 70cm Eggbeater Antenna
Add caption


Some more pictures from Hams

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


My new 2m Egg beater

I had some problems with Big OWL bending my 70cm Eggbeater antenna several times where after I decided to redo the 70cm Eggbeater with bigger 5mm Aluminum Rods.

Bend by Large Owl
Owl


Here is a picture of my refurbish 70cm Eggbeater.
I had to bend the Aluminum with a gas torches heating up the corner when bending it as it broke if I tried to bend it if it was room temperature .
5mm Aluminum Rods in place of 2.5mm Coper wire.


Bent with gas torches.

3 comments:

  1. A very good antenna...It hears good horizon to horizon...No loss of signal over head...

    ReplyDelete
  2. How can I use one handy talkie to QSO using one 2m and one 70 cm eggbeater antenna, with separate coax cables?

    ReplyDelete
    Replies
    1. Hi
      You can use a duplexes or diplexer

      Link to diplexer http://www.giga.co.za/ocart/index.php?route=product/product&product_id=257&search=diplexer

      or Duplexer

      http://www.giga.co.za/ocart/index.php?route=product/product&product_id=383&search=duplexer

      Delete