Ham Radio

Tuesday, February 17, 2009
Home brew IOIo (MK 6) Step by Step Assembly
Since last summer many off you have contacted me regarding the Satellite antenna designed by EA4CYQ which is known as the IOIo beam. I already have built a total of 5 IOIo antenna's so far, all slightly different made up of anything available at hand. As many of you already know I have been working the ISS and many Satellites from my shack using IOIo beams with good results running QRP.

So with the feedback and fantastic comments I have been receiving I thought I would try a next version using some materials I had knocking around.
 But this time I thought I would share the build and decided to post the step by step instructions here at ham radio operator blogspot and planet ham.The EA4CYQ original design was followed and this is how it goes!

Materials used:

12mm aluminium box section tube. (boom)

3mm plastic sheet. (insulators and clamps)

2.4mm Welding wire. (elements)

Various self tapping screws.

Cable ties.

50 ohm feeder/coaxial cable. (2 lengths for dual bands)

Sponge foam and insulation/sticky tape. (handle)

Step 1) The IOIo paperwork.  I made the elements from 2.4mm diameter T.I.G welding wire which worked out at:
 145 mhz reflecting element( I )= 1004mm.
 145 mhz loop element ( O) total length = 2058mm. 
435 mhz reflecting element ( I )= 337mm. 
435 mhz loop element (0) total length = 642mm.
 The spacing of each element from back to front = 
152mm, - 324mm, - 100mm, -  51mm & - 108mm. 
(visible on the drawing , click to enlarge).
Step 2) I don't like wasting materials so I joined two short scrap pieces of tube together by filing some 12mm round bar into a square interference type fitting.
Once filed up I was able to tap the squared round bar into the ally tube to join the boom. 
Once mated up it gave a total length of 1000mm (1M) 
Step 3) Using some 3mm plastic sheet I drew a desired shape and cut the plastic using a hand shear otherwise known as a bench knife. The sheet at this stage is used to insulate and  mount the elements to the boom. Also mark the element spacings using a marker pen on the boom.
Step 4) drill 6 holes that will allow the cable ties to hold the elements as well as clamp the insulated mounts to the boom. I drilled the centre of the plastic so I could see the previously pen marked position of each mount easily on the ally boom. Just one more to go giving a grand total of 6 plastic insulated mounts.
Step 5) Here you can see the central holes showing the spacing pen marks of the boom. Once lined up, pilot drill the boom and attach the plastic mounts/insulators using self tapping screws.
Step 6) Time to solder the 50 ohms coaxial feeders to both loops, then cable tie (tie rap) the elements to the fitted insulator mounts. 
A close up of the 435mhz Loop and reflecting element cable tied and soldered up.
Repeat the technique for the 145mhz side of the antenna and use a separate 50 ohms feeder. Once this stage is complete the IOIo starts to take shape and just needs the elements fixing firmly. 
Stage 7) I cut a 50mm x 1000mm strip of plastic, aligned the elements and using more self tapping screws I was able to clamp down the elements. This stiffened up the antenna and prevented the elements from moving out of line. The antenna is now ready to solder the plugs on to connect to your desired radio. I used 2 PL259 plugs.

Here is a closer look at the bottom side of the finished mk 6 IOIo antenna.  (the front end 435 mhz )
The full picture showing the bottom  side of the finished antenna.
The view here shows the complete antenna from the top side.Here is a close up of the finished project.
I tried it using my old Yaesu FT-470 and was very pleased when I opened up a repeater 25 miles away +60 db on 145mhz. It worked well also on 433mhz providing me with  instant and easy access into the local 70cms repeater. (not bad to say its resonant on 435mhz and I was inside my qth using less than 5 watts.) I will try it on a satellite over the next few days.

So once again I was pleased with my antenna tinkering and this model was much lighter so I shouldn't get too much arm ache when I am out playing. 
 I hope some more of you have a go at making one. Thanks to all of you again for telling me about your personal experiences in building Satellite antenna's for Amateur Radio. I look forward to hearing more about your projects and I hope to hear you coming through loud and clear via the "birds". Good luck and best 73
posted by Simon Davison @ 6:11 pm  
6 Comments:
  • At 10:04 pm, Blogger Phaze58 said…

    That One looks the business Simon
    Now all you've got to do is get down to a motorbike shop and "Get A Grip" hi hi

     
  • At 11:44 pm, Blogger 2E0HTS Simon said…

    Thanks Phil,

    I am getting a dab hand at making them now h.i.

    Well you know me, 3 bikes, 4 spare kwacker 750 engines, so i am sure there will be a nice rubber grip in the garage somewhere!

    Nice pic of Kevin on your blog h.i see you soon.

    Si

     
  • At 1:18 pm, Blogger Phaze58 said…

    How is the other `project comming on ? I cant wait to see it .

     
  • At 6:03 pm, Blogger paddy said…

    It is a Great Antenna easy to tune. I made a ioio yesterday, copied
    UR5BFX in Ukraine Ternopil appx
    8793 km from qth HYderabad in India. He was 57 through the FM repeater.
    Never knew I cud a long haul on the IOIO

    73,s
    paddy
    vu2pep

     
  • At 6:04 pm, Blogger paddy said…

    It is a Great Antenna easy to tune. I made a ioio yesterday, copied
    UR5BFX in Ukraine Ternopil appx
    8793 km from qth HYderabad in India. He was 57 through the FM repeater.
    Never knew I cud a long haul on the IOIO

    73,s
    paddy
    vu2pep

     
  • At 6:20 pm, Blogger 2E0HTS Simon said…

    Congratulations Paddy on your new home brewed IOIo antenna. I am sure that you will have as much fun as I still am having with mine.

    Happy DXing & Satellite chasing!

    All the best 73

    Simon

     
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