| Author |
Message |
    
Hyperno_1979
Intermediate Member
Username: Hyperno_1979
Post Number: 161
Registered: 12-2005
| | Posted on Monday, September 25, 2006 - 12:41 am: | 
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Tech 833, Paul,
I am going to bite the bullet here and attempt to build myself a 3 element flat top for 11m. Would you have the plans and "destructions" for an absolute beginner to attempt this project so i don't make too much of a mess. 808 recommended you and i know he wouldn't lead me astray....lol. Any help greatly appreciated.
CEFFFCEF
Bob CEF703. |
Tech237
Moderator
Username: Tech237
Post Number: 540
Registered: 4-2004
| | Posted on Monday, September 25, 2006 - 8:57 am: |
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Bob,
If Paul doesnt let me know as I think I do - just packed for moving and it would take me a week or two to locate the box after I mnove this weekend. |
Hyperno_1979
Intermediate Member
Username: Hyperno_1979
Post Number: 165
Registered: 12-2005
| | Posted on Monday, September 25, 2006 - 4:04 pm: |
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Thanx Simon,
I know you are in the middle of a move so in the interest of civility i wouldn't dare ask you to dig anything out just for me. I know what it's like to shift house, i remember the last time Deb and i shifted we had more stand up arguements in one weekend than in the entire 19 years we have been together.....lol now....wasn't funny at the time. I have had a google around but that magic number keeps popping up. $19.95....amazing what people will try to flog off for that. Buy this book...buy that book.....b/s. Convert this from here to here......more b/s. I know i am going to bugger it up so i don't want to spend any more money for the priviledge. Anyway best of luck with the move Simon and i'll catch up when your settled in.
CEFFFCEF
Bob CEF 703 |
Znut
Advanced Member
Username: Znut
Post Number: 724
Registered: 1-2002
| | Posted on Monday, September 25, 2006 - 8:17 pm: |
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Me too Bob. I have most of my plans and materials together. Mine is probably going to be 2 elements. Though I think the boom can be made long enough for 3 I am leaning toward a more compact system as my tower will have a 3 element yagi on 6 meters and an 8 ft stick for 2.
I have a couple big questions about the gamma match. What are the dimensions for one on a 2 and a 3 element? Also, would they be the same if I use 1/2" CATV hardline?
Thanks,
Randy cef 129 |
Tech833
Moderator
Username: Tech833
Post Number: 1451
Registered: 8-2002
| | Posted on Tuesday, September 26, 2006 - 12:39 am: |
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Building a 3 element beam will be a fun project.
You want the director to be about 16 feet long, the driven element to be about 17.5 feet long, and the reflector to be about 19 feet long. The boom should be around 12 feet long and element spacing should be about 6 feet between each.
The gamma needs to be about 20 inches long with some capacitance in series. You will need to do a lot of experimenting with the capacitor value and gamma length. |
Kid_vicious
Senior Member
Username: Kid_vicious
Post Number: 2111
Registered: 9-2004
| | Posted on Wednesday, September 27, 2006 - 9:09 pm: |
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bob, go to http://www.cbcintl.com and check out the "circular polarization" beam antenna plans.
you can just build the horizontal half, or build the whole thing. its a pretty neat concept!
good luck,
matt |
Hyperno_1979
Intermediate Member
Username: Hyperno_1979
Post Number: 170
Registered: 12-2005
| | Posted on Friday, September 29, 2006 - 12:08 am: |
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I think i'm gunna need more than luck Matty....lol. But i'll find one that doesn't bamboozle me with technological mumbo jumbo and see what sort of pretzel i can "destruct". Thanx heaps guys.
CEFFFCEF
Bob CEF 703. |
Znut
Advanced Member
Username: Znut
Post Number: 726
Registered: 1-2002
| | Posted on Sunday, October 01, 2006 - 8:12 pm: |
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Will 75 ohm hardline work for the gamma match? |
Patzerozero
Senior Member
Username: Patzerozero
Post Number: 3240
Registered: 7-2004
| | Posted on Sunday, October 01, 2006 - 10:42 pm: |
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not to take anything away from paul's info, bob, if you wanna cheat, buy the maco gamma matches, & you can get the maco 3 element beam instructions from http://www.majestic-comm.com/assembly/index.htm. you can 'copy' the maco gammas, to a point, by using a piece of solid center 9086/9913-type coax with the braid & covering stripped off, inserted into a piece of aluminum tube. it would function just as the maco gamma. again, lots of experimenting, or an antenna analyzer if one's available, & it would be completely homemade. |
Hyperno_1979
Intermediate Member
Username: Hyperno_1979
Post Number: 186
Registered: 12-2005
| | Posted on Monday, October 02, 2006 - 9:51 pm: |
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Spot on Pat,
After cruising around all the sites that everyone has given me i am leaning to the Maco 103 as it has the most comprehensive plans and then just buy the gamma match to suit. Then watch the fun. I can get the tubing very cheap through work so all i have to add then is the price of the gamma. About the cheapest 3 ele i can buy new here is around $249 so i'm thinking if i take my time and don't make too much of a mess of it i should come out well under that price. Cheers and thanx for all your help guys.
CEFFFCEF
Bob CEF703. |
