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Author Topic: Homebrew Buddipole Help  (Read 1212 times)
N0YE
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Posts: 20




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« on: March 01, 2003, 07:28:59 AM »

I was wondering if anyone has built W3FF's homebrew version of his Buddipole? I just put one together, followed the directions verbatum. I used the exact parts and wire he called for.

I test the antenna last night, and  could not even get it close to resonant on any of the bands for which it was designed. I did not use ferrite beads, but did use a 4" diameter coil of coax wraped 6 times.

Anyone have some suggestions where I might have gone wrong, or ideas that I could use to bring down the swr?

73's
James
petepope@yahoo.com
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AA7EE
Member

Posts: 3




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« Reply #1 on: March 01, 2003, 01:15:11 PM »

Hello James - I strongly recommend that you join the Yahoo Buddipole Users Group (they call it the BUG for short). There are a lot of helpful people on there, including Budd W3FF himself. Read through the posts first, as many people have asked questions about the homebrew Buddipole in the past.

Here's the url for the the group  

http://groups.yahoo.com/group/Buddipole/

If you post a question about the homebrew Buddipole, you will almost certainly receive an answer from Budd himself, amongst others. If you do, please say hello to him from me, as I have been inactive on the group and on the air for a while now.
Best of luck - you will love the BUG!
Dave.
AA7EE, Hollywood, California.
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W6LAX
Member

Posts: 1




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« Reply #2 on: March 01, 2003, 01:28:52 PM »

I recently built a Buddipole using a thick-walled CPVC that has a 7/8" outer diameter (versus the 5/8 he suggests)- thus requiring reduction in the number of coil turns that are suggested in the instructions.  

This is what I did to get an antenna that tunes 1.1:1 across 50 kc of 20 meters and has gotten good reports from Los Angeles all over the US and Canada with 4 watts from my K-1.  I've only had a couple of weeks experience with it, and I am not saying this is the best way to build this or making any claims - but it works surprisingly well.  I intend to experiment with other coils. I am only using it on 20 meters.

First, understand that Buddipoles are not center fed:  they all have one arm that is shorter than the other.  The instructions don't make this real clear, although Bud explains elsewhere that this is part of the design.  You can read others' experiences and many of Bud's comments on the Buddipole reflector that is on Yahoo.  

I started with 41 turns on each coil (per the instructions for 5/8 coils).  It tuned on 20-meters with the arm on braided side of the coax shortened about 6" and the other 44" shorter. Via e-mail, Bud agreed that this was pretty extreme and suggested I experiment reducing the coil size on one side. I worked toward the goal of maximizing the length of both arms and minimizing the number of turns in the coils.

I ultimately ended up with 37 turns on the braided side and 17 turns on the other side, the latter arm about 3 inches shorter than the other.  This was a much bigger difference than I expected. It will tune with other ratios of coil sizes, but not with as low a SWR, so for now that is what I'm running.

I used the beads he suggested and a couple of wraps of the coax in an approx 6" diameter for good luck.

I put mine on a 12' painter's pole, running it about 10' up.

By the way I found the crimp connectors to not work well and replaced them with some audio plugs.

I will be interested in what you find.

Roger
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N0YE
Member

Posts: 20




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« Reply #3 on: March 02, 2003, 07:28:25 PM »

Dave and Roger,

First, a big THANKS to both of you for quick responses to my inquiry for assistance. Glad to be in the ranks with amateurs like yourselves. I wonder why only two hams took the time to try to help someone ? I know there has to be a ton more out there with more knowledge to pass on.

I wanted both of you to know that I took both of your suggestions to heart and had the Buddipole working in no time flat. Works great from 10 down to 20 meters. I still don't have Bud's information for the 40 meter coils, but I am looking forward to working on them.

The idea of using stero plugs really struck home as I have already tired of unplugging the suggested connectors. I will have the new plugs installed this week.

Thanks again to both of you gentleman, your advice really helped me out.

73's
James - N0YE
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KD0AFK
Member

Posts: 245




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« Reply #4 on: April 12, 2008, 05:11:57 PM »

I was going to build this once but had trouble finding the telescoping whips at Radio Shack they don't sell them anymore. Seems that Radio Shack still hasn't changed their name to the more appropriate "Cell Phone Shack". I think we need to find a way to communicate our homebrew project needs in some way that the executives who run Radio Shack can't find out. I appears that when someone comes up with a homebrew project, the people at Radio Shack delete those items from their inventory.
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