Homebrew Buddipole

Looking for a portable and versatile antenna, I settled on building a homebrew Buddipole. It is based on the design by Budd Drummond W3FF. The document containing his design can be found here. When I first constructed my homebrew Buddipole, I followed Budd's design to the letter. Here is a photo of the components all laid out for inspection.

The balun form is an NDS 4 in. PVC DWV Drain Cap ($1.94 at the Home Depot). Fifty feet of coax, with a BNC connector on the end, were used to form the coax balun and feedline. Seven turns of coax are held on the balun form using tie wraps. A hole was drilled in the center of the drain cap for a center tee adapter to slide through.

On the center left of the photo is my adapter between the Buddipole's center tee and a wooden painter pole coupler with an Acme thread. A Mueller Streamline 3/4 in. x 1/2 in. PVC Schedule 40 Slip x MIPT Reducing Male Adapter ($0.87 at the Home Depot). The orange coupler is press fit into the 3/4" slip opening. A small ring of corrugated cardboard fitted over the 1/2" thread acts as a shim when the adapter is inserted through the hole in the center of the balun and screwed into the tee. The photo below shows how the adapter connects to the center tee. The matching of the orange color of the painter pole threaded plastic to the orange tape is a happy coincidence.

I very quickly discovered that the slip fit couplers presented a design "flaw" that required immediate attention to find a solution. Below is my post to the Buddipole User's Group (BUG) found on Yahoo Groups:

• • • mac4pcs 10 Jul, 2013

    • Being one to tinker, it was only a matter of time before making changes to my homebrew Buddipole. One of the aspects of the original homebrew design that I didn't like was that all of the sections were held together with 1/2" slip fit couplers. When used in plumbing, they are glued together. With the homebrew Buddipole, all that holds things together is friction. I've already had my Buddipole fall apart several times during testing. I certainly didn't want that to happen during transmit, as that would be a disaster. I decided to spend about $15 dollars and purchased CPVC CTS male and female adapters and some CPVC cement. All of the components of my homebrew Buddipole now screw together. I no longer have concerns that the antenna will come apart unexpectedly.

    • w3ff 11 Jul, 2013

    • Good job, Mac. I love to see variations of this take-apart design. Will check to see if these parts are readily available all over the States. I love the color scheme too. Budd

    • mac4pcs 11 Jul, 2013

    • Budd, thanks for your kind comments! Both Home Depot (where I purchased mine) and Lowes sell the CPVC fittings and the adhesive in the Dallas, TX area for about the same price. I can't speak for the rest of the country, though.

Here is a photo of my updated homebrew Buddipole. Note that the addition of the threaded fittings adds to the length and weight of all of the components. I consider the additional weight a minor sacrifice for the peace of mind in knowing that the antenna won't "spontaneously disassemble".

The coils, pole adapter, and tee fit nicely into a re-purposed contact lens travel case. The whip sections, arms, balun, and feed line fit snugly in a Sunpack tripod case. The external strap on the tripod case provides a convenient means to secure the travel case.

Prior to using my Buddipole, I needed to tune it. Initially, this was a bit problematic, as I did not have an antenna analyzer. I worked addressing that problem by designing and constructing my homebrew 'Tenna Dipper. Tuning appeared to be promising, but I decided that I needed a "real" antenna analyzer to do a proper job of it. Fortunately, I was able to borrow an MFJ-269 HF/VHF/UHF SWR Analyzer from a fellow ham (Thank, Jeff, N5RPL!). I have been able to obtain good tuning on the 20, 17, 15, 12, 10, and 6 meter bands. My testing results using the MFJ-269 are presented in the PDF listed below.

As part of the Richardson Wireless Klub's "Show and Tell Night" in October 2013, I prepared a presentation on my Buddipole. There wasn't time for me to actually use the presentation, but it helped me to prepare to give an "ad hoc" presentation. Note that the testing shown in the presentation was perfromed using my 'Tenna Dipper.