Tag Archives: Homebrew Buddipole

Epic Fail! – Homebrew Buddipole on Military Mast

I took out the military poles and tripod today for the first time with the intent of getting the homebrew Buddipole up around 30 ft. The mast itself works pretty well with the tripod hub. I mounted the Buddipole on top as I have before with the painters pole except this time I replaced the thread adapter with a 3/4″ PVC pipe adapter and used a length of pipe to fit inside the mast section. I guyed it near the top. I sent it up and it promptly got swung around in the wind and tangled in a tree. After twisting and turning awhile I got it clear and up to 28 ft then tied off the guys. I left the last section off as I did not have enough coax to get it in the shack.

Started operating on SSB and made a strong 59 contact into Arizona then noticed that my SWR was swinging around. Looked outside and saw that one half of the dipole was swinging into more of a v-beam. Moments later it fell off completely. Doh!

Photo Jun 17, 1 25 23 PM

The section landed cleanly and did no damage but I had to take the whole thing down. Guy lines get tangled, the aluminum mast sections are burning hot to the touch and my temper starts flaring. Did I mention it’s 97 degrees outside with 51% humidity?

So I carefully sort out the guy lines, move the tripod a few feet away from the tree and place a wedge in to keep it from swinging as much. Sent it up again and adjusted the guy lines. Went back inside the shack and hooked up the SWR meter. It started a sweep and was looking good when I heard a SNAP and the meter SWR reading went full scale. I looked out the window and sure enough the half of the dipole fell again. On inspection I was not so lucky as I broke the whip off at the base. Doh!

So thus ends my Field Day Preps today.I am goign to use something much simpler next week. Either the Homebrew Buddistick which I have used before, an end fed vertical up about 30 feet or a 1/4 wave vertical for 20m with four ground radials. The Buddipole is going to be limited to lower heights using the painters pole. If I had more time I’d try an inverted V for 20m using the Spiderbeam mast.

 

Buddipole 1:1 Current Balun

Here is the 1:1 Current Balun for the Homebrew Buddipole antenna. I sourced the parts kit from Ebay and just had to assemble it as before. This is ready to test as soon as tomorrow. I am planning to setup the 30 ft military pole with the Buddipole for the first time tomorrow if the wind cooperates. This should work very well at 30 ft!

Photo Jun 13, 2 49 18 PM

Photo Jun 14, 5 25 02 PM

Buddipole Tweaks

I was going to try and adjust the loading coils on the homebrew Buddipole but after reviewing the SWR plots in more detail I have decided against this. The resonance point is on the high end of the band but I’ll be operating mainly voice. The SWR is below 1.6 across the band and the reactance is within ±3 Ohms of the resonance point. Better to leave it alone at this point.

I did add a couple of cable ties to the arm to allow me to better control the antenna swinging in the wind. I am working to build another 1:1 current balun which I will replace the BNC to binding post adapter I am runing now. It will be interesting to see if adding this balun will change the SWR curve. Here are the current curves:

BUDDIPOLE CustomBUDDIPOLE CustomA

Hopefully I can retest the deployment of this antenna this weekend perhaps at 20 ft and with luck maybe at 30 feet on the military mast.

Field Day Antenna Selection

Working on Field Day antenna selection this week. I am down to using the Homebrew Buddipole, Buddistick or end fed vertical antenna this year. I plan to operate as 1B battery operation so I am limited to 5W on SSB. This will be my main challenge  this year given the worsening band conditions as the solar cycle continues the drop.

A previous post showed some data on the homebrew Buddipole mounted at 16 ft with a painters pole. I am working on a few tweaks now that will bring resonance into the band and simplify the azimuth adjustments.

The Homebrew Buddistick served me well in 2015 but band conditions are shifting. Here is some modeling data comparing the Buddipole at various heights vs the Buddistick on 20m:

2017-06-12_10-39-07

The Buddipole at 16ft and 20 ft outperforms the Buddistick down to about 25 to 20 degrees. The Buddistick has more gain below these take off angles. At 30 ft the Buddipole is better or equal to the Buddistick from 60 degrees all the way way down to zero.

One thing I could do is use both antennas and switch back and forth as needed. This would not be overly complex to do. My challenge is getting the Buddipole up above 16 ft. If I can get setup using the military poles I can get the Buddipole up to 30 ft and only use the one antenna.

 

 

Field Day Preps Continue

I have two more weekends to prep for 2017 ARRL Field Day. Next weekend I plan to test the Homebrew buddistick on 20m WSPR and compare to the 20m Buddipole I tested last week. I need to complete a 1:1 current balun for both of these antennas. I am also reconfiguring my go-kits. I have a case for solar power generation, another to carry gear for digital ops, and yet another for the FT-817ND and other equipment. I have also sourced a “tarp tent” which I hope to test next weekend as well. Just missing a field portable chair and table at this point. Need the shade and will need plenty of water as well.

My plan now is to run solar powered battery operation from start of the event on Saturday, run 20m & 15m through the day then switch to 40m once the sunsets and operate till the late evening. I will not likely operate on Sunday at all. I plan to start with SSB and switch to digital PSK31 if band conditions limit QRP SSB operation.

Vertical Weathers a Thunderstorm

We had some much needed rain at the QTH last night. I had taken down to work on the Homebrew Buddipole early last evening but left the 40m vertical in place. The storm blew through at about 4am and dropped over an inch and a half of rain with gusty winds up to 25 Mph. My wife went outside early this morning and came in to tell me we had debris in the back yard and oh by the way your antenna is bent. Doh!

Went outside expecting the worst. I have heard stories of fiberglass tubes breaking off in high winds. I was relieved to find that the antenna was indeed bent near the top, but only because the vertical wire had blow into and tangled into a tree branch holding it over. I shook it loose and it popped back vertical instantly. Three sections had telescoped back in near the base so after pulling them back out I am back in business. This SOTABeams travel mast has taken some real abuse!

Homebrew Buddipole Shakedown Testing

Sometime ago I built a homebrew version of a Buddipole horizontal dipole antenna. I only deployed it once to test and have not really used it much since. I am considering using this antenna for Field Day this year on the 20m band and wanted to test it out. Happy I did for several reasons. Here is the antenna deployed at 16ft with a painters pole:

Photo May 27, 1 47 33 PM

The antenna is guyed at two levels. The painters pole is inserted into a speaker stand tripod. Here is the SWR plot:

BUDDIPOLE Custom

Most of SWR is below 2 however the resonance point is outside the band on the high side.  So I have to lengthen the antenna slightly. The whips are already at their max so I will have to adjust the loading coils. One more turn on each should give me room to adjust with the whip lengths if necessary.

Something else that needs to be addressed is that the antenna swings around in the wind. I need to add an attachment point for a separate line to secure it from swinging. The old “Armstrong” method of swinging the antenna around. Finally, I need to put a true 1:1 current balun at the feed-point. I have the kit to build one and will do so this week.

The antenna has performed well. I called CQ this afternoon and made 5 contacts from South Dakota to Florida and North Carolina. Band Conditions have been fairly bad with considerable QSB. Europe will open up in a couple of hours and will try it again then.

 

 

Getting ARES Ready…Hurricane Season Approaches

Hurricane season officially begins on June 1st. Our local club is gearing up some activities to support ARES operations in the event of a storm. We will be setting up a 2m digital simplex net on Thursdays at 7pm local time on 146.580 simplex using MT63 2000. Net control will be Cliff, N5CEY.

I will be net control for an HF voice and HF digital net on Saturday afternoons. Times and digital modes are yet to be determined. NVIS operations on HF will be desirable for these nets. I suspect that my current antenna (the DXtreme 53′ end fed) works fairly well as NVIS as it is up horizontal no more than 20 feet up. This net will give me a chance to test the 40m magnetic loop as NVIS. I am also thinking of modifying the homebrew buddipole to work NVIS as well. There is a PDF file that shows a simple way to modify a Buddipole to work NVIS portable. Yet another option is to build an easily deployable NVIS antenna for 40m and 80m per these instructions (thanks DX Engineering).

I am looking into a few choices for HF digital modes. MT63 1000, PSK31, Olivia and NBEMS. I am thinking of eventually asking net participants to limit power to 20W max to simulate off grid operations.

Last but not least, getting more local hams to test their HF rigs on Winlink using WINMOR. I cranked up the IC-7100 this afternoon and easily sent some emails on 40m to a node in Houston on 20W. Here is a good tutorial on setting this up.

First test of my Homemade Buddipole

Finished and tested my homemade Buddipole this past weekend. I set it up for 20m operation which is full length whips (9.3 feet) and a 2.1uH coil and a two foot extension arm. The whole thing was mounted on an 8 foot painters pole that was extended to 16 feet for operation. When setup at 16 feet the antenna measured to be resonant at 14.32 MHz with an 1Mhz bandwidth of SWR less than 2.

Photo Jun 06, 12 06 59 PM (1)

Overall, I am pretty happy with the way it worked, I do have to work on setting the painters pole up better. I tried 23 feet full extension but it started to bend badly. Will have to work on best methods of setting the mast up as well as adjust the guy wire lengths.