Wednesday, June 12, 2013

Home Built Buddistick Antenna

Home Built Buddistick Antenna

W3FF made the original instructions on building a home built Buddistick. He commerically manufactures the Buddipole and Buddistick. This is the Buddistick that I made. It was built similar to the instructions but I changed a few things. I didn't use the speaker wire, I used # 14 enamel wire for the coils and inside the bottom tube. The top piece I made from 1/2" PVC and drove a 3/8" X 24 coupling into the 1/2" PVC (it makes a tight fit). If you use the alternate whips I would do it differently (see below). Down Load the complete instructions below.

I made the bottom pole first. It is made from 3/4" PVC sch. 40, 26" long. I drilled a small hole 1" from the top and bottom (only through one side of the pipe). I then put in a # 14 enamel wire inside the pipe and put the wire out through the holes. The bottom wire only needs to be 1" but the top will need to extend out about 6". On the bottom I drill two holes (at right angles to one another) for 6 / 32 bolts (one of the holes need to be close to the wire). Insert the bolts and nuts. Scrape off the enamel off the bottom wire and secure it to the bolt closest to it (I soldered a lug on mine). Place a second nut to hold the wire onto the bolt and then place the Wing nut on the bolt. On the other bolt place a Wing Nut on the bolt (this will be used for the coax shield and Radial).

Cut the coil forms according to the chart below (use 3/4" PVC). Drill a hole all the way through the PVC (this should be a tight fit for the # 14 enamel wire) 1" from each end, the holes should be oriented the same way. Push one end of the wire all the way through the pipe leaving about 6" exposed. Wind the number of turns indicated in the chart below and then push the end all the way through the pipe to secure the coil.

Whip Mounting Detail 9 1/2' Whip w/3/8 X 24 Thread

Alternate Whip Mounting Detail 72" Whip w/1/4 X 20 Thread

Mounting the antenna, I put a 3/4" plug into a coupling (slip on one end for the plug and threaded on the other end for the antenna) and mounted the assembly on a spring clip. I can then place the spring clip on a table etc. It works good up to ~ 1" table, if thicker it will then lean to one side. I'm working on a different mount.

Attach the Radial and Coax, the Radial is an elevated Radial, it doesn't touch the ground.

Using the above chart as a starting point, hook-up your antenna analyzer and find the lowerest SWR. If the frequency is high then you will need to lenghtened the radial, etc.

If you don't have an antenna analyzer then you will have to use your SWR meter on your radio or tuner. To get the approximate setting for your tuner tune for maximum noise and then check the SWR.

Whip Mouting Detail 3/8" X 24

Buddistick Components Whip - Coils - Bottom Pole - Clamp

Buddistick Antenna Top Section

Buddistick Antenna / Bottom Section 10M, 12M, 15M, 17M Configuration

Buddistick Antenna / 40M Coil / Bottom Section

Operating & Tuning - Home Made Buddistick

I did an analysis of the Buddistick that I made. The radial lengths are different than what was published in the article as I built mine a little different. I corrected the table above. I used EZNEC to model each configuration. Below are the results, showing the SWR curve for each band. It is based it on a height of 4' (off the ground) for the Buddistick and 1' at the end of the radial. The radial has to be above ground. 

10 M SWR Curve 
12 M SWR Curve 

15 M SWR Curve 
17 M SWR Curve 
20 M SWR Curve 
30 M SWR Curve 
40 M SWR Curve 
60 M SWR Curve

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