Spider
Antenna
Project Using
Ham
Sticks
Eugene
Bradeen, KX1C
This project came about after seeing an advertisement for a multi-band antenna made from ham sticks. There are several on the market, from MFJ and Chameleon, among others. The antenna looks like a spider when all four bands are installed. Presently, I have only three bands installed, 6M, 10M, and 20M. On the Chameleon website they had a decent picture of the internal construction, along with the name of the company making the octagon box. I ordered a box from Newark. The ham stick mounts, 3/8-24 thread, were ordered from Quicksilver Radio. A chassis mount SO-239 connector is also needed. A parts list with sources is shown below.
The box that I purchased is 5 inches across by 1 ½ inches deep. I drilled holes that were centered in height and symmetrically located round the perimeter. Four of the mounts are wired together and go to the center pin of the SO-239. The other four are wired together and connected to the chassis. I flattened the ends of the ring adapters that came with the mounts to make a wider spot to solder the #12 wire.
I offset the chassis mount SO-239, so that there was room for the mast mount and for tightening the PL-259. Also, a small hole was added to let moisture out, since the box is not waterproof.
The mast mount was made from a piece of bent scrap stainless steel, 3” X 8 ½”. Holes were drilled to attach the mount on the box, allowing clearance for the SO-239 connector and centering the mast on the box to balance the antenna. I drilled two sets of holes in the mount for use with two different sizes of masts. Stepped drill bits worked great. Drilling the holes left a little rough edge. Just a touch more with the bit cleaned up the edges with a slight chamfer!
Two ham sticks are required for each band you want to use. They are mounted in a dipole configuration directly opposite from each other. I put the 10M sticks perpendicular to the 20M ones and the 6M set in between. The antenna balances quite well in this configuration.
Tuning the ham sticks takes a little patience. I started with 20M and adjusted to less than 2:1 SWR. I found the 10M and 6M ones interacted a little. More patience. Tuning back and forth between them got the SWR to around 1.7:1. The auto tuner will take care of the rest.
Using my KX3/KPA100 running at 70 watts on 20M, I made a contact in Maryland. He gave me a 5/4 signal report. Not bad for having the antenna on a 12 foot mast mounted on the back deck!
Watch where you put the antenna. The close proximity to my Davis anemometer caused RFI to give me a high wind speed of 92MPH! Oops…
I think the antenna went together fairly easily. It will be good for portable use, camping, SOTA, or just about anywhere you go.
Parts List:
3/8-24 Antenna mount w/ring lugs Qty. 8, Purchased from www.qsradio.com
Newark P/N 61T5010, Octagon Die cast box, Mfg. Hammond, P/N 1590STPC Purchased from www.newark.com. Waterproof version P/N 1590WSTPC
SO-239 Chassis mount w/hardware
#12 wire – 12”-14”
Ham Sticks 2 for each band. Purchased from www.qsradio.com
Hardware for mounting to mast, L-bracket with U-bolts or pipe flange.
