Home of Dustin Cox, N0DRC - Dustin's Projects

Home

Dustin's Projects

Welcome to my projects page! Below are some of the projects I am currently working on for the best hobby in the world! Please feel free to use any of the information below. I have also included links to documents that give the information about how to build some of the projects and informational sheets for setting up some ham radio programs. (ie. EchoLink, ect.) All project information is free to be used and copied. If you do place a link to a document that you have downloaded from my site onto your site please be sure to give me credit for my work. Thanks!

Current Project:

Building a Simple 1/4 Wavelength Ground Plain Antenna (DRC-1 Antenna)

Below is the materials list that you will need to build this simple antenna. This antenna also has a modification that can be done to make it a base antenna. (See below for the modification.)

Materials List (Without Mod):

~1 Copper wire 19 5/16�

~4 Copper wires 20 3/16� each

~1 5.5 FL. Oz Tube of Kwik Seal (Any type of sealant will work)

~1 SO 239 Connector (You can find this a Radio Shack)

~Any length of coax.

~4 bolt for bolting on the radials (or can be soldered)

~4 nuts for the bolts (if you don�t solder)

~8 flat washers (if you use bolting to attach the radials)

Added materials for modification:

~ 1 8ft stick of Schedule 40 PCV 1�

~ 1 1� PVC Cap

~ 2 1� pipe mounting brackets.

Build it! (See drawing below)

The vertical element and radials can be made of #12 copper wire or welding rods, coat hanger, etc. The vertical radiator (A) should be soldered to the center connector of the SO239.

The four base radials (B & C) and (D & E) can be soldered or bolted to the SO239 mounting holes using 4-40 hardware. The four base radials then should be bent downward to a 45 degree angle.

The antenna can be mounted by clamping the PL259 to a mast or even passing the coax through a 3/4 ID PVC pipe and compression clamping the PL259. Either way let your creativity work for you. If you plan on mounting it outside, apply RTV or sealant around the center pin and PL259, and TAPE WELL, to keep water out of the coax.

Make each radial a 1/4 wave of your desired xmit frequency. Sometimes it helps to add a little extra length to the radials and radiator. This will give you some adjusting room when you adjust the SWR.
(If adjustment is needed, clip all radials equally about 1/8 inch at a time while checking SWR, USING LOW POWER). Center the lowest swr on your transmit operating frequency.

Example Calculation:

Freq (mhz)       146
A (inches)         19 5/16 (Note "A" length is to the SO-239 insulator but not critical)

B THRU E (INCHES)   20 3/16

LENGTHS FROM FORMULA (234/FREQ MHZ X 12 for length in total inches) + 5 % LONGER FOR RADIALS

TRY ONE ON 440 or other bands USING SAME FORMULA AND CONSTRUCTION TECHNIQUES!
ENJOY AND EXPERIMENT!

This is a omni-directional vertical antenna.

To view diagram in a larger form click on it.