A CHEAP & EASY BASE ANTENNA

[Needle Bender]

Would you like to get on the air with a respectable signal but not spend a lot of money on an antenna at first?

...well, I'll probably get assassinated by someone from Sirio, MACO or Solarcon for letting out this 'secret ' - but, here goes...

OK, Many WWDX readers already know about this simple 1/2 wave antenna, but I imagine we get a number of people who simply read & learn but may never sign up or post...
So,
- if you have any type of 3/8" x 24 thread mobile antenna mount which you can adapt for the top of a mast,
and which has an S0-239 coax connector on it,
simply mount it atop your 3, 4 or 5 section mast with any 102"-103" stainless steel or 96"-102" fiberglass whip.

[ Make certain your 102" whip mount has a good insulator! ]

Then, guy the mast safely at each 10' section with non-metallic guy line, like parachute cord,
EXCEPT for the top set of guy lines...
- start them at the top with (three or four) 108" lengths of METAL guy wire attached at the base (bolts?) of your 102" whip mount ("ground").

Then attach the lower ends of those 108" (1/4 wave) metal guy lines to your top set of parachute cord guy lines and pull them down & out, tightly at some basic diagonal angle so the top set of guy lines are metal on top but parachute cord the rest of the way down, and double as the bottom half of your antenna.

...and you've basically made a Starduster, which is simply a center-fed 1/2 wave (vertical) dipole.

Your SWR should end up somewhere around 1.2:1

Now, if you can get this on top of a 4-5 section mast ON your roof, you'll have a serious performer both locally & for DX!

...and NO MATCHING CIRCUIT to burn up or pack up with dirt or snow.

ALSO:
- If you install this on a strong insulated fiberglass rod, so the bracket touches no mast nor metal except for the 108" metal wires & your coax,
then wrap a 5 & 1/2 turn choke in your coax, around a 4" diameter plastic or PVC former and right below the 102" whip hub coax connector...
- you'll have a smokin' clean pattern and probably wouldn't even bother local computer speakers, since there would be near ZERO (common-mode) RF currents coming back down either the mast or coax.
It might be a good idea when doing this to ground your coax before it comes into the house to help bleed off static to ground. A lot of people simply add a barrel connector there and ground it outside the wall.

Stay safe & have fun!
73

 

[M0GVZ]

Alternatively instead of having a vertical with effectively no gain get a couple of bits of wire and make a dipole, place it horizontally or as an inverted V, stick it up at least 16ft and have more gain than almost all vertical CB antennas have for less money than the homebrew Starduster above.

If you're feeling flush and can afford a few dollars more than the cost of 16ft of wire for some bamboo sticks to use as spreaders then make a Moxon Rectangle and get 5 times the gain of the dipole.

 

[Needle Bender]

Alternatively instead of having a vertical with effectively no gain get a couple of bits of wire and make a dipole, place it horizontally or as an inverted V, stick it up at least 16ft and have more gain than almost all vertical CB antennas have for less money than the homebrew Starduster above.

If you're feeling flush and can afford a few dollars more than the cost of 16ft of wire for some bamboo sticks to use as spreaders then make a Moxon Rectangle and get 5 times the gain of the dipole.

I agree - but for DXing not local work.
Horizontal polarization is much superior to vertical as it includes additional 6+dB of ground gain, but for local chit-chat around town you'd actually see 15-20dB of loss as about 98% of local CB base station operators and 99.9% of mobiles are vertically polarized.
I was hoping to offer an idea to those who would like to try their hand at building a simple local (and DX) vertical antenna without spending $200 or more, just to get them on the air with a respectable local signal.

 

[wavrider]

1/2 " EMT conduit, available at Home depo,t lowes, ace hw, etc for around $2 a 10' stick, great building material for verticals and yagi elements,

1/2 wl vertical dipole, center insulated by some pvc or wooden dowel, old shovel handle etc split coax and connect shield to lower half, center conductor to top half and wrap an rf choke at feed point, works great for a vert.

As for DX, flat top dipole. inverted V, is good, delta loop is awesome, hard to beat an inverted triangle fed at the bottom for horizontal polarization and cheap to build,