If it is a true quarter wave, and not one that is shortened by loading 
coils, read on. shortened antennas are more complex, so the formula 
below applies only to a standard quarter wave length antenna. It also 
does not apply to a 5/8 wave antenna, or to a Ringo type antenna. Most 
of the installation notes, however will apply to them.

you can get the length for a quarter wave from the equation 234 
divided by the frequency. Since most of the activity on 10 meter SSB 
is between 28.3 and 28.5, especially during marginal conditions, and 
since a full size quarter wave has a fairly broad band width, I would 
use 28.400 as the center frequency of the antenna. This calculates to 
a length for the vertical radiator of 8.2 feet.

That would be 8 feet, 2.4 inches.

If I were doing the measuring, I would scrap the .4 inches, and just 
set the length at 8 feet, 2 inches.

Set the length of the radials a bit longer. I would probably start 
with something like 8 feet, 6 inches on the radials.

If you have a General or above license, but have absolutely no 
interest in working CW, you can use 28.500, or 28.600 and cover most 
of the phone band.

Now, let's be sure that a few other things are in their correct 
places. There was a time when I didn't know some of this stuff myself. 
So, not knowing how much you know about antennas, and at the risk of 
sounding as though I'm talking down to somebody when that is *not my 
intention, here goes.

First, disconnect the feed line from everything on both ends, and 
check it for shorts. If you don't have an Ohm meter, or a continuity 
checker that you can use to do that, find a local ham who has one, and 
ask for help.

While the feed line is disconnected, also check for a short between 
the vertical element and the radials. *You do not want to find a short 
here. The radials themselves will be shorted together, but they *must 
not be shorted to the vertical radiator. This statement may not be 
true for some 5/8 wave models because of their matching arrangement.

Once you know things are okay in the shorts department, you are ready 
to try again.

Let's look at your installation location options.

For 10 meters, I highly discourage ground mounting. Get the feed point 
of the antenna as high in the air as possible. About 15 to 20 feet or 
higher is ideal, but 5 or 10 feet will beat the heck out of ground 
mounting.

If you are in a second floor apartment or higher, try the balcony 
railing. If that railing is metal, use it as all or part of the radial 
system. If there is a roof above your railing, simply tilt the 
vertical outward enough to clear the overhang. Having operated 10 
meters from just such a location for a number of years during the 
1990s, believe me when I say the antenna will still work very well if 
it is not absolutely vertical.

A ground floor apartment may be a bit more challenging in the "higher 
the better" department, but you do the best you can with your 
circumstances. In this situation, try to mount the antenna on a patio 
fence, yard fence, etc. If you have a metal patio or parking pad 
cover, try to use that cover as the ground plane.

In the absence of such a fence, get hold of the April, 2011 issue of 
QST, and read the article about the Florida ham who used tent stakes 
and a 5 foot mast, plus radials made from speaker cable to get on the 
air with a collection of Ham Stick type moble antennas. In his case, 
the radials also served as support cables for the mast.

Keep working on it, and you will get the antenna going on 10 meters. 
Once you start having fun, all that work will be worth the effort.






Mike Duke, K5XU
American Council of Blind Radio Amateurs