Thanks everyone for your feedback to my posting.

I have now been given a lot of information but am starting to go around
in circles.
It seems many people are used to operating at lower frequencies with
huge lengths of wire and hundred of watts of power.

In my application, I am looking for an omni-directional antenna with
reasonable "gain" and fairly low radiation angle. The application
operates with Data at 920 MHz where power levels are below 1 watt. The
antenna must either fix directly to the enclosure (which can be plastic
or metal and is usually only around 100mm x 60mm x 40mm) or within 2-3m
of the enclosure. Therefore, a unit that does not require ground plane
style antenna would be good.
The end-fed antenna style is good because I can build it into the end of
a SMA connector and use 1/4" nylon tubing as the Radome.

Now I just need what goes in the Radome to complete the unit. It is
difficult to install Tee BNC connectors and mid tap points on coils or
transmission lines etc. Stripping coax cable and coiling the coax on the
outside of the Radome is fine as I can cover the unit later with heatshrink.

In my search it seemed the J-pole was a good contender due to its
performance and low radiation angle and ground independence. The shorted
stub version was troublesome but the open stub looked promising.

It appeared as though I could simply use coaxial cable to create the
antenna and fold back part of the coax over 1/4 wave section.

Some have suggested coiling cable to act as a choke at the feed point
and others have mentioned not to do this.

Would anyone by chance have details of a whip antenna that is proven to
work and is similar to what I am trying to construct that I could use as
a starting point ?

Thanks in advance.

Roy Lewallen wrote:
Fred W4JLE wrote:

Suggest you do a google search for baluns coupled with each of the
following
Maxwell, Cebik, and Lewellen.

. . .

Searching for Lewallen will probably be more fruitful than Lewellen.

Roy Lewallen, W7EL