DX Engineering DXE-UWA-END-KIT How Strong Are These Insulators?

How Strong are the

DX Engineering End Insulators?

Over 6 years ago, DX Engineering introduced the
patented (US Patent No. D534,905) serpentine
style end insulators (DXE-UWA-END-KIT)
which are custom molded from high impact
fiberglass impregnated nylon for tremendous
breaking strength and UV protection. Since then, thousands of the DX Engineering End Insulators have
been installed around the world.

The End Insulators were specifically designed to provide a strong wire gripping method by routing DXE
Engineering Antenna Wire (DXE-ANTW series) through a series of slots in a serpentine manner. This
allows easy, one-step length adjustment for tuning a dipole without having to terminate the wires.

DX Engineering Antenna Wire is a 14 gauge, 19 strand copper wire with a black ‘relaxed’ PVC
insulation. This means the wire remains flexible, lays out flat and won’t coil up when tension is removed.
This wire has been proven to be superior for dipole antennas and has consistently provided years of
service without any problems.

Even when used in conjunction with heavier Baluns and long runs of antenna wire, the End Insulators
continue to provide excellent holding capacity without wire slippage or creeping. DX Engineering uses
the End Insulators in many of our products and assemblies, and sells them separately for your own
projects.

Over the years, Amateur Radio Operators have used many different wire types to construct antennas. This
prompted our Engineering Department to evaluate the DX Engineering End Insulators with several other
types of commonly used wire.

We took samples of four types of wire and the DX Engineering End Insulators to an independent test
laboratory and commissioned a series of pull tests. Tests using the four wire types showed varied results.

The four types of wire tested were:

 DX Engineering Antenna Wire
 Typical ‘Big-Box’ store 14 gauge Insulated Wire
 Bare 14 gauge Copper-Clad Steel Wire
 7-Strand Copper-Clad Steel Bare Wire
 Tinned Copper Flexible Weave Wire with no insulation

When the tests were completed, the results for the DX Engineering Antenna Wire proved that it was still
the overall product of choice for use with the End Insulators.

When using the ‘Big-Box’ insulated wire, it was noted that the wire had a very thin clear plastic-like
substance over the insulation and this would shed much like a snake skin, contributing to creep and
slippage.

The single strand bare copper-clad steel wire was not easy to bend through the End Insulators and showed
a tendency to coil up when relaxed (as expected). But once routed through the serpentine slots it did show
very good resistance to slippage.

The 7-strand bare copper wire showed a tendency to coil up easily when not pulled taut (it had a “helical
memory”) and it would creep and slip faster than compared to the previously tested types.

The flexible weave tinned copper wire was the last one tested. As expected, this type of wire was found to
creep and slip through the serpentine slots most easily.

Following the test laboratory tests, DX Engineering personnel decided to investigate various ways to
enhance the pull strength of the End Insulators. After making a few tests they came upon a very simple,
solderless solution that dramatically increases the termination strength to the point of breaking the wire
before it could creep or pull out.

The ultimate test of the insulator/wire junction does not require a strain gauge to measure. If the wire
itself fails, the results cannot be more conclusive that the installation is the strongest possible.

They used the worst case type of wire - the Flexible Weave tinned copper wire (with no insulation).
They routed the wire through the serpentine slots with an added loop back and through as shown in the
picture below.

Using two trucks as anchors, they tied the ends securely to the rear of each while one slowly drove
forward. The wire did not slip or creep. In fact it seemed to grip even tighter. The wire did stretch slightly
and then broke. It broke in the area between the two trucks, not at the End Insulator. They repeated the test
and the results were the same. The DX Engineering End Insulators held up 100% without failure.

Based on the tests, DX Engineering now suggests routing the wire through the End Insulators as shown. It
will provide extra strength and prevent any creep or slippage of various types of antenna wire.

©DX Engineering 2013

P.O. Box 1491 - Akron, OH 44309-1491 USA

DXE End Insulators - Rev 0

Phone: [phone] - Tech Support and International: 330-562-3200 - Fax: [phone]

E-mail: [e-mail]