W6SDO.COM                                                    SAN DIEGO, CALIFORNIA USA
An additional Alpha-Delta 2KW transient
suppressor is screwed onto each of the four
antenna connectors on the back of the

The 160 meter inverted L antenna is cabled
directly from the antenna to the shack since
it has a transient suppressor built in at the
base of the antenna.

Each of the output terminals on the
transceivers is further protected by an
Alpha-Delta transient suppressor that has a
breakdown voltage of 350 volts and a power
rating of 200 watts.

Equipment chassis grounding is provided
by a one inch wide heavy duty copper braid
that runs from a separate ten foot long
ground rod (to help eliminate ground loops),
up the side of the house, through the wall
and then to the ground posts on the back of
the transceivers and amplifier. Although a
better ground strap can be fabricated using
a wide sheet of copper, no RF has been
observed on the equipment knobs or
microphone when operating at full power
using any of the antennas on any frequency
or band. I plan to make lots of measurements
using the MFJ-854 RF Current Meter that I
just acquired, to detect and measure the
level of unbalanced cable braid current.

The belt and suspenders approach
described is intended to protect the RF
equipment from everything except a direct
lightning strike. The ultimate direct strike
lightning protection would require a massive
and very expensive ground system capable
of sinking or diverting both the current and
energy of a full lightning discharge.

For a little more insurance, I may add a
couple of additional ground stakes at the
base of the fiberglass hex-beam mast and
earth the cable braid at this point as well.

Finally, when serious lightning activity is in
the forecast or if I am away from the shack
for a prolonged period, I plan to disconnect
the antennas from the station at the ground
rod junction box.

For additional equipment protection, a heavy
duty Tripp IB8RM 8-outlet 120 VAC transient
absorbing power strip rated at 3840 joules
supplies all of the 120 VAC electronic
equipment in the shack. Transient protection
for the 240 VAC that feeds the linear
amplifier is provided by a Leviton 51120-1
four mode panel protector system.

Snap-on ferrite beads have been applied to
most of the ac and dc control cables in the
shack. MFJ-700A-D snap-on cores are
used due to their convenience in installation.
A few turns around a low cost toroid of the
proper formulation would work just as well.

For personal protection, any antenna ends
that are near ground level are either
terminated at least ten feet above the
ground, are located in areas which are
sheltered from foot traffic or are enclosed
within a suitable length PVC insulating
tubing. PVC sleeves have been applied
over the semi-exposed end of the 75 meter
NVIS dipole and over the lower end of the
vertical dipole.  

The grounding, lightening protection and
general safety approach for the shack will
continue to be improved as deficiencies are
discovered or better technologies become
Every ham station should have a well
thought out and fully implemented plan for
electrical safety and transient surge
protection. This is best done while a new
ham shack is still in the planning stage. It is
much easier and more cost effective, to get
this job done right the first time rather than
having to make numerous, and sometimes
costly, changes, upgrades and
improvements after the shack is completed.
A number of additional measures have
been added to this ham shack grounding
plan since the shack is located on the
second floor.

I have estimated that the cost for this
grounding and lightening surge protection
system will add between 5 and 8 percent
to the total cost of the shack.

In order to help prepare a well thought out
and effective grounding and lightening
protection plan, I first consulted various
ARRL handbooks. In addition there are
numerous very good web sites where
hams described their ground systems,
show their results and list their
recommendations. Based on this review,
I determined that the grounding and
lightening protection plan for my shack
should include at least the following

1. Protect the operator, family, friends,
passers by and pets from shock and RF
burn hazards.

2. Protect the house, property and ham
radio equipment from typical indirect strike
lightening caused damage.

3. Provide for safe and adequate
equipment (dead front) grounding.

To achieve this level of protection, it is
important to effectively suppress the high
energy transient surges that can be
generated by the following:

1. Static voltage discharges (due to low
humidity and high winds),

2. Transient voltages (due to nearby
lightning strike induced voltages),

3. Transient voltages that might be
sympathetically induced onto coaxial
cables due to miscellaneous causes such
as breakdown of the transient suppressor
devices, etc, and

4.  Transient surges on the ac power lines.

This plan is accomplished by using the
several different techniques that are
described here.

The coaxial cable feed line from each of
the antennas is routed to a ground level
location consisting of an array of ground
rods. These rods are located just outside
and just below my second story shack. At
this location, there are three ten foot long
copper plated rods that have been driven
into the ground. They are separated by
about three feet and are bussed together
using a heavy copper buss bar. Each of t
he coaxial cables from the antennas is
terminated with an Alpha-Delta Trasi-Trap
device with a voltage breakdown of 1000
volts and a power rating of two kilowatts.
The response time of the gas tubes in
these protective devices is rated at around
80 nanoseconds so that the damage
causing by energy arriving at the equipment
should be minimal. Each of the suppressors
is connected to the ground stake
buss-work. The surge suppressors are
protected from the elements by enclosing
them in a weatherproof box.
This page was last revised January 16, 2016