"I have a 10 megohm resistor connected across the antenna terminals of the transceiver, so there is never any static charge buildup, although there is no connection to earth ground, either. When a storm approaches, I merely
disconnect my antenna from the transceiver and plug it into the vertical 4-place strip which is mounted to the desk. There, both terminals are shorted together and also connected to the red wire which is clamped to the top copper
"Immediately outside the house that top copper pipe is connected to a ground rod, the telephone company radial ground wire, and the copper water pipe system that eventually connects to the electrical panel ground on the other side of the house. Although cheap and not constructed to the National Electric Code, all I can say is that when combined with prayer and good luck, this simple approach has worked well so far..."
While Walter protects a single dipole and transceiver, Ken protects a 10 meter vertical, an inverted V, and a 6/15/40 meter dipole, plus radio equipment in two rooms which he calls Studio A and Studio B.
Ken says of his grounding system described below: "It's worked well for me since 1995, which was the last time that I ever disconnected ANYTHING! I simply ground all of my antennas and turn off the power strip which controls my radios whenever I'm not actually on the air!"
In Ken's description, after numbering the photos he decided some were duplicates or nearly so and decided to omit those photos.
Here begins Ken's description of his Mailbox Antenna Grounding System: "I have two different radio rooms ("studios" as I call them), "Studio A," which is located at the south end of our house, and "Studio B," which is located at the north end of our house. The white mailbox is depicted during the construction details and shown after completion mounted at the base of my 25' X 4" diameter PVC mast/support pole which supports the 40/15/6 meter shortened dipole. One of the internal Diamond antenna switches (the one at the bottom of the mailbox) is also used to switch my 40/15/6 meter shortened dipole to either Studio A or Studio B. The actual switch positions on this switch (as you will see from photo 15) from left to right: Ground (green sticker), Studio B (pink sticker), and Studio A (yellow sticker). So that I can either ground this antenna when not in use, OR switch it to either Studio A or to Studio B!
Photos #1, #2, and #3 show the installation of the 2" ground strap to the inside and outside of the aluminum mailbox.
Photo #1. This photo and the remaining grounding photos in the article are by Ken Faria, NT0Y.
Photo #2 (see #1 above).
Photo #3 (see #1 above).
Photo #5 shows the Diamond antenna switches after mounting.
Photos #7 and #8 show the coax seal which seals the polished/cleaned copper strap and brass screw ground connection and the Bear tape (see next photo for more on Bear tape) is used to seal the crack at
the bottom of the mailbox door while still allowing the door to open and close. This seals a large crack, thus preventing "rain splash" and ants/spiders/critters
from making their home in your outdoor mailbox and switchbox.
Photo #8: Bear tape is sold here at local Home Depot hardware stores and is identical to "duct tape" but with a MUCH stronger adhesive.
NASCAR also uses Bear tape (or another brand known as Bear Grip tape) to make
temporary body repairs to their race cars during a race. I found from experience that if the mailbox antenna switches are mounted close to the ground (like most of mine are), hard driven rain often bounces UP after
hitting the ground sand and if that crack at the bottom of the mailbox door isn't blocked with Bear tape, the rain and some sand can actually enter via the crack and get the antenna switches and PL-259s wet from "ground splash,"
especially if the switches are mounted too close to the door. With the switches mounted back about 8 or more inches from the door opening WELL INSIDE the mailbox, and the Bear tape blocking the crack at the bottom of the door, rain
splashing up from the ground cannot enter the mailbox, so the PL-259s and antenna switches stay dry - EVEN DURING A HURRICANE WHEN THE RAIN IS WIND DRIVEN! Another important function of sealing the mailboxes at ALL holes and cracks
is to keep spiders, bees, and other bugs from entering and making your mailbox THEIR HOME which they will then defend against anyone who reaches their hand inside to switch antennas! The idea is to TOTALLY seal the mailbox
from rain and "critters" while still allowing plenty of ventilation to prevent moisture buildup and excessive heat under sunny/ very hot conditions.
Photo #10: more sealing of brass screw to copper strap connections and "bug sealing".
I also have an oven thermometer in the mailbox depicted, to keep an eye on summer
temps during very bright hot sunny conditions. The highest that I have EVER seen it go is 105 degrees when it was about 93 degrees outside temp and under very bright sunshine here at my QTH. Some heat is dissipated
through the copper ground strap and into the ground rod, driven into the cool sand, which acts like a heat sink, and the vent holes (especially the big one at the back) also help cool the inside of the mailbox.
I learned a LOT from my earlier proto-type mailboxes, so the ones I make now keep everything perfectly dry under ALL weather conditions WITHOUT COAX SEAL BEING APPLIED TO THE
SWITCHES AND/OR PL-259s THEMSELVES! That way, you can always unscrew the PL259s from the antenna switches and change coax connections without having to remove any tape or coax seal!
Photo #11: shows the rear vent hole drilled with a hole saw and sealed with coax seal and aluminum screen. This gives the box
plenty of ventilation for cooling during hot summer days while also preventing "bug entry". The plastic microwave dish
and plastic scratch dish washing pads you will see in subsequent photos prevent rain splash and wind driven rain from
entering. Even during hurricane Irma, the inside of my mailboxes remained dry with the help of an added small towel
which I rolled up and placed inside covering the antenna switches just prior to the arrival of Irma.
Photo #12: shows the vent holes which I drilled in the microwave dish used
to cover the big vent hole in the back of the mailbox and then I glued some plastic dish washing scratch
pads to cover the TOP holes to prevent wind driven rain from entering through the rear box vent hole.
Photo #13: shows the outer side of the prepared rear mailbox vent cover.
Photo #14: shows the mounted rear vent hole cover which I later sealed around the edge with coax seal.
Photo #15: shows the mounted mailbox outside after my 40/15 meter dipole is
connected to the single so-239 input at the bottom of the antenna switch located at the bottom of the mailbox
and the 10 meter vertical is connected to the single so-239 input at the bottom of the antenna switch mounted
on the side wall. The 3 outputs of the antenna switch at the bottom of the mailbox go to (from left to right)
GROUND, STUDIO B, and STUDIO A. The A-99 10 meter vertical switch on the side wall goes only to GROUND
or STUDIO A only because I didn't have a SECOND underground coax run going to studio B. The mailbox itself is
supported and mounted to FOUR 1" PVC pipes about 3 feet long driven into the ground near the pre-existing
mailbox corner mounting holes where normaly the mailbox would be mounted to a wooden support. I then
drilled a hole at the top of the PVC pipes and ran plastic tie wraps through the holes in the PVC pipes through
the pre-existing holes at the bottom corners of the mailbox.
Photos #17 and #18: show the various coax entries covered
with A/C insulation for U/V protection. The coaxes enter the mailbox via grommeted/coax sealed side holes. The
copper ground strap is connected to one of my ground rods which is also bonded to the rest of my ground system.
My ground system consists of the electrical service entrance ground rod (length unknown), Studio B's ground
rod which is 20ft copper clad 3/4", a 40ft 3/4 inch copper clad ground rod at the base of my 10 meter A99 tower,
a 20ft 3/4" copper clad ground rod located at the back of this mailbox, and finally a 30ft 3/4 inch copper clad
ground rod at the entrance of studio A and ALL ARE BONDED TOGETHER with a double run of #6 solid copper
wire. In between Studio A's 30ft ground rod and this mailbox's 20ft ground rod is the 16ft Aluma tower ground
and mounting galvanized steele post which is buried 8ft in the ground leaving 8ft protruding where the hinge is
for the crank up/tilting aluminum tower. Not the best ground system but it was the best that I could do at my age
and health situation.
Photo #18 (see #17 above).
Photos #19 and #20: more pictures of the final installation.
Photo #20 (see #19 above).
Photos #21, #22, and #23:
Pictures 21-23 are the antennas I am grounding with these mailbox switches. Pics 21 and 23 are pics of the antenna
you hear me on 40 meters, and the support pole is one of my homebrew schedule 40 PVC poles using 2 sections
of 20ft sticks of schedule 40 PVC and some end caps. By the way, this one just survived Hurricane Irma - its
FIFTH hurricane during its life since 1993! I not only ground these antennas with the mailboxes but I also route
them to either studio A or studio B.
Photo #22 (see #21 above).
Photo #23 (see #21 above).
Photo #24: the Aluma tower's mailbox - note rotor cable is within the aluminum flex tubing which is also grounded to my
ground system in hopes of keeping RF from the beam being induced into the unshielded rotor cable and coming
into my shack. That aluminum flex tubing runs all the way from my rotor to Studio A and is grounded to my
ground system at the tower base and Studio A's ground rod. The coaxes are protected by A/C foam insulation for
U/V and weedwacker protection. The red/pink markers are for protection from my lawn maintenance man.
Photo #25: shows the inside of the Aluma tower's mailbox.
Photo #26: the rotor cable connectors. I SPECIFICALLY chose a (SINGLE) MALE 8 pin Jones plug for the rotor cable coming down from the rotor, and (TWO) FEMALE
8 pin Jones plugs - one for the GROUND connections, and one for the "HOT" rotor cable connections which come from STUDIO A's rotor control box. With this
arrangement, it is IMPOSSIBLE to accidentally/inadvertently connect the "HOT" STUDIO A rotor control box's cable to GROUND, and ALSO prevents any accidental
contact of the HOT rotor cable and the grounded interior of the mailbox (since it is also a FEMALE Jones connector). ALL connection possibilities are then
"idiot proofed" in order to prevent "operator error" damage while still allowing grounding of the rotor's internal wiring and rotor cable coming down
the tower to the mailbox when not in use!
Photo #27: Pic 27 shows rotor cable from rotor connected to grounded female which has ALL 8 PINS connected to
mailbox ground strap for rotor grounding when not in use.
Photo #28. shows rotor cable from rotor connected to studio A's rotor control box for normal operation.
Photo #29: shows the internal mailbox ground terminal with coax switches grounded on
output 1 of side wall mounted coax switch, and output 3 of bottom mounted coax switch.
Note additional green/yellow wire which also joins the wire from the 8 pin Jones "GND" female plug
and also connects to a SECOND ground terminal at rear of mailbox.
Photo #30: shows our hi tech "PROFESSIONAL MODEL MARK 5/MOD 3 BROOM", which I found EXTREMELY useful for sweeping up dirt from various rooms in our abode! If you don't
already have one, I highly recommend picking one up! This picture also shows the entry point of my coax
into the underground PVC pipe system to provide some tree root protection to my coaxes and also makes
adding new coax or replacing coax much easier since you only need to dig up the entry points with a spoon
(so to not nick the coax as you might do if you used a shovel), and feed the coax through the PVC (saves a lot
of trench digging).
Photo #31: shows the PVC run from the mailbox to the corner of the house and making a
left turn toward studio A.
Photo #32: shows the rotor cable in one PVC pipe and the coax (kinda dark and hard
to see) in the other PVC making the left turn toward studio A. The conduit you see at the base of the house
in pics 31 and 32 shields my 240VAC coming from the breaker panel located on the opposite side of the house
and this conduit is also grounded in several places to my ground system in hopes of keeping RF from
superimposing onto the 240VAC wires.
This is a recent photo of (L-R) Ken's YL Mercedes, Ken, and oldest daughter Denise.
This is a recent photo of Walter celebrating the first birthday of his grandson, Lenny.
Thanks to Ken and Walter for their very interesting contributions to the December, 2017, Sparks!