Manufacturer changed URL for that Technical Note again:
TN CR 002 The Need for Coordinated Protection

http://www.erico.com/public/library/...es/tncr002.pdf
This figure demonstrates how a radio can be protected even
from lightning strikes.

Static is irrelevant to radios because, as was posted
Every electronics manufacturer ... takes great lengths to
control static.
If static on an antenna was destructive to a radio, then every
time a human static discharges to that radio (many times
higher voltage), then the radio is damaged. But human static
discharge does not damage those JFETs. Internal protection
easily installed because static has such low current AND short
duration. Radio design assumes an antenna has been properly
earthed as even required by the NEC which therefore makes
internal protection effective.

Cell phone towers, 911 dispatcher radios, telephone
switching computers connected to overhead wires everywhere in
town. All must suffer direct strikes and not be damaged - as
was standard even before WWII. Why? Earthing, as described
in the below text, and demonstrated in that manufacturer's
figure makes protection even inside the radio effective.

If such earthing was not effective, then 911 emergency
dispatch and telephone operators would have to remove headsets
(stopped working) during every thunderstorm. They don't stop
working, do they. Protection so routine that it even makes
static electric discharge problems irrelevant and trivial by
comparison.

OPs antenna and antenna lead must connect as demonstrated by
that industry professional's technical note. For that matter,
visit this and many other 'real world' manufacturers whose
products are also effective because they discuss the most
critical component - earthing.


Lancer wrote:
On Fri, 13 Feb 2004 14:41:50 -0500, w_tom wrote:
The antenna requires an earth ground, first, as required by
National Electrical Code. That mounting rod should be
connected to an eight+ foot earth ground rod (available even
in Home Depot and Lowes). This required by NEC for human
safety, but also to protect transistors.

Incoming wire should enter building at the service entrance
so that a ground block (maybe $1 at Radio Shack or Home Depot)
connects 'less than 10 feet' to the building's single point
earth ground. Same earthing ground that also connects to AC
electric, telephone, and cable TV wire. Do not even think an
AC receptacle or water faucet will provide that necessary
earthing.

NEC requirements have changed since 1990 to require a
service entrance ground rod. You may need to install this
earth ground rod at the service entrance. Many homes don't
even have that much which is another reason why some homes
suffer household electronics damage.

Principles are demonstrated in this figure. Note an antenna
tower and building each have their own earth ground. Each is
earthed as if it were a separate structure. Every incoming
wire makes a connection to that earth ground. To make the
'system' work better, a ground wire interconnects the antenna
and building earth grounds:

Static is irrelevant. A few hundred volts of static will
not damage any properly built radio. You could even static
shock your car radio antenna or a portable radio antenna
without damage. That would be as much as 18,000 volts - and
still no damage.

The earthing is required by NEC for human safety AND also
provides transistor safety. If lightning is provided a path
to earth ground via that exterior rod, then it too will not
seek earth ground, destructively, via your radio. Direct
strike lightning damage is that easily avoided.
Unfortunately, too many don't have necessary earthing, suffer
damage, and then declare nothing could have helped.
Generations of technical history say otherwise. Its all about
earthing - as even required by code.