Years ago ( when I was a young SWL )
my radio antenna was protected with a "lightning arrester".

As I remember it, it was a glass "brick" with three terminals;
ANT; GND; and RCVR
It was filled with neon, so it'd glow with electrical discharge.

I'd like to add lightning protection to my new antenna,
but I'm having a heckova time finding "lightning arresters".

At best, I see listings for "surge protectors".......
and, as I understand it, these are a one-time protection,
which counts on burning out a "mov-diode" for the first strike.
( as for subsequent strikes ???? )

Any sources ?
rj

If you even feel there may be lightning unplug your antenna from your radio.
It is the only sure way to protect your radio.

Greg
"RJ" wrote in message
...

Years ago ( when I was a young SWL )
my radio antenna was protected with a "lightning arrester".

As I remember it, it was a glass "brick" with three terminals;
ANT; GND; and RCVR
It was filled with neon, so it'd glow with electrical discharge.

I'd like to add lightning protection to my new antenna,
but I'm having a heckova time finding "lightning arresters".

At best, I see listings for "surge protectors".......
and, as I understand it, these are a one-time protection,
which counts on burning out a "mov-diode" for the first strike.
( as for subsequent strikes ???? )

Any sources ?
rj

"RJ" wrote:


Years ago ( when I was a young SWL )
my radio antenna was protected with a "lightning arrester".

As I remember it, it was a glass "brick" with three terminals;
ANT; GND; and RCVR
It was filled with neon, so it'd glow with electrical discharge.

I'd like to add lightning protection to my new antenna,
but I'm having a heckova time finding "lightning arresters".

At best, I see listings for "surge protectors".......
and, as I understand it, these are a one-time protection,
which counts on burning out a "mov-diode" for the first strike.
( as for subsequent strikes ???? )

Any sources ?
rj

Yikes! An on-topic post! What to do, what to do... :-)

While power line spike supressors do use MOVs, I don't think
you'll find them used in RF applications. They aren't one-shot
(unless you take a direct strike), but they do degrade over time
from each strike, eventually shorting out.

As for the term "lightning arrestor," it was just a case of a more
appropriate name being taken. Most surge protectors/spike supressors
cannot handle a direct strike. HOWEVER, THERE ARE EXCEPTIONS!

The best known and most commonly available of these are from
PolyPhaser corporation. The next most available to the SWL are from
I.C.E. (Industrial Communications Engineering).

The Polyphaser model I'd recommend for SWLing or low power
transmitting is IS-B50LU-C0 or IS-50LU-C0. (The "B" version is a
thru-hole bulkhead mount; the other is a flange mount.)

This next sentence is very important, so read it until you can see it
on your eyelids at night: A SUPRESSOR WILL DO NOTHING IF IT IS
INSTALLED IMPROPERLY!

What does that mean? Well, the best way to deal with lightning
strikes is to create what is called a "ground window" -- basically a
sheet of copper or other conductive metal -- to which all lines to
your "protected" gear must pass through supressors on that sheet. Use
120 VAC to power your radio? There must be a good supressor on that
ground window for it. Use a computer? Either protect it or run the
data line from the radio through a supressor. Protecting the computer
but connecting by cable/phone-line/etc. to the internet? Put a
supressor on that line.

Again, an important sentence: Even one wire -- an extension line, a
phone line, whatever -- bypassing that ground window renders it
useless.

Now, not to be too obvious, but the ground window needs to be
grounded! I'm not talking about an 18AWG wire to a 3 foot RS
ground rod, I'm talking multiple ground rods spaced twice their
length apart, connected with copper *strap*.

Now, "doing it right" can be expensive, but it's cheaper than the
damage to your radio. You can also do it a step at a time. For
example, you may want to put together a suppressor and a ground
window and a single ground rod. That will protect you from a lot
of near misses but not a direct strike. Get more ground rods in --
3 or so, bond them all to a single point, bond the house ground to
that (it's the law!) and shoot for a good powerline supressor or
alternate means of powering your radios, like gel-cells.

You can get the supressors direct from Polyphaser, I think, or from
Hutton Electronics, Electro-Comm, Cable-X-Perts, or Ham Radio Outlet.
You can get a catalog from Polyphaser and get an idea on what they
provide.

There is a myth about lightning that nothing can save your gear from a
direct strike. That is blatantly untrue: Cell towers and radio/TV
towers get hit all the time, and if they are properly installed, they
stay up through a strike. But the attention to detail required is
substantial. As an example, running a coax down a tower then at the
8 foot level running it into a building is a disaster waiting to
happen; running the coax down to the base of the tower, bonding the
shielding to the tower leg at the base, then back up the wall of the
building to run in is safe.

hope some of this rambling helps...

Eric

--
Eric F. Richards,
"Nature abhors a vacuum tube." -- J. R. Pierce, Bell Labs, c. 1940

Always disconnect your antenna when not in use.

Bill, N5NOB

(WShoots1) wrote:

Note that with solid state receivers, any neon bulb protection won't help. Neon
takes I beleve about 65 volts to fire. That's too much for a solid state front
end.

That's true, but the rise time is in nanoseconds and the neon lamp
(or, more appropriately, a gas tube suppressor paired with a high
voltage capaciter, a'la Polyphaser or ICE) will prevent damage from
occurring.

A neon lamp will work for near misses. A gas tube will work better
and more reliably, because the size and shape of the contacts and the
gas mix used will be tailor made for them to fire quickly. Note that
they present a dead short when firing.


Diodes have been used but, unless configured correctly with suitable diodes,
radio noise will be created.

True. You can do it with diodes, but even with recommended ones I've
had problems, so I avoid that approach.

As was recommended -- disconnect the antenna. Only commercial stations need to
keep on a-chugging, and even then they disconnect the antenna, at a stopping
point, and then switch it to a good ground. The protection is for things that
have to remain connected, like emergency frequency receivers.

I still recommend the Polyphaser over disconnecting. The reason? The
polyphaser provides a very low resistance path to ground for the near
miss and/or direct hit you get.

If you just disconnect and leave the coax laying there, you are
opening yourself up to side-flashes. You really don't want to do
that. To REALLY disconnect and be safe, disconnect, put a shorted
connector on your radio, and fasten the coax to copper strap to
ground.

I speak from experience. Since using PolyPhaser I've never had the
slightest problem with lightning. I live in the colorado front range,
and we get lightning here you can't imagine. I also took a direct
strike, once, and other than destroying the coax leading to the
polyphaser, everything was fine.

BTW, I don't know any commercial stations that go off the air for
thunderstorms. Most have hot backups available, though.


Bill, K5BY

--
Eric F. Richards,
"This book reads like a headache on paper."
http://www.cnn.com/2001/CAREER/readi...one/index.html

that might be true, but a close hit can destroy the radio also.

grenner wrote:

If you even feel there may be lightning unplug your antenna from your radio.
It is the only sure way to protect your radio.

Greg
"RJ" wrote in message
...

Years ago ( when I was a young SWL )
my radio antenna was protected with a "lightning arrester".

As I remember it, it was a glass "brick" with three terminals;
ANT; GND; and RCVR
It was filled with neon, so it'd glow with electrical discharge.

I'd like to add lightning protection to my new antenna,
but I'm having a heckova time finding "lightning arresters".

At best, I see listings for "surge protectors".......
and, as I understand it, these are a one-time protection,
which counts on burning out a "mov-diode" for the first strike.
( as for subsequent strikes ???? )

Any sources ?
rj

Check out this site!

http://www.arraysolutions.com/Products/ice/

http://personal.isla.net/ice/

PLENTY of good stuff here!!

73, Mark
------------------------------------------------------------------------

"" wrote:

Years ago ( when I was a young SWL )
my radio antenna was protected with a "lightning arrester".

As I remember it, it was a glass "brick" with three terminals;
ANT; GND; and RCVR
It was filled with neon, so it'd glow with electrical discharge.

I'd like to add lightning protection to my new antenna,
but I'm having a heckova time finding "lightning arresters".

At best, I see listings for "surge protectors".......
and, as I understand it, these are a one-time protection,
which counts on burning out a "mov-diode" for the first strike.
( as for subsequent strikes ???? )

Any sources ?
rj