Grounding
for lightning safety
By
Gary
Coffman, KE4ZV
Reasons for grounding a station
You
commonly hear three:
1. to improve RF performance
2. to
eliminate stray RF in the shack
3. to
improve electrical safety.
But in most
circumstances only the last has merit.
(Let's see where the truth is grounded.--AF6S)
1. Improve RF performance
The proposition that a better ground improves RF performance is false except with
antennas that must work against ground. Even then, the ground should be at the antenna feed point, not at the transmitter. (Of course the transmitter can be at the feed point of a
long wire antenna.)
A balanced antenna (dipole, Yagi, or
quad) operates independently of ground. It even works in free space--no
ground connection at ail. The same holds for
a vertical with above-ground radials or a counterpoise.
But many verticals, long wires, and
other symmetric antennas do require grounds--again, best at the feed point.
2. to eliminate RF in the shack
People often give this as a reason for an RF connection to Earth. But,
like taking aspirin for a brain tumor, a shack ground may suppress the symptoms
but do nothing for the underlying problem--which may be a faulty station layout
or design. RF in the shack can result from equipment with poor shielding,
unbalanced feeder currents, or "daisy chained" station
interconnections that create "ground loops."
Grounding
one or more cabinets may even increase the problem. (Though connecting all the
cabinets to a common point, "star wise," usually helps - AF6S.)
be at the feedpoint of a
longwire ante A balanced antenna
(dipole, Yagi, quad) operates independently
Contesting: a
primer for beginners
Lee Zalaznik,
KI60Y
Contesting
can be an adventure-packed weekend of making as many contacts as you could in a
whole year! Contesting has many rewards! For most of us winning is not
everything but making that better score than last year or trying out a new mode
is the thrill. Most contests are faster paced than others and also have
different rules or requirements. If you are getting into contesting, give some
of the smaller SSB and CW contest put on by 10-10 International a try. With the
propagation improving, these sets of contests will be a good way to start
contesting. They take place four times a year. There are two SSB contests in
the winter and summer and two CW contests in the spring and fall. These
contests will give the Amateur Radio operator an ample number of contacts - a
good score and a lot of fun. Check this out at www.tenten.org.
The
next sets of contests are for the more seasoned operator. The IARU contest is a
"work anyone for points" contest with a nice multiplier structure.
Most of the rest of the major HF phone contests are fast-paced such as the
ARRLDXSSB and the ARRL 55 SSB contests. The CVV contests are a notch up in
speed but can be conquered with some practice such as the CQWW DX contests.
The
state QSO parties can be fun! There is always room for another station on the
air from your state.
See Contesting page 7
Maybe
it’s a little early in the year but I thought I would let you know anyway.
Starting in January 2001, or maybe
before CQ de WA2LQO will publish a happy birthday column for its members.
The column will not be over done. Just
happy birthday wishes for our members in the month they were born.
If you do not whish to have your name
and call appear in such a column let me know. If we omit your name and call and
you want your name to appear, let me know.
The Editor, KA2FEA
CQ de WA2LQO
NOVEMBER 2000
VOL. 74,
NO. 11
EDITOR
DAVE ANDERSON, KA2FEA
CONTRIBUTING WRITERS
PAT MASTERSON, KE2LJ
CQ de WA2LQO is published monthly by the Grumman
Amateur Radio Club for its members and friends. Send articles and amateur
equipment advertisements to:
Dave Anderson
Phone (631) 361-8910
ELECTRONIC SUBMISSIONS
If you want to submit
articles or amateur equipment ads via e-mail do the following:
1. For submission direct to
editor call him at above number to set up a transfer.
2. For e-mail transfer:
Internet Address
GRUMMAN
AMATEUR RADIO CLUB OFFICERS FOR 2000
President Pat Masterson KE2LJ B38-111 218-6746
Vice President Gordon Sammis KB2UB C63-005 575-1846
Secretary Peter Rapelje N2PYV Retiree 676-0694
Treasurer Ted Placek KD2UB
1Yr Board Member Zack Zilavy WB2PUE 667-4628
1YrBoard Member Dave Ledo AB2EF
1Yr Board Member Martin Miller NN2C Retiree 423-8153
2Yr Board Member Bill Scheibel N2NFI 924-0126
2Yr Board Member Dan Manfre WA2NDP
Trustee WA2LQO Ray Schubnel W2DKM C31-005 575-5036
STANDING
COMMITTEE CHAIRMEN
Meeting Programs Contact a Board Member
FCC Exam Coord. Bob Wexelbaum W2ILP 499-2214
PRESIDENT’S
PAGE
BY
KE2LJ
"Is it time yet?" People associated with
GARC are beginning to ask me this question more than ever. In the face of the
declining membership of GARC, and all of Ham Radio everywhere, can we keep the
Club alive Or is it time to let it slip away forever? We also have the problem
of lack of support from most of the Company. While there are people in some
areas that still support us, our key helpers from the past are all gone. Those
friends of the Club who are left, are somewhat ineffective in helping us. So,
we need to decide what to do. But, we can put off that painful decision for a
while longer, and I'll tell you why. It's because we still have a few tricks up
our sleeve.
Last week I
was taking my wife for her flu shot, and we were driving east on 25A out of
So, I wondered what Dave would do if he were here
now. And I think I know the answer. Dave would stop talking to the people who
only wanted to keep discussing things. He would go out and make something
happen. This isn't an operating style that's appropriate for everybody, and
maybe not me. But, we are in need of some desperate measures now, and a
different mode may be required. So, let’s try to find a way of replacing all
this talk with some real action. We need to come up with some plan to keep this
Club going, even as the Company fades away. Give it some thought, and hopefully
we can get something going real soon.
As you know,
I was extremely disappointed with the response I got from Bethpage Water to my
request for antenna space on their new water tower. Yes, the tower that
Northrop Grumman gave them $4 million to build! They were very discourteous to
me with their terse reply. I had asked for an informal meeting in which I could
discuss the issues, but I was sent a
curt letter by their lawyer dismissing us with no chance to discuss things. So,
last week I succeeded in having a phone conversation with a Town official. This gentleman was not only aware of Skywarn,
and RACES, but was unhappy to hear of
the manner with which we were treated. He asked me to collect copies of the
letters between myself and the Water people, and forward them to him for
analysis. Of course, he couldn't make any promises, but he will try to help if
he can. So, we are still moving forward in our quest to keep the
But, I am
having less luck getting our trailer moved to a decent site, and the tower
erected. The Company has backed away from a plan to relocate us to a site near
Plt 14. As always, it's a cost issue.
Initially it was about the price for having aircraft warning lights on the
tower. To deal with that, I contacted a Ham friend in the FAA, and he had me
send some maps and paperwork to him. Hopefully, we will get an official FAA
ruling on the necessity of lights. And I'll have lots more to tell you next
time. Well, is it time yet? I don't think so! But ask me again in 6 months. See
you at the meeting!
-Pat KE2LJ
The Castaways
The
original source of this article is unknown, but it was downloaded from the
internet and provided by NY2V.A rather inhibited engineer finally splurged on a
luxury cruise to the
Outside of beautiful scenery, a
spring-fed pool, bananas and coconuts, there was little else. He lost all hope
and for hours on end, sat under same palm tree. One day, after several months
had passed, a gorgeous woman in a small rowboat appeared.
“I’m from the other side of the
island," she said. "Were you on the cruise ship, too?" "Yes, I was, "he answered. "But
where did you get that rowboat?"
"Well, I whittled the oars
from gum tree branches, wove the reinforced gunnel from palm branches, and made
the keel and stern from a Eucalyptus tree."
"But, what did you use for
tools7" asked the man.
"There was a very. unusual
strata of alluvial rock exposed on the south side of' the island. I discovered that if I
fired it to a certain temperature in my kiln, it melted into forgeable ductile
iron. Anyhow, that's how I got the tools. But, enough of that," she said.
"Where have you been living all this time? I don't see any shelter."
"To be honest, I've just
been sleeping on the beach," he said. "Would you like to come to my
place?" the woman asked. The engineer nodded dumbly.
She expertly rowed them around
to her side of the island, and tied up the boat with a handsome strand of hand
woven hemp topped with a neat back splice. They walked up a winding stone walk
she had laid and around a Palm tree. There stood an exquisite bungalow painted
in blue and white.
"It's not much, but I call
it home." Inside, she said, "Sit down please; would you like to have
a drink?" "No, thanks," said the man. "One more coconut
juice and I'll throw up!" "It won't be coconut juice," the woman
replied. "I have a crude still out back, so we can have authentic Pina
Coladas." Trying to hide his
amazement, the man accepted the drink, and they sat down on her couch to talk.
After they had exchanged stories, the woman asked, "Tell me, have you
always had a beard?" "No,"
the man replied, "I was clean shaven all of my life until I ended up on
this island. Well if you'd like to shave, there's a razor upstairs in the
bathroom cabinet.'' The man, no longer questioning anything, went upstairs to
the bathroom and shaved with an intricate bone-and-shell device honed razor sharp.
Next he showered -- not even
attempting to fathom a guess as to how she managed to get warm water into the bathroom
and went back downstairs. He couldn't help but admire the masterfully carved
banister as he walked. "You look great," said the woman. "I
think I’ll go up and slip into something more comfortable." As she did, the man continued to sip his Pina Colada.
After a short time, the woman, smelling faintly of gardenias, returned wearing
a revealing gown fashioned out of' pounded palm fronds.
"Tell
me," she asked, "we've both been out here for a very long time with
no companionship. You know what I mean. Haven't you been lonely, too...isn't
there something that you really, really miss? Something that all men and woman
need? Something that would be really nice to have right now!” "Yes there
is!" the man replied, shucking off his shyness. "There is something
I've wanted to do for so long. But on this island all alone it was just...well,
it was impossible. "Well, it's not impossible, any more," the woman
said. The man, practically panting in excitement, said breathlessly: "You
mean... you actually figured out some way we can CHECK OUR PACKET MAIL
HERE!!??!!”
KN
Grounding from page 1
Sometimes connecting everything to a
good RF ground reduces stray RF at one frequency, but makes it worse at
another.
3. for electrical safety
This
is the best reason for a grounding ! system. An effective grounding system s
can eliminate two different hazards.
Shock hazard
In
the
Lightning
The second reason for effective
grounding is lightning safety--a difficult problem one should approach with
care, because a single mistake can be so costly.
Lightning surges of 8,000 amperes are
common, and occasional "super bolts" reach 200,000 amperes. These
discharges last only microseconds, so their average power is low. In one sense,
fast current rise time, lightning is RF. The fast rise-times mean a lightning
strike can develop kilovolts of potential difference across the inductance of
even a short down lead. If these potentials develop between equipment
cabinets, a strike may destroy you and the equipment's sensitive components.
Single-point grounding Single-point
grounding is a simple concept that can be subtle in execution. All connections
to earth must go directly to a common point, and all connections from equipment
that needs a ground termination must run to that ground point and no other.
Daisy chaining grounds isn't allowed.
Also, every connection to the single
point must be straight, and direct. "Ground busses" are a serious
no-no, though you'll find them touted in Amateur literature. Busses form
instant ground loops. At the currents and rise times in a lightning discharge,
they can allow thousands of volts to develop between equipment cabinets. The
idea of the single-point ground is that it forces everything to the same
potential, that of the single point. And zero lightning-caused potential difference
means zero current flowing through the equipment. Of course the single-point
"ground" itself will not stay at zero volts during a strike. But
that's okay; it's the lightning-caused current and potential differences that
concern us.
Pondering the many "ground"
interconnections in your station, you may conclude that a true single-point
ground is impossible. That's where the concept of the "ground window"
comes in. The ground window is a small metal plate through which every cable
that enters or leaves your station must pass. You bond the wire or shield in
each cable that is supposed to be at ground potential to the plate where it
passes through.
Also, every conductor that is not a
"ground" connects to an appropriate suppression device whose ground
you also bond to the plate. Then you bond the plate itself to the single-point
ground via a heavy, wide metal strap or braid.
The ground window shorts out any large
potential differences that otherwise might develop between cables connected to
various cabinets in your shack. Note that EVERY cable on its way in or out of
the shack must pass through the ground window--including power, telephone,
network cables, antenna feeders, and rotator wires. Allowing just one cable to
bypass the ground window ruins the protection. You can't run an extension cord
to a power outlet that doesn't pass through the ground window.
After you've taken the pains to install a truly protective grounding system, you'll find it makes an excellent RF grounding system too. And you'll be able to stay on the air during the worst thunderstorms, operating your station without the risk of damage or injury.
Proper grounding
isn't magic. It's a welt-understood science more Amateurs should learn about
and apply.
From Nov. ’95 Old Virginia Hams ARC (
KN
The
meeting was called to order by Pat at 6:35 PM. All present introduced
themselves.
TREASURER'S
REPORT -
Ted
was absent so we did not have a treasurers report.
REPEATER
REPORT –
Gordon, KB2UB
Gordon
reported that a new repeater-coordinating group was formed in January, 2000 by
the name of METROCOR. They are taking the place of TSARC. We will wait a few
months to see if they stay in business before registering with them.
Both
of our repeaters are working. Still trying to get in touch with Bill, N2NFI to
go to site.
NET REPORT –
Zak, WB2PUE
The
Sunday 40 Meter Net was great. Today's 20 Meter Net had 3 check-ins. The
Thursday 2 Meter Net has had poor attendance.
VE REPORT –
Bob, W2ILP
Bob
reported that there were 3 VE's present and 1 applicant. He failed the Extra
written test.
WAG REPORT –
Bob, W2FPF
No
Activity
HOUSE REPORT –
Pat, KE2LJ
The
Recreation Department says everything is on hold pertaining to the move of our
trailer and tower to the Plant 14 area. Pat has contacted a friend from the FAA to inquire about the need for a
light on our tower because it is near the Cablevision helipad. He put Pat in
contact with another individual in the FAA who said we must fill out a form and
submit it. He intimated that the FAA does not require lights on towers near
private aviation facilities.
NEW BUSINESS
Two
new members were voted in:
Herman
J Hugo, WA2MJA, Advanced class - Full Member
Barry
Kaufman, WA2B, Extra class - Sustaining Member
Bob,
W2FPF was selected to be Election Chairman.
PROGRAM
Marty,
NN2C was absent, so we did not have a program.
GRUMMAN
AMATEUR RADIO CLUB
MINUTES OF
GENERAL MEETING 10/18/00
By Pete, N2PYV
NETS
Forty
Meters: 7.289 at
7:30 AM EST Sundays.
20 meters: 14.275 at
12 noon Wednesdays.
Two Meters: 146.745 at 8:30 PM EST Thursdays.
145.33
at 8:45 PM Thursdays
145.33 at 9:00 PM EST
Mondays
(ARES/RACES)
VE EXAMS
For information on new VE Exams see write up by Bob, W2ILP
in February newsletter, page 2.
MEETINGS
General
Meetings of the GARC are held on the third Wednesday of each month, at
Melville, at 6:30 PM. All who are interested in Amateur Radio are invited to
attend. Board meetings are held eight days before the General Meeting and GARC
members are invited to attend, but please call Pat Masterson, KE2LJ, at
218-6746 to confirm place and time of meeting
Directions and a map for getting to
the Melville meeting site are available on the Club Web site,
www.qsl.net/wa2lqo.
Contesting from page 2
The
latest equipment and very large antennas are not a requirement to participate
in contests, but a well maintained station with a working transceiver or
separate receiver and transmitter are required. I have had equipment failures
more than once during a contest. Check out the transmitter and receiver before
the contests. Also antennas and feed-lines can get lossy with age. Upgrade or
replace before the contests. Make contacts before the contests to get back in
the groove of operating! Computers have become a fact of life for the Amateur
Radio operator. If you have a computer, use it! It can make life easier! Load,
setup and learn to use your favorite logging software. They all do a good job.
Station layout is important. Think about how the computer keyboard and the rig
are set up and within easy reach.
Techniques
and operating skills are all part of the learning process during a contest.
There are two techniques, search and pounce and calling CQ.
Search
and pounce is going up and down the band and answering stations calling CQ and
making contacts. This is a good technique to get the multiplier numbers up and
work the rare DX. This may be the only way for low power or QRP stations to
make contacts.
Calling
CQ is staying on a single frequency asking stations for contacts. High power
stations can benefit from this technique. I have found that for a low power
station sometimes calling CQ can be a
blessing
or a curse! Stations will not hear me and move on to my frequency and start
calling CQ- I know that it is time to change techniques, bands or modes. To be
productive use a combination of both of these techniques.
If
the contest rules permit, which most do, change bands and rework the stations
on another band or mode! This will not apply to single band contests such as
the 10-10 contest, the ARRL l0-meter or 160-meter contests. Try to work the
highest band possible! Follow the sun - early mornings use 20 or 15 Meters.
Late mornings and early afternoons use 15 and 10 Meters. Early evenings use 15
and 10 Meters. Late evenings use 15 and 20 Meters and then go down to 40 or 80
Meters.
Some
bands may not open up, but keep checking. I have used a logging program to
check which bands I have not worked many stations on, and near the end of the
contest I concentrate on those bands.
For
the contests I work I send in a score. I clear my schedule for that weekend and
work as many hours as possible. This may not be the case for others but in
several hours you can still have tan. To maximize your rate, I would recommend
Friday evenings, Saturday mornings or Saturday evenings picking the bands that
seem open given the propagation.
Contesting
can seem like a solo endeavor. Most contests have a club entry. Check it out!
With some publicity you can get your local club members interested.
Members
can operate the contest and send in their logs along with the name of their
club for a club score. Check out the rules for club scores. Some contests
require a list of eligible members. I did this with the California QSO Party
and
the
Livermore Amateur Radio club.
About
six members joined me in operating and sending in their scores.
Sending
in your score is a personal choice. All contest sponsors want to have all the
people who operate send in their score. Well, go ahead and send in your score.
At least you'll find your call sign in print.
Check
out your favorite contest column for the latest up-coming contests and take the
plunge!
(from
the march, 2000 issue of WorldRadio, Rick McCusker, WF6O ed.)
By Frank Fallon, N2FF ARRL
April 15. 2000
marked an important milestone for Amateur Radio in thc
Many of the new upgraded hams
will now be using the HF bands for the first time, and it appears there will be
a lot of them from reports of crowds at recent VE sessions nationwide. They
will be operating both phone and CW, and some of them won't know what life is like on HF.
They may not realize that one doesn't call CQ on HF by tuning to a quiet spot
and announcing that they're "Listening on frequency." They won't know
much, if anything, about band plans, about nets, about working "up",
or a host of other things. They will need help, just as badly as you and I
needed help when we first went on HF. They
will need to learn things that have never been part of any FCC test. They will
need guidance, not hostility and transferred anger from those unhappy with the
new FCC license structure. Please,
oh please, be generous with your help! Be tolerant of their mistakes and be
friendly and tactful when you offer suggestions for improvement. Please put out the
welcome mat for them. Let them know also when they've done something right, not
only when they've done something wrong. We certainly don’t want a bunch of old
grouches turning them away from ham radio! It's going to be our task to Elmer
them into Amateur Radio. Let's all provide them with a warm ham welcome.