In a message dated 96-08-08 12:02:21 EDT, you write:
>
> Am planning to build a 2-element wire phased array
> for 40 meters. (It used 1/8-wave spacing, for my 'small'
> lot.) This would have raised radials. My question is,
> has anyone tried building a 2-element antenna
> like this using the "Christman" feed method?
The closest system to the one you described I am aware of actually being
measured was at AM radio station in New Jersey. It has a four tower array
with closer spaced endfire (~1/4 wl) and broadside (~1/2 wl) spacing. When ~
100 ground mounted radials were installed in the system, FS dramatically
improved. FS improvement was quite noticable with the addition of only 30
radials on each tower.
The original system employed six elevated radials at each tower.
Here at my house, a 1/4 wl vertical demonstrated ~5 dB improvement when sixty
radials were substituted for four elevated radials. It made no difference if
the 60 radials were elevated or contacting the soil. Radial height made a big
difference when only four radials were used.
You'll find conflicting data or opinions on this subject since data from
proper single location tests is very scarce. Most of the data circulating,
while sounding impressive, is through long paper trails using FCC FS
estimatation charts.
My suggestion would be to try the small system, and take a FS reading some
distance away in the main lobe. If adding extra radials helps, you might
continue to add them until improvement falls off. Please let me know your
results if you measure (even crudely) FS changes with the number of radials.
73 Tom
>From n6ig@netcom.com (Jim Pratt) Thu Aug 8 18:52:07 1996
From: n6ig@netcom.com (Jim Pratt) (Jim Pratt)
Subject: Gate 2 information
Message-ID: <Pine.3.89.9608081016.A2281-0100000@netcom13>
For those of you curious about when you may request your new CONTEST
callsign via Gate Two of the Vanity Program:
I called the FCC's 800 number today and asked "when"? The lady said she
didn't know and that operators were told to tell people to call back "the
end of August".
I also asked about the rumor that people would be able to request Vanity
Calls via a WWW page. She knew nothing about that either, and
transferred my call to the "webmaster". I have left a message on his
voice mail and, if and when I get a response, I will post it here.
73, Jim N6IG (no, I'm not gonna change it)
n6ig@netcom.com
>From wws@renaissance.cray.com (Walter Spector) Thu Aug 8 04:04:45 1996
From: wws@renaissance.cray.com (Walter Spector) (Walter Spector)
Subject: RFE
Message-ID: <9608081804.AA16056@raphael.cray.com>
DKMC@chevron.com (McCarty, DK 'Dav) asks:
> Would someone knowledgeable please explain the effects of RF exposure which
> the FCC/EPA are trying to avoid? Explain the result of exposure just beyond
> the thresholds which have been set.
I've heard that you can go blind if you do it too much....
Someone I know used the RF exposure argument to prevent a cell
phone company from installing a low tower near his office. His second
floor office would have been too near the panels, given the calculations
and charts in the ARRL Antenna Handbook combined with the specs for the
cell transmitters and antennas, for his comfort. Discussions with the
FCC indicated that the cell company should not have been below 50 feet
and this was clearly being violated. Though not a EE, this fellow is a
competent professional engineer. His arguments were better founded than on
simply asthetic reasons.
The cell company then found a nearby site on a roof about 10 feet over the
heads of resteraunt patrons on an outdoor patio. Despite the complaints of
many, including the resteraunt owner, the city council approved it. I don't
think I want to sit on this patio with multiple 900 mhz transmitters beaming
at me while I drink my coffee...
I've also seen many instances of cell panels pointed directly at apartment
buildings, office buildings, etc. from seemingly a few feet away at the
lot or rooftop next door.
So I think the cell companies bear part of the blame in this situation.
In their zeal to install cell sites *everywhere*, they have given the
impression of 'sneaking' permissive building codes through local
governments and erecting antenna systems, block houses, etc. with little
or no public review.
Walt kk6nr
>From k6km@mail2.quiknet.com (cncnet - Bill Snider) Thu Aug 8 19:14:21 1996
From: k6km@mail2.quiknet.com (cncnet - Bill Snider) (cncnet - Bill Snider)
Subject: Lawyers
Message-ID: <19960808181416.AAA18322@LOCALNAME>
At 10:43 AM 8/8/96 -0400, Tim VE6SH wrote:
>I hope your derogatory comments are not aimed at the many lawyer/amateurs
who volunteer
>their time and services on behalf of the hobby?
>
>Tim VE6SH
Of course not! The term "attack lawyer" and the context are intended to
differentiate. The few attorneys I know personally are, without exception,
truly fine people. Apologies to any "good" lawyers who might be offended.
Bill K6KM
>From gswanson@arrl.org (Swanson, Glenn, KB1GW) Thu Aug 8 20:36:00 1996
From: gswanson@arrl.org (Swanson, Glenn, KB1GW) (Swanson, Glenn, KB1GW)
Subject: ARRL Letter: NEW FCC RF SAFETY STANDARDS
Message-ID: <m0uoZzR-000f5AC@mgate.arrl.org>
This is an excerpt from the August 9, 1996 edition of the ARRL Letter.
While the ARRL does not normally "pre-publish" material, as a service to
the amateur community, I am taking the liberty of posting this to
rec.radio.amateur.misc and placing it on the ARRL Web Page (see
http://www.arrl.org/news/rfsafety/) as soon as it is ready, in anticipation
that it may take a few days for news to percolate to some sites. The Letter
is scheduled to be released tomorrow.
73, Ed Hare, KA1CV,
ARRL Laboratory Supervisor
[And since there is such wide-spread discussion on the reflectors, this is
being posted to the DX and CQ-Contest Reflectors. * Special thanks to the
sysops of these specialized reflectors (DX and Contest) that this is
information being posted to. *
-- A personal note: Hopefully these reflectors can soon return to their
intended
usage. In other words, thanks for the bandwidth. -- 73, Glenn Swanson,
KB1GW.]
The standard notice applies:
The purpose of the ARRL Letter is to provide the essential news of interest
to active, organizationally minded radio amateurs faster than it can be
disseminated by our official journal, QST. We strive to be fast, accurate
and readable in our reporting. Material from the Letter may be reproduced in
whole or in part, in any form, including photoreproduction and electronic
databanks, provided that credit is given to the ARRL Letter and the American
Radio Relay League.
NEW FCC RF SAFETY STANDARDS INCLUDE AMATEUR RADIO
New FCC RF safety standards that become effective January 1, 1997, could
affect the way some hams operate. As a result of a Report and Order adopted
by the FCC on August 1 (ET Docket No. 93-62, Guidelines for Evaluating the
Environmental Effects of Radiofrequency Radiation), Part 97 will require
hams running more than 50 W PEP to conduct routine RF radiation evaluations
to determine if RF fields are sufficient to cause human exposure to RF
radiation levels in excess of those specified. "Measurements made during a
Commission/EPA study of several typical amateur stations in 1990 indicated
that there may be some situations where excessive exposures could occur,"
the FCC said in ending the blanket exemption for Amateur Radio. Amateur
operation at power levels of 50 W PEP or less is "categorically excluded"
from the new requirement in most cases. Where routine evaluation indicates
that the RF radiation could be in excess of the limits, "the licensee must
take action to prevent such an occurrence," the Report and Order stated. The
FCC said this could mean altering operating patterns, relocating the
antenna, revising the station*s technical parameters--such as frequency,
power or emission type--or "combinations of these and other remedies."
Although the new exposure criteria will apply to portable and mobile devices
in general, at this time routine evaluation for compliance will not be
required of devices such as "push-to-talk" portable radios and
"push-to-talk" mobile radios used by Amateur Radio operators. These
transmitting devices will be excluded from routine evaluation.
The FCC encouraged the amateur community "to develop and disseminate
information in the form of tables, charts and computer analytical tools that
relate such variables as operating patterns, emission types, frequencies,
power and distance from antennas." The Commission said it intends to provide
"straightforward methods for amateur operators to determine potential
exposure levels" by year*s end.
"Exactly what is involved in conducting a *routine RF radiation evaluation*
is not yet clear," observed ARRL Executive Secretary David Sumner, K1ZZ,
adding that the FCC has promised to release a revised OST/OET Bulletin
Number 65, "Evaluation Compliance with FCC-Specified Guidelines for Human
Exposure to Radiofrequency Radiation." The League is now studying the
100-plus page docket, to see if the League should seek reconsideration of
any aspects of the FCC decision.
In the Report and Order, the Commission adopted Maximum Permissible Exposure
(MPE) limits for electric and magnetic field strength and power density for
transmitters operating at frequencies from 300 kHz to 100 GHz. These MPE
limits are generally based on recommendations of the National Council on
Radiation Protection and Measurement (NCRP) and, in many respects, are also
generally based on the guidelines issued by the Institute of Electrical and
Electronics Engineers Inc (IEEE) and subsequently adopted by the American
National Standards Institute (ANSI) as an ANSI standard (ANSI/IEEE
C95.1-1992). The Commission used the 1992 ANSI/IEEE standards instead of the
1982 ANSI standards that had formed the basis for the existing rules under
which Amateur Radio stations were categorically exempted.
ARRL Laboratory Supervisor Ed Hare, KA1CV, said the new regulations will
give hams an incentive to demonstrate that Amateur Radio operation is safe.
"Although this means that hams will have to become more educated about RF
safety, most amateur stations are already in compliance with the new
regulations," Hare said.
Sumner said that for certain unusual situations where there is "uncontrolled
exposure" to neighbors and the general public, "amateurs may well have to
make changes in how they operate." The ARRL Lab staff and the RF Safety
Committee are continuing to evaluate the new requirements.
Hare noted that the administrative burden for hams will be minimal, and the
FCC does not require amateurs to submit any documentation to the FCC. "In
essence, the FCC is telling amateurs that if they run more than 50 W, they
need to learn about RF safety and evaluate how this applies to their own
operation," he said.
The new regulations also will require the addition of five questions on RF
environmental safety to the amateur examinations for Novice, Technician, and
General-class elements 2, 3(A) and 3(B). Sumner noted that the Commission*s
Report and Order does not take into account the practical problems
associated with such a significant revision to the volunteer-administered
amateur examinations, and that more time than the Commission has allowed
will be required to do a good job.
The Commission acknowledged the updated guidelines generally are more
stringent than the current rules and are based on recommendations of the
federal health and safety agencies, including the Environmental Protection
Agency and the Food and Drug Administration. The Commission said that the
new rules will protect the public and workers from strong RF emissions.
Adoption of the new rules by August 6 was required by the Telecommunications
Act of 1996.
The Commission also incorporated into its rules provisions of Section 704 of
the Telecommunications Act of 1996 that preempt state or local government
regulation of personal wireless services facilities based on RF
environmental effects, to the extent that such facilities comply with the
Commission*s rules concerning such RF emissions. This preemption does not
directly affect Amateur Radio, however.
The FCC said amateur stations "present an unusual case with respect to
compliance with RF exposure guidelines," in part because they are authorized
to transmit from any place where the Commission regulates the service, as
well as on the high seas, and the FCC does not pre-approve individual
amateur station transmitting facilities and no additional application is
made for permission to relocate an amateur station or to add additional
stations at the same or other locations. The FCC also noted that amateur
stations "vary greatly" from one location to another, transmit
intermittently, and can involve "as many as 1300 different emission
types--each with a distinctive on-off duty cycle." The FCC said most amateur
stations engage only in two-way communication, thus cutting the transmitting
time of any given ham station. "There are many variables, therefore, to be
considered in determining whether an amateur station complies with
guidelines for environmental RF radiation," the FCC said in the Report and
Order.
In comments filed earlier with the FCC, the ARRL strongly opposed adoption
of the new requirements. The ARRL said most Amateur Radio users do not
possess the requisite equipment, technical skills, and/or financial
resources to conduct an environmental analysis. The League has, for several
years, recommended a policy of "prudent avoidance" of exposure to
electromagnetic radiation as a common-sense approach to potential--but not
yet proven--health hazards and against such practices as running high power
to indoor antennas or to mobile antennas that might expose the vehicle*s
occupants. The ARRL also argued that amateur stations, because of their
intermittent operation, low duty cycles, and relatively low power levels,
rarely exceed the 1992 ANSI/IEEE standard. Finally, the ARRL noted that
unlike other radio services, RF safety questions already are included in
amateur license examinations.
The FCC agreed in part. "We concur with the ARRL that amateur operators
should follow a policy of prudent avoidance of excessive RF exposure," the
Commission said. "We will continue to rely upon amateur operators, in
constructing and operating their stations, to take steps to ensure that
their stations comply with the MPE limits for both occupational/controlled
and general public/uncontrolled environments." But the FCC expressed concern
that Amateur Radio operations "are likely to be located in residential
neighborhoods and may expose persons to RF fields in excess of the MPE
guidelines."
For now, the League advises hams not to panic and to read up on the subject.
You can download the complete Report and Order by pointing to
http://www.fcc.gov/Bureaus/Engineering_Technology/Orders/ fcc96326.txt.
Other resources are available on the ARRLWeb page at
http://www.arrl.org/news/rfsafety/.
General information on RF safety is available in the safety sections of the
1996 edition of The ARRL Handbook and in the 15th edition of The ARRL
Antenna Book. These materials offer guidelines on how to comply with the
ANSI standard the Report and Order refers to. Additionally, the ARRL
Technical Information Service offers an information package on RF safety. It
includes a reprint of the Handbook material, an April 1994 QST article by
Wayne Overbeck, N6NB, and a bibliography on the subject. This package is
available for $2 for ARRL members or $4 for nonmembers, postpaid. Nonmembers
should include payment with orders. Contact Bridget DiCosimo, e-mail
bdicosimo@arrl.org or write 225 Main St, Newington, CT 06111. Other
resources are available on the ARRLWeb page at:
http://www.arrl.org/news/rfsafety/.
The ARRLWeb information will be updated as circumstances dictate.
eof
>From seay@alaska.net (Del Seay) Thu Aug 8 19:55:10 1996
From: seay@alaska.net (Del Seay) (Del Seay)
Subject: SprINT contest THIS WEEKEND!!
References: <199608081732.KAA04404@lady.axian.com>
Message-ID: <320A380E.2C6C@alaska.net>
Larry Tyree wrote:
>
> ELEVENTH INTERNET CW SPRINT CONTEST
>
> Contest period: 01:00:00Z to 03:00:00Z on Sunday August 11th UTC. This
> is Saturday evening in the USA.
>
> Bands: 40 and 20 meters only (this is a real radio contest, no internet).
Hi Tree. This should be interesting, because WAE-CW is also this
weekend! See ya' in the qrm de KL7HF
>From p00259@psilink.com (John Dorr K1AR) Thu Aug 8 21:02:58 1996
From: p00259@psilink.com (John Dorr K1AR) (John Dorr K1AR)
Subject: Photo Ops for Quads
Message-ID: <3048616802.0.p00259@psilink.com>
Our roving photo man at CQ is in search mode for cool looking quads (no this
is not a spin-off from my recent experiences with the beast at
WRTC--honest!). If any of you (especially in the East) have such an
animal in the air, please send me a message via return mail.
Thanks...
73 John, K1AR
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