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Date: Mon, 25 Apr 94 01:03:45 PDT
From: Info-Hams Mailing List and Newsgroup <info-hams@ucsd.edu>
Errors-To: Info-Hams-Errors@UCSD.Edu
Reply-To: Info-Hams@UCSD.Edu
Precedence: Bulk
Subject: Info-Hams Digest V94 #455
To: Info-Hams
Info-Hams Digest Mon, 25 Apr 94 Volume 94 : Issue 455
Today's Topics:
Amateur Radio Newsline #871 22 Apr 94
Callserver
CARS
Dangerous RF/Microwave fields
SWR & Power Loss (2 msgs)
Yaesu FT-530 - MANUAL
Send Replies or notes for publication to: <Info-Hams@UCSD.Edu>
Send subscription requests to: <Info-Hams-REQUEST@UCSD.Edu>
Problems you can't solve otherwise to brian@ucsd.edu.
Archives of past issues of the Info-Hams Digest are available
(by FTP only) from UCSD.Edu in directory "mailarchives/info-hams".
We trust that readers are intelligent enough to realize that all text
herein consists of personal comments and does not represent the official
policies or positions of any party. Your mileage may vary. So there.
----------------------------------------------------------------------
Date: Sun, 24 Apr 1994 19:39:33 MDT
From: ihnp4.ucsd.edu!library.ucla.edu!psgrain!nntp.cs.ubc.ca!alberta!ve6mgs!usenet@network.ucsd.edu
Subject: Amateur Radio Newsline #871 22 Apr 94
To: info-hams@ucsd.edu
The electronic publication of the Amateur Radio Newsline is distributed
with the permission of Bill Pasternak, WA6ITF, President and Editor of
Newsline. The text version is edited from the original scripts and
transcribed from the audio reports by Dale Cary, WD0AKO, and is first
published in The Radio & Electronics Round Table on the Genie Online
System.
If you have any comment, suggestion, or news item you would like to submit,
send them via E-Mail to 3241437@mcimail.com or B.PASTERNAK@genie.geis.com.
You can contact Newsline at +1 805-296-7180. It is a combination answering
and FAX machine, if you have a FAX to send, wait for the voice prompt and
press your fax-send button.
All other information and disclaimers are in the text header below.
- - - - - - - -
NEWSLINE RADIO - CBBS EDITION #121 - POSTED 04/23/94
(***************************************************************)
(* *)
(* * * ***** * * **** * ***** * * ***** *)
(* ** * * * * * * * ** * * *)
(* * * * *** * ** * *** * * * * * *** *)
(* * ** * * ** * * * * * ** * *)
(* * * ***** * * **** ***** ***** * * ***** *)
(* *)
(* **** * **** ***** *** *)
(* * * * * * * * * * *)
(* **** ***** * * * * * *)
(* * * * * * * * * * *)
(* * * * * **** ***** *** *)
(* *)
(***************************************************************)
The following is late news about Amateur Radio for Radio
Amateurs as prepared from NEWSLINE RADIO scripts by the staff of
the AMATEUR RADIO NEWSLINE, INC. -- formerly the WESTLINK RADIO
NETWORK. For current information updates, please call
Audio Version of Newsline
=========================
Los Angeles............................ (213) 462-0008
Los Angeles (Instant Update Line)...... (805) 296-2407
Seattle................................ (206) 368-3969
Seattle................................ (206) 281-8455
Tacoma................................. (206) 927-7373
Louisville............................. (502) 894-8559
Dayton................................. (513) 275-9991
Chicago................................ (708) 289-0423
New York City.......................... (718) 353-2801
Melbourne, FL.......................... (407) 259-4479
Electronic Hardcopy Version of Newsline
=======================================
GEnie (RTC Bulletin Board)............. m345;1
GEnie (File Library)................... m345;3
Dallas Remote Imaging BBS (DRIG)....... (214) 492-7573
In bulletin number 36
The Midwest Connection BBS............. (701) 239-2440
In bulletin number 6 of the ham radio conference
Delphi.................................
In the ham radio conference
Internet...............................
In the rec.radio.info newsgroup
FTP: oak.oakland.edu, file: pub/hamradio/docs/newsline
Fidonet, RIME, Intellec, I-Link........
In the Ham Radio conference of those networks
For the latest breaking info call the Instant Update Line listed
above. To provide information please call (805) 296-7180. This
line answers automatically and will accept up to 30 minutes of
material.
Check with your local amateur radio club to see if NEWSLINE
can be heard weekly on the air in your area.
Articles may be reproduced if printed in their entirety and
credit is given to AMATEUR RADIO NEWSLINE as being the source.
For further information about the AMATEUR RADIO NEWSLINE,
please write to us with an SASE at P.O. Box 463, Pasadena, CA
91102.
Thank You,
NEWSLINE
(****************************************************************
Some of the hams of NEWSLINE RADIO...
WA6ITF WB6MQV WB6FDF K6DUE W6RCL N6AHU N6AWE N6TCQ K6PGX N6PNY
KU8R N8DTN W9JUV KC9RP K9XI KB5KCH KC5UD KC0HF G8AUU WD0AKO DJ0QN
and many others in the United States and around the globe!!!
(****************************************************************
[871]
The following is a QST
Can a new Fairness Doctrine impact on ham radio and will the
ARRL get its way on vanity call signs? Find out on Newsline
report number 871!
(*****
HAM RADIO AND THE FAIRNESS DOCTRINE
Bowing to extensive White House demands, congress is again
pressuring the FCC to reinstate the "fairness doctrine" and to
expand it past its original intent. Because of the latter some
hams want Amateur Radio discussion groups included. Heres the
story.
The fairness doctrine was an FCC regulation repealed in 1987
which required broadcasters to air both sides of a controversial
issue. According to a report in the trade publication Daily
Variety, a Federal Communications Commission staffer confirmed the
agency is getting "heat" from Capitol Hill on the issue, although
the aide would not identify the lawmakers involved. Radio -
Television News Directors Association president David Bartlett
asserts that the pressure is coming from Rep. John Dingell.
Dinghall is the powerful Democratic chairman of the House Energy
and Commerce Committee and is believed to be acting in concert
with the president and his staff.
Not reported in Variety is a strange Amateur Radio connection
in all of this. It now seems that several hams involved in long
running 75 and 20 meter debate net activities believe it is
important to include on-the-air amateur Radio discussions under
the terms of any new Fairness Doctrine. Anyone listening above
3850 KHz or 14.300 MHz is already aware that this small but vocal
group of hams feel that they have a constitutional right to have
their views on various issues known to all of Amateur Radio using
their ham stations as a broadcast platform. Some are already
believed to be lobbying their local congressional representatives
for inclusion of private radio service communications in any new
Fairness Doctrine legislation.
In 1987, the FCC under then-chairman Dennis Patrick repealed
the fairness doctrine on grounds that it could no longer be
justified in an era of cable TV and other burgeoning media
outlets. A congressional effort to codify the regulation died
when proponents failed to muster enough votes to override
President Reagan's veto.
Most congressional observers expected Congress would easily
reinstate the rule following the election of President Clinton in
1992. But the effort died last year after Rush Limbaugh and other
radio talk show hosts engineered a well-organized effort to kill
the proposal. If the Fairness Doctrine is ever reinstated, the
inclusion of Amateur Radio and other personal communications
services is doubtful because none fall under the purview of any
broadcast related FCC rules. But that does not seem to be enough
of a reason to convince proponents of including ham radio
communications in a new Fairness Doctrine from trying. Stay
tuned. This one is not over yet.
(*****
FELDMAN RESPONSE
Over the past several weeks Newsline has reported on legal
action by Southern California's Claremont Amateur Radio
Association to bar several radio amateurs from the clubs
repeaters. One of the people who was the target of a CLARA
restraining order is Drew Feldman, N3KSO. Newsline had the
opportunity to talk to Feldman to get his perspective on the legal
action taken against him. The comments that follow express
Feldman's point of view.
Interestingly Feldman is not as upset with the Clarmont Amateur
Radio Club as he is with the attorney that is representing the
organization, Sid Radus, N6OMS.
"The first order of business of Southern California's Repeater
Coordinating Committee was to close a repeater that had been
coordinated open going on two decades. The repeater, high level,
blanketing most of southern California with great coverage was
originally coordinated properly open. But with no consideration
for its large user group, its own rules, the FCC guidelines, no
notice of this action was taken by Sid Radus, the new TASMA
President. This is the same Sidney Radus that brought hams to
court in an attempt to control the user group of the very same
machine. A conflict of interest is obvious. I'm one of two
amateurs that as of late has been caught up in this mess. There
have been three cases prior, and I know of two more scheduled in
the near future." Drew Feldman, N3KSO.
Obviously Feldman's point of view differs from that of the
Claremont Amateur Radio Club and is members. He is aware of the
mistake made by the court in accepting an older version of section
97.113 in denying a change of venue request. Its now up to him
and Anthony Cardines, WA6IGJ to go forward with any appeal.
A more in-depth interview with N3KSO has been conducted by RAIN
Producer Hap Holly, KC9RP. That report will be on the RAIN
Dial-Up in a few weeks.
(*****
CANADIAN AMATEUR RADIO REALIGNMENT
What would you say if you learned that the FCC was going to
delegate the overall administration of the United States Amateur
Radio Service to the American Radio Relay League, the National
Amateur Radio Association or maybe even Sears Roebuck? You would
probably be more than a bit shocked. So imagine the way hams in
Canada must be feeling after learning that the Canadian government
and the national society Radio Amateurs Canada have formed a
working group aimed at turning the administration of the Canadian
Amateur Radio Service over to the national society.
According to Fred Maia's W5YI Report, if the details are worked
out and approved by Parliament, Radio Amateurs in Canada could
wind up managing the certification and documentation of all
aspects of the service, the examination and licensing of all
applicants for ham radio licenses and overall control of the
Amateur Radio spectrum within Canada and its possessions. In
fact, word out of Ottawa is that the government is even
considering delegating every aspect of the Canadian Amateur Radio
service to Radio Amateurs of Canada. This would give the RAC wide
ranging pseudo government powers to maintain examination
questions, approve amateur service examiners, issue call signs and
perform Amateur Radio spectrum surveillance to assure that all
Canadian hams were abiding by the service rules. Such an
agreement would also give the Radio Amateurs of Canada exclusivity
in the publishing and distribution of all documents related to the
Canadian Amateur Radio service.
The working group is expected to take at least a year before
it arrives at any definitive agreement. If an accord can be
reached it could set an example that other nations may emulate,
worldwide.
(*****
ARRL DEVELOPS VANITY CALL PROPOSAL
The ARRL's Executive Committee has approved the recommendations
of the Ad Hoc Committee on Preferred Call Signs in preparation for
the ARRL's filing of formal comments in PR Docket 93-305, the
FCC's Vanity call sign proposal.
The committee report says that all amateurs should be eligible
for participation in the program. A phase-in period and priority
system of what the League calls gates should be adopted to allow
the Commission relief from the administrative burden expected from
the heavy initial submission of applications, and to afford
licensees the opportunity to regain lost call signs. Included in
the first gate would be those who wish to obtain the call sign of
a direct family member. Clubs with lapsed club licenses and call
signs should be allowed to recoup those call signs in the first
priority group. The second gate in the priority system would be
opened to Extra Class licensees; a priority third gate would be
opened to Advanced Class licensees. The League says it will also
recommend that one by one prefix call signs be made available for
limited duration special events that are of national significance.
The April 6th recommendations were based on membership input
solicited by the committee. A copy of the committee's complete
report is available for an SASE from the Regulatory Information
Branch at League Headquarters, and on electronic services
including CompuServe, America On Line, Prodigy, and the ARRL
Bulletin Board.
(*****
ARRL SEEKS CLUB CALL SIGN RULING
The ARRL has also petitioned the FCC to increase the minimum
number of members necessary for granting a club station license
from two to four. The League says that the FCC's 1993 notice of
proposed rule making to reinstitute club licensing makes this a
timely issue.
In 1990, the League, as part of a petition for rule making
seeking miscellaneous changes in the Amateur Service Rules,
proposed the same change. At the time, no club station licenses
were being issued, but the League said that if that program was
resumed, the two-person criteria would invite applications from
parties that are not clubs, such as two or three licensees simply
wanting an alternative call sign.
The League believes that the two-person criterion is
insufficient to distinguish bona fide clubs from two or three
individuals who do not function as a normal Amateur Radio club.
By way of example league says that of 1,957 Amateur Radio clubs
that are ARRL-affiliated, only 10 have fewer than four members.
Until 1976, the FCC required an application for a club station
license to file copies of the club's constitution and bylaws,
which helped ensure that the club was bona fide. But the FCC has
not issued club station licenses since 1979. So the commission
declined to change the criteria, since new club licenses were not
being issued.
The Leagues request has designated as RM-8462.
(*****
ARRL BEGINS LICENSE RENEWAL SERVICE
The ARRL has now begun mailing amateur radio license expiration
notices to its members. The notices, including an envelope
addressed to the FCC's processing facility in Gettysburg, PA, are
sent 90 days before the license expiration date and are generated
from the official FCC database. All addresses are being cross
checked with the ARRL membership database and the QST magazine
mailing address is used if it is different from the address in the
FCC database. This the League says is being done for both
accuracy and to insure prompt delivery.
(*****
SHACK AND THE HAMVENTION
Now for an update on next weeks Dayton Hamvention starting
with word that Radio Shack for the first time ever it is
recognizing this very popular ham radio event. An advertisement
page 22 of the latest Radio Shack flyer heralds a banner
proclaiming "Dayton Hamvention Ham Convention Specials." It also
invites readers to --and we quote -- "Plan to visit the worlds
largest and most famous Ham gathering, the Dayton Hamvention with
its Giant Flea market, exhibits and activities for the family
taking place April 29, 30 and May 1 at the HARA Arena, Dayton
Ohio." Radio Shack also offers their popular 2 meter and 70 cm
hand-held FM transceivers at substantial savings off their usual
prices.
(*****
PACKET CLUSTER DESIGNER TO RECEIVE AWARD
One ham who is definitely going to be at next weeks Dayton
Hamvention is Dick Newell, AK1A. Newell and his Packet Cluster
software have become a staple on the VHF and UHF bands worldwide.
As a result Newell is the winner of this years Dayton Amateur
Radio Associations Technical Achievement Award.
Mr. Newell is being recognized for his efforts in amateur radio
through the creation of the packet cluster concept. As well as
the software that supports it. AK1A first started working on the
packet cluster concept in 1986.
"I designed the protocol to talk, to hook these computers up
together. They exchange information with each other and send what
nodes that are connected to each station, which users are
currently connected to the system. And then when somebody does an
announcement or DX spot it gets distributed to each node. Then
the node is responsible and the software sends it to all the users
that are locally connected to that node." Dick Newell, AK1A.
Packet cluster has grown from just a small number of computers
linked together.
"The number of amateurs that use packet cluster all the time is
probably between 35,000 to 40,000 amateurs." Dick Newell, AK1A.
Mr Newell was humbled and surprised by the award.
"I was completely surprised, I had no idea that I was even
being considered. I consider it a very big honor. That is all I
can say. I was very surprised." Dick Newell, AK1A.
Dick Newell, AK1A will receive the 1994 Technical Excellence
Award at the Grand Banquet to be held Saturday evening, April the
30th at the Dayton Convention Center located in downtown Dayton.
(*****
FM-RPT
"The World of FM and Repeaters" is a new monthly column by
Newsline producer Bill Pasternak, WA6ITF premiering in the May
issue of Worldradio News. According to Pasternak, he was enticed
into writing the column after it was pointed out to him that no
publication other than QST Magazine was devoting any regular
page-space to the largest sub-group within the United States
Amateur Radio service.
Pasternak says that the Worldradio FM and repeater column will
not be a rehash of his old "Looking West" that ran 22 years in 73
Magazine. Instead Bill says that he will use the world-wide news
gathering potential of Newsline to procure timely information that
is vital to the day to day on-air operations of all FMers,
repeater licensees, system owners and repeater users. The column
will also solicit original articles and papers from prominent
FMers, repeater groups and frequency coordination councils. You
can meet Bill at the Worldradio News booth at next weeks Dayton
Hamvention. He will also be hosting two forum sessions at
Hamvention '94 as well.
(*****
TONY ENGLAND, W0ORE TO SPEAK AT QCWA DINNER
Former NASA Astronaut Tony England, W0ORE, will be the keynote
speaker at the Southwest Ohio QCWA dinner in Dayton, Ohio on
Friday, April the 29th. The event also takes place Hamvention
weekend at the Continental restaurant which is located about a
half mile west of Interstate 75 on State Route 725. The dinner
gathering begins at 7:30 PM.
(*****
RUSSIAN TIMES
The Russians are really taking to electronic mail in a big
way. The March 9 New York Times notes in a story that Russians
are taking to e-mail in a big way, some of them even being able to
access the Internet. "We can use the Library of Congress in five
minutes, while it takes a magazine from the US three months to
reach Russia," a Russian scientist said.
(*****
DX
In DX, word that the Radio Society of Great Britain has
scheduled its 1994 International HF and Islands on the Air
Convention for October 7 to 9, 1994. Included this year is a 30th
birthday party for IOTA. The convention will be held at the
Beaumont Conference Centre in Old Windsor, Berkshire. More than a
dozen speakers already have signed on, including Peter Casier,
ON6TT, one of the 3Y0PI Peter I Island expedition operators, and
Roger Western, G3SXW/ZD9SXW. For more information, contact E. N.
Cheadle, G3NUG, Further Felden, Longcroft Lane, Felden, Hemel
Hempstead, Herts HP3 0BN.
(*****
VANITY CALLS
When amateur radio operators get the go-ahead to request vanity
callsigns... one radio club already has a particular call sign in
mind. Members of wars -- West Alabama Amateur Radio Society, will
ask the FCC to grant W4WYN as the club's new call sign. It's the
Club's way of paying tribute to a special amateur radio operator:
Don McDaniel. McDaniel was a driving force in amateur radio in
Tuscaloosa, Alabama, for many years. He was a close friend of
many wars members -- and was very active in public service. In
fact, McDaniel was always one of the first to volunteer, any time
emergencies arose. WARS members say having W4WYN as their club
call sign would be a fitting tribute to Don McDaniel... an amateur
radio operator admired by all who knew him.
(*****
And for this week, that's all from the Amateur Radio Newsline.
You can write to us at Post Office Box 463, Pasadena, CA 91102.
Next week a full report on planned activities at Hamvention 94.
Please check it out.
(* * * Newsline Copyright 1994 all rights are reserved. * * *
--
< ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^>
< "Big Steve" Coletti >
< Shortwave Listener, Broadcaster, Computer Consultant >
< and all around nice guy >
< Internet: bigsteve@dorsai.dorsai.org ==== S.COLETTI2@genie.geis.com >
< UUCP: steve.cole@islenet.com ==== steveny@lopez.marquette.mi.us >
< Fidonet: 1:278/712 US Mail: P.O. Box 396, New York, NY 10002 >
< Voice: +1 212 995-2637 >
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
------------------------------
Date: 25 Apr 94 06:41:26 GMT
From: news-mail-gateway@ucsd.edu
Subject: Callserver
To: info-hams@ucsd.edu
The callserver that I have found to have the lastest database (~NOV 93) is
Telnet to pc.usl.edu port 2000
This will get you there direct, type help for on-line commands...
--
#############################################################################
#Talk to ya, Dave "Hey, hey, soldier, where ya goin' to?" #
# "Going to the U.S. Army Airborne School!" #
#Michigan Tech University "Hey soldier don't y'know Benning is hot?"#
#(where it's too @#*! cold!) "And Sergeant Airborne'll dog ya a lot!" #
#dmgillah@mtu.edu "I ain't gonna whine, I ain't gonna beg," #
#KB8POR@W8YY.#upmi.mi.usa.na "I'm just tired of bein' a stinkin' leg!" #
#############################################################################
------------------------------
Date: Sun, 24 Apr 1994 01:57:42 GMT
From: ihnp4.ucsd.edu!swrinde!sgiblab!wetware!spunky.RedBrick.COM!psinntp!psinntp!pool!utdp@network.ucsd.edu
Subject: CARS
To: info-hams@ucsd.edu
I would like to know what cars don't like ham radio equipment....the following
I am considering purchasing:
Saturn SL@
Saturn SL2
Escort GT
Dodge Shadow
I have heard of car coimputers going wild when operators key their mike
--
/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\
Tom Prohigh (utdp@sunyit.edu or tom0624@aol.com) /N2SXR call sign \
\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/
------------------------------
Date: 25 Apr 1994 02:56:05 -0400
From: ihnp4.ucsd.edu!agate!howland.reston.ans.net!europa.eng.gtefsd.com!news.ans.net!hp81.prod.aol.net!search01.news.aol.com!not-for-mail@network.ucsd.edu
Subject: Dangerous RF/Microwave fields
To: info-hams@ucsd.edu
In article <kludgeCopwDJ.CEI@netcom.com>, kludge@netcom.com (Scott Dorsey)
writes:
>Does anyone know what is considered dangerous RF and Microwave signals.
>Somehow I remember that between 100K and 30GHz your not suppose to expose
>human's to more than 194V/meter (the spec could have been either an ANSI,
>IEEE, or OSHA spec).
Unfortunately I don't recall the precise spec, but there is a current ANSI
limitation that is frequency selective, specified in both mW/cm2 and V/m. I
believe it's ANSI C95.1 (1992). An article referring to same appeared in the
last two years of the Proceedings of the IEEE (sorry for the precision, but I
can't find the article in my pile of xeroxed stuff!)
The old OSHA standard was 194 V/m (which translates to 10mW/cm2 FAR FIELD),
frequency independent. That spec was revised to correspond with the human
bodies increased absorption of EMag between 300MHz and 3 GHz. In some cases
(if memory serves) the new spec is 20 dB more stringent than the old.
nx7u@aol.com
------------------------------
Date: Mon, 25 Apr 1994 03:47:40 GMT
From: ihnp4.ucsd.edu!usc!howland.reston.ans.net!gatech!kd4nc!ke4zv!gary@network.ucsd.edu
Subject: SWR & Power Loss
To: info-hams@ucsd.edu
In article <2pf3ma$f16@bones.et.byu.edu> haymoree@newt.ee.byu.edu (Ed Haymore) writes:
>Here's a question that's been bothering me for some time -- an article
>in April's QST reminded me of it.
>
>This article, and other material I've seen, pooh-pooh the idea of a low
>SWR. (Maybe I should preface this by saying I'm not a 1:1 SWR fanatic,
>though. :-) These articles say that as long as you have low-loss cable,
>most of the energy bouncing back and forth between the transmitter and
>the antenna ends up going out the antenna anyway.
>
>My question is: since the transmitter is matched to the line, why does
>the reflected energy coming from the antenna get reflected again at the
>transmitter? Why isn't it all (or mostly) absorbed in the finals?
The finals are not a *load*. The line is matched to the final's "load
line" which is a mathematical fiction used to describe the device's
*output* impedance. That impedance is simply E/I for the stage. It's
not a resistor. The transmitter is a source, not a sink. Consider a
fire hose, try spitting *into* an operating fire hose. How much of
your spit gets flung right back in your face?
Gary
--
Gary Coffman KE4ZV | You make it, | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems | we break it. | uunet!rsiatl!ke4zv!gary
534 Shannon Way | Guaranteed! | emory!kd4nc!ke4zv!gary
Lawrenceville, GA 30244 | |
------------------------------
Date: 25 Apr 1994 03:11:15 -0400
From: ihnp4.ucsd.edu!agate!howland.reston.ans.net!europa.eng.gtefsd.com!news.ans.net!hp81.prod.aol.net!search01.news.aol.com!not-for-mail@network.ucsd.edu
Subject: SWR & Power Loss
To: info-hams@ucsd.edu
In article <1994Apr25.034740.8791@ke4zv.atl.ga.us>, gary@ke4zv.atl.ga.us (Gary
Coffman) writes:
>This article, and other material I've seen, pooh-pooh the idea of a low
>SWR. (Maybe I should preface this by saying I'm not a 1:1 SWR fanatic,
>though. :-) These articles say that as long as you have low-loss cable,
>most of the energy bouncing back and forth between the transmitter and
>the antenna ends up going out the antenna anyway.
>My question is: since the transmitter is matched to the line, why does
>the reflected energy coming from the antenna get reflected again at the
>transmitter? Why isn't it all (or mostly) absorbed in the finals?
Well it depends. The precise scenario you describe is correct (I believe)--if
the final amp is really Z0 ohms output feeding a transmission line of z0 ohms
characteristic impedance, then any reverse travelling wave sees no mismatch at
that junction, and that power is absorbed by the amplifier and essentially
converted to heat.
Which would explain why your fan on that solid-state rig runs harder when
you're delivering into a crappy load :-)
If there is a tuner involved it's a different story. The tuner establishes a
conjugate match at the amp/line junction, so there *is* a mismatch there.
Reflected energy re-reflected from the amp/line junction, and any power not
reflected is again dissipated in the amp as heat. The point of the conjugate
match is to insure that the re-reflected voltage appears essentially in phase
with the original incident voltage to maximize the power transfer.
The problem with using the tuner at the TX output is that the SWR of the line
can cause additive heat losses in the coax beyond the nominal dB/100'
specification. This occurs because at current peaks in the standing wave on
the coax, there's more I2R loss. Although the SWR has to get pretty high (like
10:1) for this phenomenon to have much effect.
------------------------------
Date: 25 Apr 1994 02:29:33 GMT
From: ihnp4.ucsd.edu!swrinde!gatech!newsxfer.itd.umich.edu!news1.oakland.edu!vela.acs.oakland.edu!prvalko@network.ucsd.edu
Subject: Yaesu FT-530 - MANUAL
To: info-hams@ucsd.edu
1) Dial in the freq you want to memorize.
2) hit the FUNC button
3) use up/down button or the tuning knob to select a memory channel
4) hit the MR button.
the rig will also store power info, rpt offset, and PL freqs.
opps.
vi and I don't get along.... 73 wb8zjl
------------------------------
End of Info-Hams Digest V94 #455
******************************