ISSUE
NO.
75
September, 1989
Send A Message To The League!
Last month, we outlined a plan of
action for a unified effort to
petition the FCC to follow through on its stated promise to reconsider
the AM power issue before the scheduled power reduction for AM goes
into effect next June.
Our first step is to attempt to get
some kind of ARRL support.
Headquarters officials have repeatedly denied any anti-AM bias and
claim to be sympathetic to our cause, but we are reminded that it is
the Board of Directors that determines ARRL policy. In the past,
Directors have claimed to have heard very little from members in their
Divisions in support of AM, and therefore have felt that this issue is
of little importance. In addition, we have to make a lot of noise,
because we have to compete with other issues for League officials'
attention. They have recently been preoccupied with the 220 mhz
situation, no-code, etc.
All AMers who are League members are
urgently requested to write to
your Division Director and ask for League support in the AM power
issue. Letters should not be negative, hostile or overly critical of
the League, but firm, positive and based on clear logical reasoning.
Letters badmouthing the "slop buckets", "rice boxes" and "appliance
operators" will surely backfire, since chances are overwhelming that
your Director operates SSB with imported commercially built equipment,
and does not own a homebrew transmitter.
In this article we have included a
sample letter to help give our
readers some ideas. It is a copy of an actual letter recently sent to
the Delta Division Director. For maximum effectiveness, read the sample
letter, think about the issues involved, and compose your own letter in
your own words. If you lack the time or inclination to compose your own
message from scratch, you may closely borrow from this sample, but at
least change some of the wording, or better still, think of something
that was left out and include that in your letter. Individualize your
message as much as you can; don't expect a bundle of identically worded
"form letters" to be taken very seriously by the Divison Directors or
other League officials.
To find out who your Division
Director is, look on page 8 of any recent
issue of QST. Each Division is listed by state or geographical region.
Once you have determined your Division, you will find the name, address
and phone number of the Director and the Vice Director listed to the
left.
Just as this issue was going to
press, it was learned that Directors
and Vice-Directors are up for election in six Divisions. Ballots have
already been mailed to members, and must be returned by noon, November
20. This gives the AM community an excellent opportunity to bring up
this issue not only to present Directors, but also to the candidates
for election. It will be the newly elected Directors who will attend
the January Board Meeting where major ARRL policy decisions will be
made.
According to one candidate, in the
last Delta Division election only
about 1900 out of a possible 7500 eligible members voted - about 25 per
cent. Because of low participation in these elections, an active AM
community could have an impact - possibly deciding the outcome of a
close race! Drop these candidates a line, or Xerox a copy of the letter
you are sending your present Director, and let them know you plan to
vote, and that you will decide after hearing from all the candidates
concerning this issue. The names, addresses and callsigns of all
candidates up for election are listed at the end of this article.
(Web editor’s note: addresses and
phone numbers have been removed; this
article is from 1989.)
Sample Letter To
ARRL Division Director
Joel M. Harrison
(Callsign and address redacted)
Dear Mr. Harrison:
I recently attended the forum
presented by Dave Sumner at the
Huntsville Alabama hamfest. One of the points Mr. Sumner made clear was
his assurance that the League is opposed to any further loss of
existing privileges presently enjoyed by amateurs. I am writing to
remind you that, in addition to the highly publicized loss of 220-222
mhz, still another loss of existing amateur privileges is scheduled by
the FCC to take effect in less than a year.
The amateur radio power limit was
changed in July, 1983, under Docket
82-624, from the longstanding 1000 watts input to the final, to 1500
watts p.e.p. output from the transmitter. Since the peak-to-average
power ratio differs widely for the various modes of emission permitted
under Part 97, the actual power limit was substantially changed for
most of the modes used by amateurs.
The maximum operating power for SSB
phone was essentially unchanged,
while the limit for CW, FM and certain other modes was approximately
doubled. However, the power limit for AM phone (A3E emission), because
of a quirk in the mathematics of modulation theory, was reduced to
one-half the power level permitted under the old rules. The FCC
realized this was in reality a loss of amateur privileges, so in order
to reduce the "immediate impact" of the ruling, a "grandfather clause"
was included in §97.313 (b) to allow AM phone to operate under the
original power standard until June 2, 1990.
In Paragraph 6 of the Report and
Order of Docket 82-624, the FCC
acknowledged that the most significant concern expressed in the
comments was the effect the proposal would have on AM operations, and
committed itself to review this matter before the power reduction
actually goes into effect. "...We, therefore, have decided to limit the
grandfather provisions to a period ending June 1, 1990. If it appears
there is any justification to do so, we will reconsider the matter at
that time."
Since 1983, we have seen a
substantial increase in the popularity of
AM, as rendered evident not only by AM activity heard daily on specific
portions of the 160-metre and HF bands where most AM operators
voluntarily confine their operations, but also by the fact that most
multi-mode amateur transceivers on today's market include AM transmit
capability. The fact that there is substantial interest in this mode,
and the fact that the stated purpose of the FCC's power rule proceeding
(a safe and unambiguous measurement of transmitter power level) can be
served without taking away any existing privileges or making any
amateur equipment obsolete, constitute sufficient justification for the
FCC to reconsider this matter before next June.
As a longtime AM phone enthusiast, I
am asking for the League's help in
persuading the FCC to honor its commitment and rescind this unfair
power limit reduction for which AM has arbitrarily been singled out. My
suggestion is that the League work up an iron clad technical definition
paragraph to replace the existing §97.313(b) grandfather clause",
and prepare a well-thought-out rulemaking petition to FCC in time for
consideration before June, 1990. Possible approaches include (a) making
the existing grandfather clause permanent, (b) defining the output
power for A3E in terms of carrier output rather than p.e.p., or (c)
determining an appropriate p.e.p. output limit for A3E that would be
approximately equivalent to the maximum legally attainable at present
under the grandfather provision.
I wish to re-emphasize that AM
operators are not asking for a "power
advantage" over other modes, or special privileges of any kind. We are
merely seeking to retain privileges we enjoy at the present time, which
have existed for over seven decades.
The FCC argues that the 3 dB power
reduction for AM would be
"insignificant in terms of actual communications effectiveness."
Experience has shown this not to be true, particularly on 160 metres
where much of the AM activity takes place. High summer static levels
and man-made electrical noise plague this band, and every available dB
of signal often counts in overcoming the noisy conditions that prevail.
Also of concern would be the expense of modifying existing 1000-watt
transmitters to comply with the new regulation. This could require
replacement of the costly plate transformer and/or extensive alteration
of the RF output and modulator circuitry.
I am aware that the Communications
Act requires the use of minimum
power necessary to maintain desired communications. This applies to all
modes in precisely the same way, and has no special application to AM.
Despite the well-known communications effectiveness of CW, the CW power
limit was at least doubled under this preceding. If this substantial
power increase for CW could be reconciled with the minimum-power rule,
then merely maintaining the existing power limit for AM would not be
inconsistent with the same requirement.
I am certain I am speaking for many
AM operators who are also League
members, when I urge the League to actively attempt to dissuade the
Commission from implementing an arbitrary reduction in amateur
privileges, which cannot be shown to serve the public interest, or the
interests of amateur radio, in any way whatever.
Can we count on your support in this
matter?
Cordial 73,
(signed) Donald Chester, K4KYV
cc: Vice Director
Joseph A. Butler
Dave Sumner
The AM Press/Exchange
Candidates For
ARRL Director and Vice
Director Elections
The ARRL Elections Committee has
completed its examination of
nominating petitions for Director and Vice Director for two year terms
of office beginning January 1, 1990. Ballots were ordered mailed to
full members in six Divisions, as follows. For the convenience of
readers who wish to contact these candidates, their names, callsigns
and mailing addresses are listed below. (Addresses redacted)
ATLANTIC DIVISION
For Director:
Hugh A. Turnbull, W3ABC
Robert B. Weinstock, KN1K
For Vice Director:
Kay C. Craigie, KC3LM
James M. Mosley, W2BCH
DAKOTA DIVISION
For Director:
Richard P. Clem, W0IS
George E. Frederickson, KC0T
Howard B. Mark, W0OZC
DELTA DIVISION
For Director:
Arthur P. Kay, W5APX
Joel M. Harrison, WB5IGF
For Vice Director:
James A. Amundson, W5TRD
Henry R. Leggette, WD4Q
John M. Wondergem, K5KR
GREAT LAKES DIVISION
For Director:
Leonard M. Nathanson, W8RC
Allan L. Severson, AB8P
MIDWEST DIVISION
For Director:
Paul Grauer, W0FIR
Robert S. McCaffrey, K0CY
For Vice Director:
Lyndell C. Miller, WA0KUH
Laurence S. Staples, W0AIB
SOUTHEASTERN DIVISION
For Vice Director:
Evelyn D. Gauzens, W4WYR
Alan H. Page, KE4WO
open forum
Editor, AM
Press/Exchange:
Attached is a copy of the petition I
will be circulating several copies
of within the Rocky Mountain Division. While there are probably
numerous ways to state the same thing, my point is that AM operators
have been shafted by the Commission without a word of protest by the
League. I want EVERY Director to feel some heat before the next board
meeting, and, while not replacing individual letters of concern, a
petition is probably the easiest and quickest way for the average
amateur to participate. I suggest that someone from each of as many
divisions as possible take it upon himself (i.e.--volunteer his time)
to handle the responsibilities within their particular division, and
forward copies of the signed petitions to their Director. Think you
..... or someone else could coordinate things on a division by division
basis?? I can be reached by mail or at (phone number redacted).
Best Regards,
(signed) Bill, KD0HG
PETITION FOR URGENT ACTION BY THE
AMERICAN RADIO RELAY LEAGUE
To: ________________________
Director, ARRL _______________________
Division
The FCC has recently mandated a 50%
reduction in the maximum power
allowed by Amateur stations utilizing double sideband with carrier (AM
radiotelephone) emissions, effective on June 2, 1990. This is yet
another in a recent series of FCC actions, generated by Washington
bureaucrats, that have taken away or restricted Amateur frequencies and
other formerly held privileges. The League has not taken any action on
behalf of the Amateur community on this issue.
We, the undersigned, request that the
AM President and Board of
Directors demonstrate their commitment to representing ALL Radio
Amateurs by directing the League's Legal Counsel to take whatever
actions are required before the FCC or other governmental agencies to
restore the AM radiotelephone power limit to 1 Kilowatt DC input on a
permanent basis.
SIGNATURE
NAME
(PRINTED)
CALLSIGN
(MAKE
FULL PAGE OF LINES ON LONG SHEET)
Please mail or
pass along to any
other interested amateurs for their
signature. When full, make copies. Send original to your Division
Director, and copies to your Vice Director and Section Manager. Names
and addresses are printed on page 8 of any recent QST. -Editor
Editor, AM
Press/Exchange:
The concern regarding the AM power
reduction in the August 1989 issue
has a direct legal bearing on my 1965 Cadillac, a favorite of the five
business and family cars. When my brother, an attorney, was asked about
the lack of smog control and its great gas consumption, I was told
Congress can pass no ex-post-facto law; the Constitution forbids it.
The KW rigs from Collins, Johnson, and, likely, homebrew KW's would
seem to fall under the same protection, and FCC and members of Congress
should be told.
Secondly, Congress is worried about
the deficit in foreign trade. SSB
sees the majority of purchases come from the far East. Further this
mode has seen a demise of most of our well known American electronic
industries. FCC and Congress should be reminded of this.
Thirdly, home construction and
experimentation was a great inducement
into radio for most of us. SSB rigs are hard to repair, and the
"appliance status" likely is boring and costly for the younger
generation. Rick is correct about the magical glow of mercury vapor
rectifiers.
Finally, the summer noise on 75 has
driven many to 20. 20 is so erratic
of late that most don't know what goes on, and give up in disgust.
Would it be best for the "rock-bound" boys to use 14,286 KC and those
with VFO's to use, say, 14,280 KC. The "broad window" might have both
favorable and unfavorable results, yet quite legal and self asserting.
Chad Johnson, W5DBA
Editor, AM
Press/Exchange:
It seems to me that too many people
gather on 14.285. Most
of the time is spent waiting your turn, or listening to see if someone
is in there making a transmission. Most of us should make contact
with the people we can hear, and move off to another freq. This
will keep a lot of us from hanging on forever to get a turn.
Also, by spreading out, more people will become more aware of
A.M.
Also, we need to drag our feet after a transmission, and listen for
breakers. I hear many who break but are passed up because no one
takes the time to listen. Also, if everyone was to go off and
make an A.M. transmission with some SSB stations, more SSB people will
also become interested. I have done this in the past. These
people (most) are glad to see A.M. back again. Now these SSBers
are wanting to fire up their old A.M. gear. What better way to
get the new and old timers into A.M. Now that we are on a
roll, let's keep it going. Let's not forget about the
newcomers. So please listen up between transmissions, and spread
out on 20 meters. The more who hear us, the more who will know
about us.
73, Marty, WB2FOU/5
MODULATION MONITOR AND CARRIER SHIFT METER
JOHN
MARTIN W4KYL
I came across the following two
circuits in a couple of old magazines,
and I thought I would share them with the AM gang. I have not tried
them myself, but I see no reason for any problems.
Circuit #1
is the Sylvania Mod-Meter
of the early fifties. The input is
link coupled to the final tank and with ganged switch S1 in the RF
position, the 100uuf cap is tuned for any desired indication on the
meter. This reading will not change unless carrier shift is present,
i.e., it will not show fm-ing, drift, etc. With S1 in the AF position,
the meter indicates modulation. Calibration of percentage can be done
with a modulated RF generator and scope. S2 allows the positive or
negative peaks to be indicated.
Circuit #2
eliminates the potentially
dangerous close coupling to the
final tank. However, carrier shift indication is not included.
This circuit operates on the principle that for any modulation
percentage, there is a corresponding ratio between the carrier and
envelope amplitudes. At 100 percent modulation, both amplitudes are
equal. Calibration begins with connecting a 100 percent modulated RF
generator to the ant input. With the proper coil inserted for the
frequency in use, tune C2 for a peak reading on M1. Next, adjust C1 for
full scale deflection of M1. Finally, adjust R1 for full scale
deflection of M2. Make no further adjustments to R1. Make additional
checks at 90 percent, 80 percent, etc. At each level, readjust C1, if
necessary, for full scale deflection of M1, and note the reading of M2.
After calibration, a suitable table or graph can be drawn.
Please feel free to substitute newer
components for the CK722 and the
copper oxide rectifier.
COIL
TABLE
Coil A
1.8 - 4 mc |
57 turns No. 32 enameled wire
closewound on 1-inch-diameter plug-in
form. Tap 28th turn from ground end. |
Coil B
3.8 - 8.6 mc |
25 turns No. 26 enameled wire on
1-inch-diameter plug-in form. Space to
winding length of 1/2 inch. Tap 12th turn from ground end. |
Coil C
8 - 18 mc |
12 turns No. 22 enameled wire on
1-inch-diameter plug-in form. Space to
winding length of 1/2 inch. Tap 6th turn from ground end. |
Coil D
15 - 34 mc |
5-1/2 turns No. 22 enameled wire on
1-inch-diameter plug-in form. Space
to winding length of 1/4 inch. Tap 1-1/2 turns from ground end. |
Coil E
30 - 68 mc |
2-1/2 turns No. 22 enameled wire on
1-inch-diameter plug-in form. Space
to winding length of 1/4 inch. Tap 1-1/2 turns from ground end. |
Multi-wire Lines and Matching
Sections
By
CARL J. MADSEN, W1ZB
Radio
Engineer,
Westinghouse Electric &
Manufacturing Co.,
Chicopee Falls, Mass.
From RADIO, April, 1937
Many of our amateur antenna systems
and coupling circuits require radio
frequency transmission lines, either as impedance matching transformers
or as a connecting medium between the transmitter and the antenna
system, or
both.
During a problem of the latter type,
I found that I needed a line some
thirty odd feet long, with a surge impedance of 200 ohms. Checking all
the usual two-wire transmission line constants, I found that I needed
two 1/4 inch tubes, separated by approximately an inch. Trying to hang
a line of this type from the middle of a 66 ft. span of wire 45 feet in
the air didn't appear to be very practical, physically. A concentric
tubing line was equally impractical. Smaller size conductor could
have been used with closer spacing, but the voltages involved dictated
a design with at least one inch between conductors, especially for
outdoor operation.
After considerable investigation
through old issues of QST and RADIO,
no additional information was uncovered which might be available to
amateurs. I did find the curves shown in figure 1
in technical data
files of the W. E. & M. Co. The 200 ohm line problem then became
very
simple. A four-wire line using no. 16 wire (.060" dia.) figures out to
have a separation of 1.5 inches (.03 x 50). Using 2-1/4 inch dia.
celluloid rings (obtained in the 5 & 10c store) and drilling four
holes slightly larger than the wire, equidistant around the ring, a
light spacer of low loss is obtained, suitable for amateur application
(see page 49--RADIO, Jan., 1937 for two-wire line). These can be
threaded on the line, placing them on the wires near the ends, and then
stretching the wires tight and sliding the spacers to the desired
position. They can be cemented in place with DuPont household cement.
At least two applications, and preferably three, separated by several
hours, will hold the wires nicely.
Such a transmission line is flexible,
and must be used under slight
tension to keep the wires from twisting. Spacers should be placed
approximately every two feet. The conductors of like polarity are
connected together at the ends of the line, making it easy to connect
to the antenna system or the usual 400-600 ohm transmission line as in
the "Johnson-Q" system. The 4-wire line takes the place of the "Q
bars", making a lighter matching section.
The chart in figure
1 also gives the surge
impedance for several other
groupings that give lower impedances than the two- or four-wire
combinations. "D" is the separation of conductors, "R" is the wire
radius. The construction of these multiwire combinations becomes
increasingly difficult as the number of wires is increased; so unless
you have lots of patience and mechanical skill, it is advisable to use
the simple grouping combinations of six or less conductors.
This type of line can be used in the
Collins "Multi-band" antenna
system, or any application where a low-impedance line is required, at
considerably lower cost and with less radiation loss.
W8ZO Estate
By
Donald Chester, K4KYV
The estate of Charles A. Gault, W8ZO,
Ypsilanti, MI is now on the
market. Charlie's outstanding signal appeared regularly on 1992 khz in
recent years, until his passing a little over a year ago. His station
consisted of numerous homebrew plate-modulated transmitters, but his
signal on 160 was largely attributed to his antenna system, which
consisted of wire antennas strung between two base-insulated, self
supported 120-plus feet tall towers, which are equipped with
substantial work platforms at the top. Because of unbearable real
estate taxes, Charlie's heir has reluctantly decided to put the
property on the market, and all radio equipment, including the towers,
must go. In hopes of finding good homes for all this equipment, AM P/X
editor and publisher Don Chester, K4KYV, traveled to Ypsilanti the
weekend of the Cincinnati hamfest, checked out the equipment, and took
the photos for this article.
There are seven six-foot high
homebrew transmitters, including at least
two one-kilowatt plate modulated units. In addition, there is a
collection of transmitting tubes still in boxes, numerous components
such as transmitting capacitors, tank coils, variable condensers,
meters, modulation transformers, workshop tools and equipment, books
and magazines.
Charlie had been in radio since the
1920's, and those who know him say
he never threw anything away. The collection includes many items dating
back to the 20's and 30's; antique wireless buffs take note. Included
in the magazine collection are QST's from 1922 through the present, in
varying condition, scattered about and possibly missing some issues.
There is also what appears to be a fairly complete collection of the
pre-WWII west coast publication RADIO dating from 1936. There are also
CQ magazines from 1945. The transmitters shown in the photographs are
as follows.
Fig. 1:
(right) pair of pushpull
250TH's, modulated by another pair of
250TH's, 1KW, with plug-in coils for 20 metres, in double rack. (Left,
in the same photo): Another transmitter with 20 mtr. coils, in single
rack, with pushpull T-55's modulated by 838's.
Fig. 2:
Pair of 304TH's or TL's in
pushpull, modulated by a pair of
250TH's, with 80 mtr. plug-in coils.
Fig. 3: 160
mtr. transmitter, looks
like single 8005, modulated by a
pair of T-55's. This is apparently the rig Charlie used crystal
controlled on 1992 khz. The power rating is probably about 200 watts
input. The metal cabinet is painted with antique style black wrinkle,
with a hammered texture not seen on more recent wrinkle finishes.
Fig. 4:
Antique 160 mtr. transmitter.
203-A's in the final modulated by
a pair of 805's. Note the style of the dials. The cabinet is
metal, except for the front panel, which is entirely made of bakelite!
Most of the meters are old-style Jewells.
All transmitters are built on
casters, making them easily moveable. The
large plate modulated rigs use the RCA 1:1 5500-ohm modulation
transformers so commonly seen in post WWII homebrew AM transmitters.
Not shown in the photographs are two more six-foot racks. One is a
transmitter with power supply and a single 851 in the final. There is
no plate modulator (CW-only or grid-modulated rig?). Another similar
rack holds a low power (807 class) AM transmitter that is missing parts.
There is a 75A4 receiver in
apparently good condition, but because of
its location in a custom made console, it could not easily be inspected
internally to determine what mechanical filters were installed or its
operating condition.
Antique buffs may be particularly
interested in a genuine
motor-generator, apparently from the 1920's, which converts 120 volts
AC to 1500 volts DC at 165 mills. This is a real classic with brass
nameplates. It consists of a separate motor and generator mounted on a
steel frame with the shafts coupled together mechanically.
The owner has decided that most of
this equipment will be sold. While
he is not giving away his father's equipment, he is not insisting on
top dollar, and will accept realistic offers for any or all, preferably
from persons interested in putting it to use, not scrapping it.
AN AM ANTENNA FOR REACHING THE
OTHER
HALF OF THE WORLD EASILY
Copyrighted,
1989
by
George A. H. Bonadio, W2WLR
Watertown, NY 13601-3829
Part 8
There is a simple OTHER HALF OF THE
WORLD antenna, upon which my patent
has expired, which still baffles antenna engineers to explain it.
However, I have it all figured out. I built a new one of new parts for
$5.00. It is the supports that are expensive.
Here is the maximum possible design
(there are only three dimensions)
for extremely low angle propagation (requiring fewer hops, at less loss
per hop), with maximum broadbandedness (with a load almost like a dummy
load), of proven merit (the Army "OE254" almost copies it, and Channel
Master's "Omega" is a two element version of my three element ground
plane type, and their scanner vertical antenna on many chimneys, with
three legs into three finger spreads, borrows from it) patent expired,
a real sleeper. Revive it.
HOW IT LOOKS (drawings)
You all have heard "unreasonable"
bragging of how good "sloper antenna"
work. This system uses three slopers. You have seen how "image
antennas" diagramed underground explain the cancellation of the very
low angles of radiation. Not here.
Imagine a vertical doublet. Now split
the wires into three strands.
Spread each strand, by exactly 90 degrees away from each other
strand. Position the strands to appear to be continuous through
the feedpoint, at the center as in Fig. 1.
Look down from above it and see it as
in Fig. 2 with the visible
distance of the wire greatly exaggerated. Notice that the edge
lines of a cube at the corners are identical with this antenna wire
elements in space, 90 degrees apart from each other.
From the ground look up, lengthwise,
endwise up one element. Past
the center, the opposite is obscured endwise, also. However, the
other four elements are all seen flat broadside. They look like a
perfect X, with exactly 90 degrees spread between adjacent elements as
in Fig. 3.
If you make yours out of coated #18
wire and clear glass insulators, it
is almost invisible to a neighbor.
HOW TO SUPPORT IT
To keep the elements properly spaced,
you will need a rope or kite
string or a (clear nylon) fish line triangle across the tops, and
another across the bottoms. Use a line with over 50 pounds breaking
strength.
This pair of spacing triangles is
shown looking down onto the triangles
in which the nearer upper triangle is shown bolder in Fig. 4.
Notice the three 60 degree dotted angles. That 60 degrees is the
absolute maximum width of variation of tile support lines to keep the
sides of the triangle tight. Try to keep within half of that angular
range. The lower three element ends may either be tight, or with a
weight and an offset fishline, but also within their limits of
angle. It will still work well even if you abuse the shape
temporarily.
Thus, the antenna can be very
inexpensive, of ideal construction, but
the supports may take amateur ingenuity.
Fig. 5 shows how to dangle twin lead
from a single glass insulator in
the center and to bind the lead with many turns of plastic tape,
draping the lead loosely to the shack.
HOW IT WORKS
It splits your signal into three
equal strength amounts (because you
made all of the six elements IDENTICALLY ALIKE down to the number of
turns on the soldered loops on the insulators). These three
signals are substantially equal and are 90 degrees apart. Thus, the
fields from each wire are independent from the other two doublets, each
90 degrees apart from each other. (Computer programs on antennas do NOT
factor this in -- sorry!)
Now, it is well established that both
vertical and horizontal antennas
emit fields that reflect off the ground with a 180 degree
reversal. This reversal practically neutralizes the distant
signals under 5 degrees, and it still causes great loss even at 20
degrees.
The result of these cancellations of the strongest and lowest lobes is
a lesser strongest lobe near 25 degrees.
Apparently there is no way for the
earth to effectively reflect your 3D
signal in a reversed polarity to neutralize your very low angle
radiation. Thus, the Bonadio Space Dimension, or 3D, Antenna cannot be
improved upon as it is the limits, by evolution of three other patented
antennas, to the whole extremes of 3D at 90 degrees apart from 90
degrees apart from 90 degrees. There are no more worlds to
conquer. This does it.
In Fig. 6, you can see that a two hop
reflection at -10dB per reflection can
cost -30dB, but one low angle hop has less loss, say -6dB, and it
dominates when half way around the world or farther. You will
hear, "You're the only American whom I can hear on the band."
ELECTRICAL
CHARACTERISTICS
The Bonadio Space Dimension -- or
let's call it the "Bonadio 3D", has
almost no reactance to trouble us with at any frequencies higher than
its first (longest wavelength) resonance. Its reactance value probably
does not exceed a very low +/-10 ohms. The mismatch of the feeders will
generate more reactance than the antenna itself,
unlike slim wire antennas.
Do not try to feed this antenna
through a balun, because neither the
balun nor the antenna will hold back your harmonics. See a previous
story in this series for a tuner design that will tune easily, have no
power factor problem, and that filters down harmonics very well.
The load will approximate 200 ohms
from its longest first resonance to
all shorter wavelengths. Use twin lead, preferably kilowatt
transmitting twinlead (see Belden catalogue) because it is more
permanent. However, Radio Shack has usable outdoor twinlead in a
brown color.
Notice that you can tune the antenna
into your receiver and peak it
before using your transmitter at "tune" so that it loads easily.
Avoid tuners with differential capacitors such as the old Matchboxes,
or where your feeders tap into mid-turn of coils as in
Transmatches. They can, half of the time, show you SWR's of 1:1
and still not deliver half of your power in or out as explained in an
earlier story in this AM Press/Exchange series.
WHAT TO EXPECT
Excitement! You will
immediately hear DX better than you have
heard it before -- and they will be hearing you, where they never heard
you before.
Expect to not get reports of fading
as much as you are used to getting.
Expect to have to ASK as to how
signal your signal now compares with
other American signals that he has just been hearing, or really his
report is meaningless.
Expect to have to explain to your
neighbors that this thing is really
"an electric day and night passing bird counter, just disguised as an
antenna".
Expect that you will have to assign
some of the rest of your family to
take care of all those great QSL'S.
Expect that you will need QSL's to
satisfy nearby hams who hear you,
but do not hear your DX. (Yes, you will have extended ground wave
also.)
BONADIO SPACE DIMENSION
ANTENNA |
Optimum Dimensions |
Lowest
band of
operation
|
Each
Arm |
Triangle
Side
|
Vertical
Space
|
Support
W/8’
|
2
mtrs |
2’ 5” |
3’ 4” |
2’ 9” |
11’ |
6
mtrs |
7' 2" |
10' 2” |
8' 2" |
16' |
10
mtrs |
12’ |
17’ |
13’ 7” |
22’ |
15
mtrs |
18' |
25' 5" |
20' 5" |
29' |
20
mtrs |
24’ |
34’ |
27’ 3” |
35’ |
40
mtrs |
48’ |
68’ |
55’ |
63’ |
75 mtrs
|
90’ |
127’ |
102’ |
110’ |
160 mtrs
|
192’ |
272’ |
218’ |
226’ |
EXCHANGE
(Contact
information removed; ads are
from 1989.)
FOR SALE: Tubes new boxed 805 $20
each. 813 $20 each. 814 $10 each.
Octals & locktals $2 each. Dow coax relays 115v $20 each. 1 KW 115v
isolation transformer $50. Variacs 115v 15 amp powerstats $50. Plate
transformers, high current filter chokes 400 ma $35 each. Components
for linears inquire. Levy (the tube man).
WANTED: Manuals for the Heathkit
pair. MR-1. MT-1. Will pay for
shipping and copying. Marty Drift.
FOR SALE: RME DB22A preselector. 540
kc - 42 mc in 4 bands. Version
with grey wrinkle case and chrome tuning knob, 2 6BA6 tuned RF stages,
and built-in power supply. Good physical condition and works (recently
checked out), but some scratched spots on paint. No manual. $30 plus
shipping. WANTED U.T.C. LS-18, LS-49 audio transformers. Also Chicago
BD-2. K4KYV.
WANTED: Good used or new type 304TL
tube. Advise price and condition.
Bill, KD0HG.
FOR SALE: Heathkit TX-1 Apache
transmitter. Heathkit RX-1 Mohawk
Receiver and SB-10 Sideband adaptor. Sell as set only. $300. Call,
leave phone no. if I am not home.
WANTED: Info or schematic for Elenco
"Power Gainer" audio compression
amp, circa 1959. John Morehead, N9HRS.
WANTED. Patterson PR-15 receiver;
clean but need not work. Any
wavemeters, any age or condition. Rick Ferranti, WA6NCX
WANTED: Driver transformer single
plate to pushpull grids (807's) for
Viking II transmitter. Also wanted NC-300 in excellent condition.
Howie Jack, W2NRM.
WANTED: Steel relay rack meter panel
5-1/2" high for (5) 3" meters.
James Schliestett, W4IMQ.
FOR SALE: Johnson Thunderbolt $450.
6N2 $75 (with VFO). Ranger II $150.
WANTED: 4-1000A socket, bakelite panel meters, Johnson Valiant, 830B
tubes, TV-2 tube checker. Parker, W1TG.
Doctor Marty's Heathkit Service
Looking for that old Heathkit you
missed building years ago? Need a
manual? Want to trade, sell, buy, parting an old rig out? Need parts?
Place your needs with us and maybe we can be of help. All needs will be
placed on master list. In order to get master list just send large SASE
to: Marty Drift.
Keep Those Articles Coming!
If you have submitted an article in
the last few months, please do not
assume it was rejected for publication because it has not yet appeared.
Articles are not necessarily published in the same chronological order
in which we receive them. Lately, because of the urgent AM power issue,
space has been limited for our normal articles, and there is presently
a backlog of good articles waiting for space available. We still need a
steady supply of new articles or the supply will soon become depleted.
This is the AM
PRESS:
An amateur radio publication
dedicated to Amplitude Modulation.
This is the
AM EXCHANGE:
Offering FREE ADVERTISING to enhance
the availability of AM equipment
and parts.
Edited and published by Donald
Chester, K4KYV
NOTICE: The purpose of this
publication is the advancement of Amplitude
Modulation in the Amateur Radio Service, and there is no pecuniary
interest. Therefore, permission is hereby expressed for the use of
material contained herein without permission of the publisher, with the
exception of specifically copyrighted articles, provided that The AM
Press/Exchange is properly credited.