[IW5EDI] Getting started on FT8

[IW5EDI via rec.radio.amateur.moderated Admin]

IW5EDI Simone - Ham-Radio

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Getting started on FT8

Posted: 04 Sep 2017 02:11 PM PDT
http://www.iw5edi.com/ham-radio/2283/getting-started-ft8


Last night Ive finally found the time to start experimenting the new FT8
digital mode, directy from my iMac.
FT8 QSOs

Its still too early to give a feedback, but Ive been really impressed by
the automatic (auto sequence) mode, that allows automatic QSOs starting
from the Calling CQ till the final 73!.

Well, honestly Ive found it very easy to setup, but also too much
automatic, allowing my iMac to conduct several QSOs in behalf of me without
requiring my interaction. Absolutely inpersonal and totally asectic.

At the very first, Ive downloaded the current stable WSJT-X version 1.7,
but Ive suddenly realized that FT8 was not implemented in that version, and
therefore Ive decided to download the 1.8 rc2.

Configuration, required some changes on OSX settings, and a reboot, while
the connection to my TS-590S required some tricks. I copied the settings
from the RUMlog configuration, and it worked immediately.
TS-590S MacOSX



The post Getting started on FT8 appeared first on IW5EDI Simone - Ham-Radio.


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Comet CHA250B Review

Posted: 10 Jul 2017 02:22 PM PDT
http://www.iw5edi.com/ham-radio/2275/comet-cha250b-review






While evaluating HF multiband vertical antenna I found this interesting
review about the CHA250B by Comet.

I saved for further reference, author is K3DAV whose site is gone qrt.
Comet CHA250B HF Vertical 
By David K3DAV  (2/7/2012)

There are a few compromise HF vertical antennas within the same class as
the Comet CHA250B on the market.   
     BUTTERNUT makes the HF6VX, but you need to buy extra kits to add some
of the bands. That

doesnt make much sense.
     DIAMOND has one similar to the Comet called the BB7V. It has a cheap
design with a separate

add-on load coil with a flimsy wire that connects the coil to the main
element. That doesnt

make much sense either.
     GAP ANTENNA makes the TITAN-DX. But in reality, it is a center fed
vertical dipole. Only the

top half is a main radiator. And this thing has way too many ugly radials
sticking out in all

directions that can break off in the wind.  This thing is an eye-sore.
     HUSTLER has the 6-BTV. Not a bad antenna, but it is loaded with
several power robbing

band traps.  Again this makes no sense.
     HY-GAIN has the AV-18AVQII, but again with all of those power
thieving traps for certain

bands, and a separate add-on load coil for 80 meters. Whats up with that?
     JETSTREAM makes a real look-a-like, copycat version of the CHA250B
called the JTV680. But

the JTV680 is made of thinner lower grade aluminum that will break easier
in the wind, and

the coil is basically a fat 50 ohm resistor type that sucks power away.

And every one of those antennas have high SWR throughout the HF band that
requires you to have or purchase an antenna tuner.  That means they all
have a poor impeadence match which robs even MORE of your power. (Except
the JTV680 which just uses a big fat resistor to rob your power.)
Then there is my favorite.
The little antenna that could.

Just to reassure you, I do not work for NCG Company, (the parent company of
Comet antennas), and they do not pay me for this review. I am just so
impressed by the performance of the CHA250B, that I thought it was worth a
page on my website. So take every word I say here as pure and quite honest.
And I never exaggerate.
The Comet CHA250B HF Vertical.

I fondly call it my 24 foot dummy load.  The design of this antenna is so
simple it is almost stupid. At first glance, it is pleasing to the eye.
Nice shiney aluminum standing tall, and thats it. No big ugly
radials anywhere from head to toe. More importantly, there are NO FREQUENCY
TRAP COILS to suck away your power.  The entire length is one continuous
piece of aluminum tubing, and the whole element radiates RF at all
times.  Actually, it kinda looks like an old style CB antenna. My first
thought was, how can this thing work? Its just a balun with aluminum tubing
far too short for frequencies below 15 meters. But after my experiences
using this antenna, I can tell you, IT WORKS pretty damn good. At
least much better than I ever expected it would.

A diagram of the matching transformer built-into the big round black
housing within the mounting bracket.





Before you decide to purchase one, keep in mind that this antenna is a
compromise antenna. It will not give you top performance like a monster
yagi or a perfectly cut dipole up high. But if you are space restricted
like me, and want a good HF vertical to get you talking on HF, this is the
one antenna to own. As I have told many hams who laugh at this antenna, You
may not give the guy in Australia a big 20 or 30dB signal, but I gave them
an S-9 signal, and we had a very nice QSO. And isnt that the whole point of
ham radio? Making the contact, and possibly a new friend? Also keep in mind
that you can NEVER use a linear on this antenna. It can handle a maximum of
250 watts SSB, but only 125 watts on AM & FM. This antenna is for the space
restricted ham who only uses the 100 watts of power out the back of the
radio.

These are quotes from the NCG website about their own product.

If you have the space, budget and desire to erect a full size antenna
system we suggest you do so bigger IS better. Howeverif you live in an
antenna restricted area and must manage with antenna or space restrictions,
or you simply wish to operate incognito,  you will be forced to make
significant antenna compromises.  The CHA-250B will make the most of these
circumstances!
The Comet CHA-250B is a newly design broadband vertical with NO GROUND
RADIALS. This antenna is EXTREMELY easy to assemble, requires no tuning or
adjustments and VSWR is under 1.6:1 from 3.5MHz 57MHz!


And for you guys who already have yagis or dipoles on huge towers, the
CHA250B is a good standby, or can be used as just a good omnidirectional
monitoring antenna to see whats on the bands. This antenna is quiet with
great ears. And it covers the entire HF spectrum, so it makes a fantastic
general coverage antenna. It also covers TX on the MARS/CAP frequencies.

The CHA250B comes in 5 pieces. Assembly took me 20 minutes. The entire
antenna is 6068 aircraft aluminum, and fits together easily.  Each section
going up fits inside the one below it. Two of the sections are pre measured
with pre tapped holes for inserting a small sheet metal screw. The other
two sections must be measured to set them correctly. They too slide inside
the lower section, but are held in place with a hose clamp. You only need
to measure the element a few inches from the bottom end that slides into
the other section. The instructions give you the exact measurements to use.
Mark the measurement with a marker or a scratch, then insert the element
exactly to the mark, then tighten the clamp. Then you are ready to raise
the antenna into its new home. From opening the box to complete
installation took about an hour.

The specifications for the CHA250B are very simple. Here is how the NCG
website list them.

Broadband: TX 3.5 57MHz RX 2.0 90MHz

VSWR: 1.6:1 or less

Max Power: 250W SSB, 125W AM-FM

Impedance: 50 Ohm

Length: 235

Weight: 7 lbs 1 oz

Connector: SO-239

Mast Size Required: 1-2 diameter

Max Wind Speed: 67MPH

The following is the measured wavelengths on particular bands for the
CHA250B. No tuner is needed except for 160M as this antenna is not designed
for use on 160 meters.



At 1.900MHz this antenna equals a 0.045 wave. (Ant. Tuner Required)

At 3.600MHz = 0.084 wave.

At 60 meters = 0.120 1/8) wave.

At 7.100MHz = 0.166 wave.

At 10.130MHz = 0.236 (1/4) wave.

At 14.200MHz = 0.331 (1/3) wave.

At 18.170MHz = 0.424 wave.

At 21.200MHz = 0.495 (1/2) wave.

At 24.950MHz = 0.582 (5/8) wave.

At 28.500MHz = 0.665 (2/3) wave.

And finally at 50.000MHz = 1.165 wave. Too long for 6M, but still works.


NO TUNER REQUIRED FOR HF. NO KIDDING!

The entire antenna is just over 24 feet tall including the base load coil
and mounting bracket. The coil is built into the bracket, and is the most
important part of the antenna. The coil is built like a transformer, and
provides a nice 50 ohm load on all bands. NO JOKING! I put my MFJ-269
analyzer on this antenna including the 60 feet of coax into the shack. I
can spin the tune dial on the analyzer from 3.5MHz continuously scanning
the entire HF spectrum through 54 MHz, and the SWR never goes above a 1.6.
It is usually near flat except for a few band edges. When I checked below
3.5MHz or above 54MHz, the SWR starts to climb fast. But between those two
frequencies, it is great. Even on 60 meters. I am not exaggerating. It
really is that good. You do not need a tuner with this antenna on any HF
band. As I said, the load coil is a transformer, but it acts sort of like a
dummy load. They take a tap from the coil through capacitance to feed the
main element.

There is only one exception, and that is on 160 meters. The CHA250B is not
designed to cover 160M, so a tuner is necessary. See down below for more
details about this antenna and 160 meters.
No counterpoise or radials required. REALLY!
But they can help.

Because of the load coil design which uses the coax or metal mounting pole
as a counterpoise, you do not need ground radials or counterpoise wires
with the CHA250B. It works quite well without them. I can tell you this
from my experience. My first contact on this antenna was a ham in Scotland
on 20 meters. I only use the 100 watts from my Icom 746PRO. We talked for
about 15 minutes and he gave me a signal report of S-9 to 10dB. I had about
the same on him. He never seemed to have any problems hearing what I said,
as he always responded to the points or questions I made. I knew at that
point that this antenna was pretty good. By the way, I only use LMR-400
coax with all of my antennas including the CHA250B.

I used to talk with a few guys in a free-for-all QSO just before sundown
every night on 75 meters. 3805kc to be exact. I am in central PA near
Harrisburg. The others were all around PA with one guy in upstate NY. He
would get an S-5 or S-6 from my little antenna over 120 miles away. But
after the sun went down, I talked up and down the eastern seaboard. A
friend close by to me suggested I install a couple of counterpoise wires.
So we cut 2 wires, one at a 1/4 wave on 75 meters, and the other to a 1/4
wave on 40 meters. My friend in upstate NY said my signal went up to an
S-9, bordering on 10dB. So it made an improvement. This is something to
note about the CHA250B. It can run without the counterpoise wires, but it
helps to add them.
BUT! Theres A Bonus Feature I didnt Count On.
160 METERS.

The CHA250B antenna is not designed to work below 80 meters. At least
according to the manufacturer. But just out of curiosity, I tried it on 160
meters. Keep in mind that my CHA250B is only 20 feet from its mounting
bracket to the ground, and I use LMR-400 coax. So as they say, your milage
may vary. The SWR on 160M is right on a 3.0. I hit the button for the
auto-tuner in my 746PRO, and in 5 seconds it tuned it to flat. So far on
160 meters, I have worked NY, NJ, IA,OH, IN, VA, and NC. Not too shaby for
a 23.8 foot dummy load. I know it is nothing compared to a good 160M
dipole, but it works and I made contacts.

As for performance the CHA250B actually covers the frequencies as
advertised, but it has its limits. I have found the CHA250B to work very
well on 75/80, 60, 40, and 20 meters. I have now worked all continents
(Except Antartica) on those bands with it. Usually with good reports. I
have even broken through pile-ups with just 100 watts. But as you go above
in frequency, the performance slightly drops off, but not so bad that you
cant still make good DX contacts. I find 17 and 15 meters to be pretty
good. 12 and 10 meters is fair to OK, but it could be better. But even
though the manufacturer says it works on 6 meters, it is fair to poor on 6
meter performance. It is over a full wave on 6M, so I didnt expect too much
up there. My old GP-15 was 200% better on 6 meters. But it does work there.
So I have come to certain conclusions on my antennas. The CHA250B works
very well for me on 160 through 20 meters. So they are the bands I use this
antenna for. I have a Solarcon I-MAX 2000 for 17 through 10 meters. The
I-MAX 2000 is the best vertical antenna for these bands. It performs better
on 17 and 15 meters, but a whole lot better on 12 and 10 meters than the
CHA250B. And I already have a Comet GP-9 for 2M/440, and a Dominator 6M for
6 meters.

I know of several hams that have purchased the other brand name verticals I
mentioned at the beginning of this article, and they were not all that
happy. I talked them into trying the CHA250B, and they were very surprised
at how well it works for what it is. They all agreed it was an improvement
over their original HF vertical purchases. All of us so far believe that it
works at least better than we thought it would for a compromise antenna
with such a simple design.If you have any questions about the CHA250B
contact me at ke...@msn.com





The post Comet CHA250B Review appeared first on IW5EDI Simone - Ham-Radio.


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Vertical antenna for ham radio 40 meter band

Posted: 01 Jul 2017 12:42 AM PDT
http://www.iw5edi.com/ham-radio/2259/vertical-antenna-ham-radio-40-meter-band


PY1BEK Vertical antenna for ham radio 40-meter ham band (7 MHz)

This self-supported vertical antenna was made with aluminum tubes of 3 m in
length that have an external diameter of 32 mm and a wall thickness of 1.2
mm. The total length of the radiating system is 10.33 m and its
square-shaped base measures 25 cm on a side.

To the theoretical length (1/4 lambda) was added 4% due to the width of the
antenna.

The various lateral stabilizing and connecting rods of the tower are made
from rectangular shaped aluminum bar (17.0 mm x 6.5 mm) and are secured to
the tubes with pop-rivets that are 1/2x 3/16 in diameter.

Those rivets are much better than bolts and nuts completely free of
galvanic corrosion (same metal) and the pressure achieved with an hand tool
will be more than sufficient to make a solid mechanical and electrical
connection good for many years.

Here is a summarized list of materials: a total of nine (9) 3.0 m aluminum
tubes have been used, one (1) 50mm diameter PVC tube, 2.5 m in length, 12
meters of aluminum bar (the stabilizing rods), 140 aluminum pop-rivets, and
9 inox steel braces of 45 mm in diameter.

The total weight of the radiating system is less than 15 kg, perfectly
supporting winds of 90 Km/h as a lower limit in a computerized simulation
and without the necessity of stays.

Since the revision date of this article, the antenna is already more than 3
years old and its efficiency is the same as when it was mounted.

The unions between the aluminum tubes was made with small pieces of copper
pipe 20 cm in length and whose external diameters fit perfectly in the
interiors of the aluminum tubes.

Small longitudinal “ridge” cuts (10 mm) on the tips of the aluminum tubes
have allowed them to be firmly pressed, with the inox steel braces, onto
the copper pipes and make good electric and mechanical contact.

The four insulators of the base of the antenna are made with Brazilian
TIGRE PVC reducer unions.

Four (4) sections of weldable PVC (brown core), 50 mm in diameter have been
used, with 60 cm of length embedded in the center of the concrete base and
on the exterior tips (80 mm) two reducer unions have been joined with TIGRE
PVC glue.

In the center are positioned 32/40 mm reducers that are then coupled via
40/50mm reducers to the 50 mm diameter PVC.

Glue is also applied on the tip of the pipe displayed above of the concrete
mass.

In these insulators the four feet of the antenna are placed.

They are introduced 30 mm inside of the lesser sleeve, until theyre jammed
inside.

Completing the setting, four screws of 3/16 x 2 cross the interior of each
insulator, thus securing the antenna to the support.

The tower properly set has an upper part formed by a 6 m mast with a single
tube sliding portion of 5m by which Standing Wave Ratio (SWR) adjustments
can be made. After the adjustment, single inox steel brace will keep the
upper mast in position.

The support insulator was buried to the soil with concrete (cement, rock
dust, and 20mm stone aggregate at ratio of 1:4:4) in a squared hole of 40
cm width and 80 cm deep. In the deep end of the hole four linked 2.4 m
copperweld poles had been inserted and interconnected with 25 mm2 flexible
cable so they will be part of the grounding.

Measurements made with a milli-ohmmeter resulted in a 3.6 ohm when all the
poles were in place.

Beyond the copperweld poles, a system of 13 radial of 10 m length, using
sections of flexible copper wire (1.5 mm in 2 sections) were attached to
the ground terminal.

These wires are embedded and hidden to a depth of 10 cm underground and
complete the grounding.

The fact that, as embedded, the radials lose their resonance means that
their exact length is not very significant.

However, their combined effect on impedance is not negligible. In practice,
the ground impedance obtained was around 20 ohms.

This was then added to the theoretical impedance (35 ohms) of the 1/4 wave
antenna which then became close to the 50 ohms necessary for correct
adaptation to the coax cable RG-213. With the low Q of the antenna, the SWR
over the whole band was well below 1.2:1.

In the top, an element was placed as a driver for the 50 MHz band,
transforming the upper part of the antenna to a 1/2 wave radiator for 6
meters (3 DB of gain over isotropic). The J-Pole was made with copper pipe
of 15 mm diameter and whose length was 1.47 m. It has an independent coax
cable of RG-213 that goes down into the interior of one of the tubes of the
antenna. This element for 50 MHz does not interfere with the main antenna
that continues to resonate at 7 MHz. The SWR at 50.500 MHz is 1.0:1 and
reaches 1.2:1 between 50.000 and 51.000 MHz.

My next experiment will be in making a radiating system with a J-Pole for
10 meters whose photos will be published upon its successful completion.

More information on vertical antennas can be found at this excellent site
of L. B. Cebik, W4RNL.

Also, I would sincerely thanks the impressive cooperation of Ken Beck, WI7B
helping us with this English translation.

73, Sergio Valente, PY1BEK

http://svcglobal.com/antena/index.html

















The post Vertical antenna for ham radio 40 meter band appeared first on
IW5EDI Simone - Ham-Radio.


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50 MHz 4 and 7 elements Yagi Drawings

Posted: 03 Jun 2017 01:34 AM PDT
http://www.iw5edi.com/ham-radio/2253/50-mhz-4-7-elements-yagi-drawings


Just found this two old antenna drawings for a four and a seven elements
yagi antenna by WB7PMP.



Looks interesting plans but have not yet attempted to build them.

The post 50 MHz 4 and 7 elements Yagi Drawings appeared first on IW5EDI
Simone - Ham-Radio.


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The 9:1 Balun

Posted: 11 May 2017 12:49 PM PDT
http://www.iw5edi.com/ham-radio/2248/the-91-balun


During my recent holidays in Sardinia Ive been experimenting some portable
wire antennas.

Since some years to now, I use to bring with me just a 10m fishing pole and
some wires. This year Ive decided to take with me some thoroids, copper
cable, and a solder and homebrew a balun.

One of the balun Ive used is the 9:1 balun, an impedance transformer to
feed a high impedance, end fed random wire antenna connected to my fishing
pole.

These are some schematics Ive used as reference


9:1 antenna-balun













Ive used a T-200 thoroid for my 9:1 Balun, thin copper cable, and a PL coax
connector.



The post The 9:1 Balun appeared first on IW5EDI Simone - Ham-Radio.


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Double Bazooka Antenna

Posted: 29 Dec 2016 08:52 AM PST
http://www.iw5edi.com/ham-radio/2240/double-bazooka-antenna


The Double Bazooka Antenna is simple to build broadband dipole antenna





Someone consider the double bazooka antenna to offer a 3dB improvement over
a common dipole antenna. The only caveat is that an antenna tuner must be
used.

The design is easy to replicate and uses common materials. It is mostly
made of RG58U coax, #16 automotive wire, rope suspension, and any plastic
that can be cut into insulators.

This antenna can been used on 80 through 10 meters by cutting it to the
center frequency.



The post Double Bazooka Antenna appeared first on IW5EDI Simone - Ham-Radio.


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QST - Digital edition, not for me sorry.

Posted: 18 Dec 2016 02:49 PM PST
http://www.iw5edi.com/ham-radio/2229/qst-digital-edition-not-sorry

QST in my Android

As ARRL member, I love to read QST from time to time.

Honestly its the only real advantage of the membership. Being Italian, I
cant really benefit of all club services, and QST is the real added value.

I consider myself  a casual reader of QST, since spare time is always very
short and time to read magazines is a rarity. But, I love to take QST
during my travels abroad. Reading QST in the airplane has become a nice
habit.

The last year I wanted to test the Digital Edition only, just to save some
bucks.

Unfortunately I did not bring with me the tablet, since I always have with
me my own iPhone and the Business Android smart phone, and a third device
is really too much.

Well, this week during a travel to France, I decided to download latest
issues.

The experience has been very poor, Im not been able to read a single
article, since Ive found many difficulties on zooming and moving the page
to follow the 3 columns format of QST Articles.

Tapping, swiping, pinching open etc has become really a pain, after some
minutes I was trying to zoom and move page, to follow the article flow,
irritated, I gave up.

Result ?

Ive just renewed my yearly ARRL membership asking for the paper QST edition.

I would recommend ARRL to create a Digital edition, with a format suitable
for the small mobile devices, and not a simple transposition of the paper
format. I do understand its much cheaper, but at leat for me, it is a real
pain.



The post QST Digital edition, not for me sorry. appeared first on IW5EDI
Simone - Ham-Radio.


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Double Windom Antenna

Posted: 15 Dec 2016 03:07 PM PST
http://www.iw5edi.com/ham-radio/2221/double-windom-antenna

A Double Windom Antenna for Eight or Nine Bands

By Hubert Scholle, DJ7SH, and Rolf Steins, DL1BBC

The asymmetrical dipole antenna developed and described by Windom (W8GZ) in
1929 has been used by many amateurs for many years as the FD4. This has
also been the case in Germany.

We discovered in an older periodical (QRV) the explanation by F. Spillner
(DJ2KY) that this antenna, with the addition of a small one-band Windom for
15 m, can be used as a five-band Windom. After the installation of the
additional elements, this antenna worked very well for two years at DL1BBC.

With the opening of new bands (10, 18 and 24 MHz), the thought occurred to
try out a new extension of the FD4 to eight bands (3.5 to 29.7 MHz).

What worked for 21 MHz must also be possible for 10 MHz.

So we took off the 21-MHz extension to my antenna and hung two elements of
4.69 and 9.38 in (15.39 and 30.77 ft), respectively, on the FD4 and
stretched these downwards from insulators as an inverted V (Fig A).



To calculate the length we used the formula:

L/2 = 142.5 ÷ f (Eq A)

Whatever would work for 30 m should also work on 15 m.

As suspected, it worked.

As a by-product, it turned out in the measurements that this double Windom
resonated just as well on 18 MHz and 24 MHz. So our eight-band Windom came
into being with really simple means.


Construction

Thanks to our neighbors, we were able to extend the basic antenna (FD4) to
its full length.

At DL1BBC it was installed about 6.9 m (22.63 ft) above the ground, rising
to about 8 m (26.25 ft) at each support point. At DJ7SH it hung about 5 m
(16.4 ft) above the ground and partly ran over a garage roof. Both
extension legs were stretched downwards as an inverted V with an angle of
about 100°. Changing this angle allows the whole antenna to be easily tuned
during final adjustments.

After construction, the first measurements showed that because of the
length of the 30-m elements, the 80, 40 and 20-m bands each had a resonance
point that was shifted towards the low end of the band. This effect was
eliminated by lengthening slightly the 30-m section, so the resonance
points fell more in the middle of the bands.

With this adjustment, the resonance point on 30m shifted slightly towards
the end of the band, but this can be tolerated.

With all measurements of the Windom, it was very clear that how the feed
line ran played a decisive role.

According to our results, it must be stressed that the feed line must run
first vertically downwards from the feed point to the ground and only then
to the shack, as otherwise the entire antenna may be detuned. This is
especially the case when the height of the antenna is under 10 m (32.8 ft).
The 50-ohm-coax feed at DL1BBC was pulled through an old garden hose and
then buried under the lawn.

The lower antenna height at DJ7SH had the result that, with the first
construction attempt, the precalculated length of the 30-m elements was
exactly right. The antenna delivered on all eight bands at the first go.

As can be seen from the SWR charts (Fig B), at DL1BBC the match on 40 m
turned out somewhat less favorable. However, this was immediately fixed by
changing the antenna height slightly. At DJ7SH, no resonance curve ran
above 1.5:1, which was the goal since neither station uses an antenna tuner.
Fig B SWR curves for the eight-band double Windom [These curves do not
cover all US amateur frequencies because allocations in the FRG differ from
those In the US Ed.]
Performance

First contacts were made with both antennas. These showed that the antennas
had a good degree of performance for a long wire. Especially the downwards
sloping extension elements have a clear advantage over the horizontal basic
antenna for DX.

With the first try on 30 m, many contacts were made with the US (East and
West coasts), with signal reports between S6 and S7 while running 100W.

At present, we cannot make a concrete statement about contacts within
Europe.

This article makes no scientific claims, but intends to stimulate the
long-wire enthusiast, and especially the friends of CW.
Part 2: Adding Another Band

Because the response was unexpectedly great to the publication of the above
in cq-DL, we went to work again on an extension, as it was worthwhile to
add 160 m.

With a half wavelength at 1.835 MHz, we calculated the basic length of the
antenna to be 77.65 m (254.75 ft). We tapped the antenna at 25.88 m (84.9
ft) from one end and fed it with 50-ohm coax through a 6:1 balun. The basic
antenna of this length was installed horizontally as a reclining L at
DL1BBC. The additional elements, with lengths of 4.69 and 9.38 m (15.39 and
30.77 ft), were attached at the balun. This additional Windom for 10 and 21
MHz was again stretched downwards as an inverted V with an angle of about
100°. Here the additional Windom was mounted so that its elements were not
extended in the same direction as those of the reclining L, which gave
sufficient decoupling (Figs C and D).

Fig D Top view of the nine-band double Windom. [The elements are
positioned to reduce coupling between the antennas two ott-center-fed
dipoles. Ed.]

For the feed, the Fritzel company made available for testing a new 6:1
balun, series 83, which can also handle high power. The SWR charts (Fig E)
were obtained with the wire lengths given in the preceding paragraph. In
case builders experience slight resonance shifts, these can be balanced out
by lengthening or shortening the additional Windom.


Fig E SWR curves for the nine-band double Windom.


Performance

First contacts were made with the antenna installed at DL1BBC. Here it was
once again shown that the antenna has a good degree of performance for a
long wire, especially for 1.8 and 3.6 MHz within Europe. The additional
Windom again had the degree of performance described in the first part of
this article.

The authors welcome questions and exchange of information. (When writing,
please include return postage.)

VE2CV, John Belrose and VE3KLO, Peter Boubane.

The post Double Windom Antenna appeared first on IW5EDI Simone - Ham-Radio.


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IW5EDI new facebook profile

Posted: 06 Nov 2016 02:23 PM PST
http://www.iw5edi.com/ham-radio/2216/iw5edi-new-facebook-profile


Since more and more hams are joining the Facebook social network, Ive
recently decided to create a separate personal profile for ham radio posts.

The reason why I decided this is because, sometime is useful to create
public posts, that can be re-shared.

Within my main profile, I have several friend lists with different audience
profiles,  where I publish posts. Unfortunately posts published to these
lists cant be re-shared public.

So if you wish to connect my ham radio Facebook profile contact me on
Facebook



The post IW5EDI new facebook profile appeared first on IW5EDI Simone -
Ham-Radio.


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59th Jota - operating II5BP at Firenze 8

Posted: 20 Oct 2016 12:58 PM PDT
http://www.iw5edi.com/ham-radio/2202/59th-jota-operating-ii5bp-firenze-8


Last week-end Ive spent few hours with the Agesci Firenze 8 Scout Group for
the annual Jamboree On the Air.

Here some pictures Ive taken



The post 59th Jota operating II5BP at Firenze 8 appeared first on IW5EDI
Simone - Ham-Radio.