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Re: [HCDX] Dxers Unlimited's date error... please read below
Sorry amigos...
The date of the script is 5-6 December !!! as ammended below
Dxers Unlimited
Dxers Unlimited's mid week edition for December 5-6 2006
By Arnie Coro
radio amateur CO2KK
Hi amigos radioaficionados, with our now traditional salute, half in
English, half in Spanish, I am opening up the mid week edition of Dxers
Unlimited, your favorite radio hobby program. My name is Arnaldo, but
everyone in the radio world knows me as Arnie, and as always it's my
pleasure to share with you about seventeen minutes of on the air and on
the world wide web time... Here is item one: Fresh direct and from the
source, BIG SOLAR FLARE.... an unexpected X9
type flare, yes , you heard it right, and the active region that
generated this really big solar eruption is still at the Sun's limb, so
it will have to transit right trough the solar disk for about two weeks,
before it turns around , and in the meantime we may be seeing some very
interesting fireworks from the Sun... As of now the expected solar flux
may cross the critical 100 units mark maybe by tomorrow...do remember
that the the July 2006 monthly solar report that my good friend Angel
Gonzalez Coroas, Cuba's most experienced solar optical observer sent me
showed that the WOLF number for the month of July was 16, and that the
highest number of sunspots registered on a single day during the whole
month was 36... Other details about this very elaborate solar report
show what in my opinion is the most relevant data... NO sunspots from
cycle 24 have yet been seen , despite the fact that Angel is doubling
the number of his daily comprehensive solar optical observations, aiming
at trying to find the higher solar disk latitude sunspot group that will
signal the start up of cycle 24. So, if we follow the Cuban expert's
point of view
the two small reverse magnetic configuration sunspots observed
previously may be attributed to chance rather than to the actual
beginning of cycle 24.
In comments sent together with his report, the Cuban scientist explains
that he is now changing his estimate for the beginning of cycle 24
further away , probably by the end or next year... If this becomes a
reality, then poor HF propagation conditions on the higher frequencies
are going to last longer than expected.
But, I must now ask him about this new big sunspot that is already
producing X level type solar flares...
Item two: Monitoring civil aviation traffic on the VHF short range band
between 118 and 136 megaHertz is not only very interesting, but also
sometimes provides with highly stressful moments, especially when bad
weather makes aircraft operations much more difficult. Among the popular
radio receivers that do have the capability of AIR BAND monitoring is
the now classic SONY ICF2010, but you can also monitor the 110 to 136
megaHertz segment of the VHF spectrum with a home brew solid state
converter connected ahead of your standard AM short wave broadcast
receiver... All I can tell you is that it's pretty fascinating listening
amigos !!!
Stay tuned for more radio hobby related information , and don't forget
to look around for paper , pencil or pen , ready to write my e-mail and
also my postal address ...
I am Arnie Coro in Havana, back with you in a few seconds
.....
Your radio is tuned to Radio Havana Cuba, on one of our short wave
broadcast bands frequencies. At present we are using 6060 kiloHertz on
the 49 meters international broadcast band in English from 0500 to 0700
hours UTC... beaming to Eastern North America, but also reaching at
times, when propagation is good up to the United Kingdom, Scandinavia
and Germany. We are also using 11760 kiloHertz in English from 0500 to
0700 UTC with an omnidirectional 6 dB gain antenna, and are receiving
now some nice reports from Australia and New Zealand....and the new 6180
kiloHertz with our 340 degrees azimuth curtain array is beaming to
Central North America, from 01 to 07 hours UTC too. Now here is item
four of the mid week edition of Dxers Unlimited amigos... Lack of
amateur radio activity on open bands, providing at a specific moment
excellent propagation, is worrying hams all over the world, because this
may lead to actually using some segments of the amateur bands to other
users of the radio frequency spectrum. According to a very recent
research project aiming at finding out about the activity levels
observed on several amateur bands during times of the day when they are
supposed to provide good communications , fewer amateurs are now on the
air at any given time than five, ten or even fifteeen years ago. The
reason for this lack of motivation to go on the air seems to be related
to the fatal attraction of the Internet, as a leading amateur radio
official of a national ham radio organization told me recently , but he
also added that the trend seems to be taking a reverse path now, as some
newcomers to the amateur radio hobby are becoming very active on the air
using the digital communications modes that link ham radio and computers
in such a nice way...
Item five: A visit to Arnie's workshop, where a homebrew type power
supply is laying on top of one of the tables, still unrepaired. This
linear supply is rated for 20 amperes at 13,8 volts continuos service,
and up to 25 amps intermittent, but it was generatinga very bad hum on
the transmitted audio when running a 100 Watt HFtransceiver, so
something is really wrong with it.
I talked on 2 meters with my long time friend Luis Rodriguez, CO2LR, and
we discussed possible causes of the poor regulation of the supply. Among
the suspected causes I have yet to give a clean bill of health to the
big electrolytic filter capacitor , because those capacitors show a
marked tendency to loose their capacitance after 10 or more years of
service.
Luis advised to just go ahead and replace the big 68000 microfarads at
50 volts DC capacitor , when I told him that the supply was now about 20
years old.
Other components to check carefully are the two big series pass NPN
power transistors, each rated for 25 amperes of collector current. As
always when doing this kind of major repair work, I look at the
possibility of doing improvements to the original circuit
design,because, like in many other instances this supply was designed
perhaps more than a quarter century ago, something that is easy to
appreciate when you look at the printed circuit board that contains the
actual voltage regulator circuit.. it is an all discrete components
board, with individual transistors, capacitors and resistors, and
without any integrated circuits of any type.
Talking to CO2LR, we both came to the conclusion that because this is
not a collectors item, the performance of the supply could be improved
substantially by modernizing its voltage regulator circuit and keeping
the big , husky, well built components . Maybe by the time this edition
of Dxers Unlimited is on the air for its first airing at 21 hours UTC on
Tuesday, the power supply will be providing 13.8 volts at 20 amperes to
my HF rig when I run it at the high power setting, that requires about
18 amperes.
......
From Havana, coming to you via short wave and from 05 to 07 UTC via
Internet , this is the English language program of Radio Havana Cuba,
the name of the show is Dxers Unlimited and here is item six: Powering
your radios from batteries is sometimes the only solution available to
downtown city dwellers that receive a lot of radio frequency noise via
the AC power lines, even after installing very good quality filters with
the corresponding low inductance ground connections.
A good practical example of how reception improves when using battery
power is seen at my QTH here in Havana, where I can operate my short
wave radios with external antennas even when the 21 inch TV set is in
use just tree meters or about 10 feet away from the radio . If I
disconnect the batteries and connect the receiver to the well built,
fully regulated power supply,the noise level starting at the low end of
the AM broadcast band and moving well into past the 6 megaHertz 49
meters band, is so high that only very powerful stations can be picked
up. Switching the radio back to the 7 ampere hours 12 volts GEL Cell ,
the noise level drops dramatically, a clear indication that the noise
was coming into the receiver's circuits not by the antenna , but by
means of the AC power line. All experiments done to try to clean up
the radio frequency waveforms that reach the AC power line from the TV
set and the computers switched mode power
supplies have met with total failure... So , I was left with just one
option, build a nice , efficient battery charger, and buy a brand new
GEL CELL 12 volts DC at 7 ampere hours accumulator, a quite standard
component of house electronic alarm systems. Running my homebrew solid
state receiver, the fully charged battery lasted almost a week of heavy
service, but the same doesn't hold when powering the power hungry YAESU
FT-817, and otherwise excellent low power or QRP transceiver, that has
served me well for the past four years without any breakdowns...The FT
817 is a power hungry transceiver when in the receive position, so the
external 12 volts lead acid gel cell accumulator , even after a full
charge, will be completely discharged after about one or two days of
operation in the receive mode, and of course , much faster when in the
transmit mode.
In contrast to the power hungry FT-817, my own design HF single band 10
Watt transceiver , the Hurricane One, runs many more operating hours
from the same GEL CELL 7 ampere hours accumulator , despite the fact
that it delivers twice the power to the antenna...
......
ASK ARNIE.... Preguntaselo a ARNIE in Spanish for you to practice your
Spanish amigos... ASK Arnie is the most popular section of the show,
because radio hobby related questions sent to my e-mail address are
answered with a very fast
turnaround ... Today's question came from a listener in Canada that is
enjoying our new antenna beamed to Central North America on 6180
kiloHertz .Amigo Luigi from Toronto asks what he can do to deal with big
birds using his VHF and UHF Yagi beam and log periodic antennas as
parking places. Well, yours is a problem that is shared with a great
number of both amateur and professional radio and TV operators... Big
birds cause lots of problems to TV and FM stations, when their droppings
, that are very aggressive from a chemical point of view cause severe
corrosion to critical parts of the antennas.
One practical and very easy to implement solution to reducing the number
of birds that use your antennas to make short of long term stopovers is
to install a mockup bird of prey atop the masts.. A plastic full size
OWL or a FALCON works wonders according to those who have tried that
idea !!!
Be sure that the fake bird has all the characteristics of the real one,
including the colors of the feathers, as smaller birds seem to have good
visual recognition that helps them to determine if the bird sitting on
top of your mast or tower is the real thing or not... And in order to
survive, if they suspect that the big bird may be the real thing, they
do keep away from the antennas !!!
And now amigos after this final item about the protection of your
antennas from birds capable of breaking up the elements of VHF beams,
here is now Arnie Coro's Dxers Unlimited's HF plus low band VHF
propagation update and forecast...
BIG , really BIG sunspot still growing and now moving into a much more
geoeffective position,from where it may be sending high intensity
streams of charged particles towards the Earth during the next several
days...Solar flux has moved up to near 100 units now, and we do expect
some very exciting days ahead regarding HF propagation conditions...So
be ont he alert for possible short wave fadeouts and blackouts, abnormal
propagation conditions to the South on the AM broadcast band, and
possible 10 and 6 meter bands openings... Exciting for sure, as we are
supposed to be going trough the lower activity part of the solar cycle !!!
So , be on the lookout for abnormal propagation conditions on the AM
medium wave broadcast band, especially at higher latitudes, and also
don't expect a lot of DX to be heard on the HF bands from 6 to 18
megahertz or so, until the disturbance comes to an end, something that I
expect to happen in about two or perhaps three more days... AND, don't
forget to send me your signal reports, comments about the program and
radio hobby related questions via e-mail to arnie@xxxxxx or VIA AIR
MAIL, send a postcard or letter to Arnie Coro, Radio Havana Cuba,
Havana, Cuba
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THE INFORMATION IN THIS ARTICLE IS FREE. It may be copied, distributed
and/or modified under the conditions set down in the Design Science License
published by Michael Stutz at
http://www.gnu.org/licenses/dsl.html