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Re: [HCDX] Dxers Unlimited's midweek edition for 25 -26 Sept 2007
DXERS UNLIMITED
Dxers Unlimited midweek edition for 25-26 Sept 2007
By Arnie Coro
radio amateur CO2KK
Hi amigos radioaficionados ! This is the midweek edition of your
favorite listener oriented and technically minded radio hobby program,
our menu, as always will be full of items of interest to
people like you and me that enjoy this wonderful passtime, so follow me
amigos, as the show goes on with item one:Cuban radio amateurs will be
participating in the upcoming world wide CQ Radio Amateur Single Side
Band Contest in October… several special prefix ham stations will be on
the air using the special prefix T4, a much sought callsign among world
amateurs…among the probable ones T49C, Tango Four Nine Charlie will be
operating from Havana, T48K, Tango Four Eight Kilo, will be operating
from Las Tunas province in Eastern Cuba ,and individual Cuban radio
amateurs will , as always, be particpating in the contest from their
home QTH stations, and
I do hope that some of them will achieve excellent results, something
that started several years ago … with excellent results achieved by
among others the winner of the number one 10 meter single band entry
Walfrido, CO8WAL from Guantanamo province. I will also be operating
CO2KK my own ham station during the contest with a new pair of antennas
connected to a fast acting switch to observe how the two compare , so be
listening for CO2KK whenever 10 meter opens and if you do hear me, send
a signal report and I’ll be happy to AIR MAIL back to you a special QSL
card !!! Send mail to arnie@xxxxxx … again, arnie@xxxxxx
Item two: Moon eclipse and radio…. Any connections ?… Apparently not, as
the Moon’s distance to the Earth doesn’t change, so , as astronomers
explain, all Moon eclipses are just a visual phenomena… by the way this
item one answers questions sent by no less than eleven Dxers Unlimited’s
fans around the world amigos !!!|They all wanted to know it a Moon
eclipse has any impact on radio wave propagation on the HF bands…
Item three: We must wait patiently for an upsurge in solar activity so
that the 10 meters ham band will come back to life…once this happen the
band will be active for a few days after the increase in solar activity
, something quite normal according to solar scientists.
Item four: Possible upcoming frequency changes for North America…expect
a possible comeback of 9820 kiloHertz during the BO7 broadcast season,
but we first must study very well how the frequency of optimum traffic
curve moves up or down before taking the decision to move up to 9820
kiloHertz.
We are now operating from 0500 to 0700 our English language service to
the Pacific Coast of North America on 6000 kiloHertz, using the four by
four array of dipoles, a beautiful curtain array capable of up to 19 dB
gain over a single half wave dipole. As usual during any frequency
changes, our engineering deparment will appreciate very much signal
reports about our new to the Pacific Coast of North America frequency,
6000 kiloHertz from 0500 to 0700 UTC,and our 6060 kiloHertz frequency to
Eastern North America from 0500 to 0700 hours UTC, we are also using now
6180 Kilohertz to Central North America from 01 to 07 hours UTC.please
send your reports to arnie@xxxxxx and I will relay them immediately to
our Engineering staff…
More radio hobby related information follows in a few seconds, when
Dxers Unlimited’s weekend edition for September 25 and 26 of 2007
continues. I am Arnie Coro in Havana, stay tuned !!!
……
Si amigos, your receiver is right on one of Radio Havana Cuba’s
frequencies… and here is item three in detail !!! RHC has many good
faithful listeners around the world…
And talking about good friends, Bruce Atchinson , a faithful Canadian
listener wrote a very interesting e-mail that I ‘am going to share with
you all. He is making reference to the Grundig FR200 portable radio that
is equipped with a hand crank generator and battery charger…
Hello Arnie;
I have that radio and I enjoyed your review. I have two problems which
youdidn't mention. Even using the whip antenna, I still have image
problems.The switch for the light is also flimsy and the light flickers
when I useit. Apart from those problems, and the tuning problem, I like
that radio.
It's great for casual listening,and it is sensitive. As for the lack of
a solar panel, it's not much use here in Canada during the winter. Here
in Radway, we only get 7 hours and 25 minutes of sunlight at the winter
solstice. Summer is a good time for solar energy this far north since
we get 17 hours of sunlight on June 21. Also there's no time to charge
up batteries during an emergency since trouble usually happens suddenly
or people realise the danger too late.
I ordered the FreePlay Lifeline radio so that some children in Rwanda
could have the same radio given to them. When it comes, and if I
remember, I'll write and let you know about it.
Yours,
Bruce Atchison.
Muchas gracias amigo Bruce, thanks for the nice e-mail letter, and sure,
I agree with you about the FR200 image proble, that is due to the fact
that it is a simple single conversion superheterodyne receiver, with a
low intermediate frequency, so every 910 kiloHertz there is an image,
something that is especially noticeable while tuning bands adjacent to
were high power stations are operating. Every receiver using a 455
kiloHertz intermediate frequency will show
images
…
.
You are listening to Dxers Unlimited’s weekend edition coming to you
from Havana amigos ! Now, here is our technical topics section of the
show… A warning from an expert homebrewer of ham radio equipment.
Watch out for some banana jacks! They are lousy RF insulators and fail
at any appreciable voltages. I'm not sure, but suspect they are nylon
dyed red and black. Nylon absorbs moisture from the surrounding air and
so its losses at radio frequencies will change widely with the relative
humidity.
Then the expert provides us with a real life story about the standard
4 millimeters banana jacks.
Some years ago I was using an MFJ ATU and had just hooked up a new half
wave end-fed wire that presented a very high impedance at the ATU. I was
running only about 15 watts output from a homebrew amp on my HW-8.
Everything tuned up FB and I was pounding brass when I smelled something
hot and suddenly the SWR jumped off the scale.
Investigating, I found that the banana jack for the "single wire" feed
from the ATU had melted! Mind you, this was at a high impedance but at
only 15 watts of RF!
Banana jacks are handy connectors but since that experience I do not
depend upon the jack material to be a decent RF insulator. When I use a
banana jack and plug to handle significant RF voltages, I mount the
jacks in a good insulator (e.g. acrylic sheet) with at least 1/2 inch of
space around it before the nearest metal or grounded object.
And this nice piece of technical know how came from Ron, radio amateur
AC7AC, Alpha Charlie seven Alpha Charlie, who kindly posted it on the
GLOWBUGS e-mail distribution list.
Thanks amigo Ron for this nice and useful advice about the everpresent
among homebrewers banana plugs and jacks !
Another technical tip… also useful for homebrewers, a small low cost
component, worth only a few cents will add a lot of reliability to your
homebrew equipment, and it can also be retrofitted to existing equipment
providing extra protection against dreadful power line transients. They
look like large sized ceramic disk capacitors, and you will find them
installed in every computer power supply. Sold under many different
names, like TRANSZORBS, PEAK SUPPRESSORS and others, the power line
transient suppresors are very easy to install, requiring just two solder
points that place the component in pararell with the power line input to
the equipment.Run an Internet search for the words power line transient
suppressors and you will learn a lot more about this very useful devices
that are becoming more and more important for today’s electronics !!!
And now,here is ASK ARNIE, with a really tough question amigos
!!!Listeners from the Americas, Europe, Africa and Asia have asked me
about the possible amount of money required to put on the air a start up
amateur radio station.
Well amigos, let’s start by saying that the world’s most popular amateur
radio band is still two meters, and the most popular communications mode
is FM, that is frequency modulation. Two meter band hand held radios,
also known as handie talkies are, according to a recent research study,
the most ubiquos amateur radio equipment. The worldwide expansion of VHF
communications has helped to reduce the cost of high quality , highly
reliable hand held FM two meter band equipment, and the second hand
market is also a source of good rigs that can be bought at very low
prices. Many countries around the world now have entry level amateur
radio licences that don’t require beginners to pass the hard to learn
Morse Code tests… Those licenses usually provide operating privileges
for the two meter band, and that;s one of the reasons that the frequency
range from 144 to 148 megaHertz in the Americas and from 144 to 146
megaHertz in the rest of the world, is the most popular amateur band
since the early days of amateur radio.
Don’t think that two meters FM operation will limit you to ground wave
50 miles around your home communications… Well installed antennas with
enough gain allow the two meter band FM rigs to reach quite far, and
several amateur radio satellites have a 2 meter FM input that extends
the coverage of a little handled to thousands of mile via a space repeater .
Two meters FM will also let you connect to computerized systems that
will add lots of interesting hours to your ham radio career.
But two meters FM is not the only way to start enjoying ham radio… Entry
level HF transceivers connected to simple antennas will let you talk to
the world from your home anytime that propagation conditions on the
short wave bands are good enough. Be aware that low power HF rigs are to
be avoided by beginners and that’s a more or less generalized opinion,
as QRP or low power operation requires operating skills that take time
to develop. My own personal opinion is that a beginners HF bands rig
should provide no less than 20 Watts output into the antenna, and a 50
to 70 Watts power output will be still better, as it will let you work
stations even when band conditions are not all that good !
Si amigos, yes my friends… you don’t need to spend a lot of money to
start enjoying amateur radio,
And just before going QRT here, our exclusive and
not copyrighted HF plus low band VHF propagation update and forecast
First the update :
This past week has been nothing but absolutely terrible for HF
propagation, with a totally blank Sun , with ZERO sunspot count day in
and day out,but fortunately no geomagnetic disturbances of any
significance. For this weekend, expect very poor conditions for the HF
bands, but rather good for Long Wave and AM broadcast band Dxing.
Average solar flux for this week was about 67, and you can expect
continuing solar flux between 65 and 70 through the weekend.
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