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Re: [HCDX] Dxers Unlimited's weekend edition for 21-22 July Short form edition due to Pan American Games special coverage by RHC
Dxers Unlimited
Dxers Unlimited's weekend edition for 21-22 July 2007
By Arnie Coro
radio amateur CO2KK
Hi amigos radioaficionados... I am Arnie Coro in Havana, and its my
pleasure to share with you about seventeen minutes of on the air and on
the web time talking about our favorite hobby, yours and mine...
RADIO... Item one: More days with an absolutely spotless solar disk are
expected soon... not a single sunspot will be seen during a several days
period according to solar forecasters, something that tells us a lot
about the way solar cycle 23 is decaying...
Item two: Everybody knows that whenever there is a massive emergency,
cellphones simply stop working, or in the best possible scenario, it is
very difficult to communicate using them. BUT, simple , relatively low
cost amateur radio two meters and seventy centimeter bands continue to
work nicely ,providing reliable communications links that are not
dependent of the number of users of the system, like cellphones are...
That's why amateur radio continues to be regarded as a most reliable way
of communicating during emergencies, something that here in Cuba we have
found out when several powerful hurricanes , Michelle, Isidore, Lili
,Charley and Dennis struck our archipelago !!! By the way, a low cost
handheld FM two meter band transceiver and a very simple antenna system
is all you will need to stay in touch via a repeater, even under the
worst weather conditions !!!
Item three: More about the Micro Vert antenna, and how it compared to a
one meter diameter magnetic loop...Some experts are telling now that
what is actually radiating in the case of the MicroVert antenna is a
section of the outer braid of the coaxial cable feedline !
And at the end of the program, our exclusive and not copyrighted HF
propagation update and forecast... Stay tuned... in just a few seconds
more radio know-how for your enjoyment follows... I am Arnie Coro in
Havana...
.....
This is Radio Havana Cuba, the name of the show is Dxers Unlimited, and
for first time listener's information this is a twice weekly program
devoted to the promotion and development of the wonderful hobby of
radio, one you can start enjoying without investing a single cent...
just by using your already existing radios to catch far away stations,
in other words to enjoy DXING ... !!! More about the Micro Vert ultra
compact single band antenna...All I can say is that it seems to work,
after all... For the past several days I have experimented quite a bit
with the 40 meters band version of the Micro Vert, with my new PSK31
digital communications mode capability at CO2KK, and among the findings
that I wish to share with you is that it makes a nice receiving antenna
for both the 49 ,41, 31 and 25 meters international shortwave broadcast
bands... and that , of course is a bonus... as the Micro Vert antenna is
usually thought as a single band system for amateur radio work, in other
words a rather narrow band antenna... But, I found this quite by chance,
when connecting the Micro Vert's 50 ohm coaxial cable downlead to an
amateur band's transceiver that also has extended coverage of the HF
spectrum. The transceiver was tuned to Radio Havana Cuba's 9550
kiloHertz frequency, and to my surprise, the station came in loud and
clear with the Micro Vert... The Micro Vert cut for the 40 meters ham
band , used as a receiving antenna delivered excellent reception on 41
meters , as one could expect, but it did also provide quite good
reception of the 31 ,25 and 22 meters bands broadcasters...
Later I ran another detailed comparative test on the 40 meters band
while running 20 Watts of PSK31 mode , using the Micro Vert and a One
Meter Diameter Magnetic Loop , so that both antenna could be switched
very fast at the receiver's input.
Results showed that , depending on the distance from the transmitting
station, one could receive always equal or better signals on the Micro
Vert... without having to retune every few kiloHertz, as you have to do
with the Magnetic Loop...
The Micro Vert is a rather practical and compact single band solution
for radio amateurs that otherwise can't operate on the HF bands due to
lack of space for a standard size antenna system.
So far I have built three of these antennas, one for 40 meters, another
one for 30 meters and still another one for the most popular DX ham band
of them all: 20 meters. In all three cases it was not really difficult
to tune up the antennas, and results show, that even under recent poor
propagation conditions, the Micro Verts have allowed me to carry on nice
two way contacts....
The worst signal report given for the Micro Vert on 20 meters by a
station about 1500 miles away from Havana, was about 2 S units below my
very efficient quarter wave ground plane ... While the signal from the
ground plane was reported as S9...the signal from the Micro Vert after a
fast switch over was S7, an indication that DL7PE, Juergen, the inventor
of the Micro Vert was absolutely right when he affirmed that his antenna
design could make possible HF operation for many amateur operators that
live in the cities...and for that very same reason could not install
antennas for the HF ham bands.
.....
Several days in a row without a single sunspot are now not an uncommon
happening !!! Some newcomers to solar observations might have wondered
if this was normal or not... but long time observers, like my good
friend Angel Gonzalez Coroas , are not shocked by the spotless Sun...
If you want to run your own propagation forecating software , feed the
program with a solar flux figure of 70 and you will be hitting ballpark
figures during the last 10 days of July !!!
......
And now, just before going QRT , here is Arnie Coro's Dxers Unlimited's
HF propagation update and forecast... CQ magazine's VHF contest is in
progress as you are hearing this show, and there are good chances of
Sporadic E openings for the participants to enjoy. Solar flux at rock
bottom levels near 70 and no sunspots in sight on either side of the
Sun...Few chances if any of maximum useable frequencies going above 20
megaHertz, except perhaps via Trans Equatorial Propagation.. Hope to
have you all listening to the mid week edition of Dxers Unlimited next
Tuesday and Wednesday UTC days amigos !
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Preorder your WRTH 2007:
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