Re: [HCDX] Dxers Unlimited script for 23-24 January 2007

["Prof. Arnaldo Coro Antich" <inforhc@xxxxxxx>]

Dxers Unlimited
Dxers Unlimited’s mid week edition 23-24 January 2007
By Arnie Coro
Radio amateur CO2KK

Hi amigos radioaficionados , its nice to have you all listening to this 
  mid week edition of this radio program that is entirely , absolutely 
devoted not to one specific aspect of the hobby, but to all the more 
than 80 ways that you and I enjoy it ! I am Arnie Coro, radio amateur 
CO2KK , your host here in sunny Havana and here is today’s menu:  7040 
kiloHertz,yes write it down, because 7040 kiloHertz is  the QRP spot 
frequency where low power enthusiasts gather to challenge operator’s 
skills while running extremely low power transmitters on the 40 meters 
amateur band, the one that does remain open during the local evening 
hours… Then moving ed up a bit to the 41 meters international broadcast 
band, sure enough ! several nice DX stations provide armchair copy too. 
   And by the way,  late in the evening listening or operating HF ham 
radio equipment is also much better due to a general reduction in man 
made noise !!! Item two Monitoring the low band TV channels provides 
very early warning of an Sporadic E event in progress and do remember 
that sporadic E events may happen at anytime , not just during the two 
peak seasons … Item three: one of the main topics discussed by Cuban 
hams is “Amateur radio operations during emergency situations”, and 
there are some very interesting comments from Cuban amateurs that have 
had first hand experience keeping communications operating even during 
the middle of a category four hurricane... Now as the hurricane season 
approaches, Cuban radio amateurs are getting ready to participate in a 
nation wide emergency drill, in order to test the readiness of our 
stations to handle weather related and emergency traffic in case we are 
hit by a storm.
Next item coming up: Yes, I won’t forget of including ASK ARNIE in every 
Dxers Unlimited that goes on the air, because, according to your e-mail 
messages and letters, it is certainly the most popular section of the 
program closely followed by Arnie Coro’s Dxers Unlimited’s HF plus low 
band VHF propagation updates and forecast.. If time permits, I will also 
include today our tips and techniques section, as it is becoming quite 
popular too..
Standby for more radio hobby related information, coming to you from Havana…
I’ll be back in just a few seconds … I am Arnie Coro in Havana...
….
You are listening to Radio Havana Cuba, the name of the show is Dxers 
Unlimited, and yes, we do encourage listener’s feedback, as a very 
effective way of improving this program, send your comments, opinions, 
and ideas on how to make Dxers Unlimited better directly to my computer 
… send mail to arnie@xxxxxx, again, slowly and phonetically, 
arnie@xxxxxx, and if you are not yet in cyberspace, just drop me a 
postcard to Arnie Coro, Radio Havana Cuba, Havana, Cuba.
Now here is ASK ARNIE… THE most popular section of this show. Today ‘s 
first question came from England.. listener Pat wants to know if he can 
adapt a discarded cellphone for amateur radio use. Well amigo Patrick, 
thanks for a very nice question, as first, second and third generation 
cellular phones are now becoming an environmental problem in many 
countries, because technology evolves into much more sophisticated 
systems that require different cellphones to operate with them. The only 
amateur radio band that is near to the older and still in use cellphone 
band around 900 megaHertz is not authorized by telecommunications 
administrations at a worldwide scale, as a matter of fact, only a few 
countries authorize their amateur radio operators to use the 900 
megaHert band, the one that is close enough to the first cellphone band 
to make a conversion practical. According to what I have seen inside 
discarded cellphone sets, the only possible approach for converting them 
into ham radio transceivers for the 900 megaHertz band is by means of 
software access to the programming of the cellphone set, and apparently 
some radio amateurs have already achieved positive results with some 
specific types of older technology cellphones… By the way amigo Pat, a 
much easier conversion from new information and communications 
technologies professional equipment to amateur radio applications can be 
achieved with the so called WI-FI wireless networking equipment, that 
can be easily adapted for ham radio use !!! Question number two: Came 
from Norway, where listener Olaf is picking up our 6000 kiloHertz and 
6180 kiloHertz transmissions just after midnight his local time.
Olaf wants to know why is it possible to pick up Tropical Band stations 
from Latin America at his QTH near Oslo with such good signals, and he 
mentions picking up Radio Rebelde on 5025 kiloHertz very clearly after 
the station installed its new transmitter and antenna.  Well amigo Olaf, 
Tropical Band signals will continue to propagate better and better as 
solar activity continues to move down towards the end of solar cycle 23. 
When solar flux figures between 70 and 80 units prevail for many days, 
ionospheric absorption is at a minimum and that will certainly help 
signals below 5 or 6 megaHertz propagate much better. Another important 
factor regarding low frequency propagation is the connection between 
geomagnetic latitude and signal attenuation, something that has puzzled 
scientists for many years. So, the good news for you up North, is that 
lower solar activity will improve your reception of Tropical Band 
stations for at least the next three or four years amigo !!! When old 
man Sol comes back into high activity, ionospheric absorption will 
increase and Tropical Band signals will not propagate so well during 
solar maximum years . Closely following the pattern seen on the 60 
meters Tropical Band, international shortwave broadcast stations 
operating on the 6 megaHertz or 49 meters band will be achivieng much 
better coverage during the local evening hours, and all along the night 
path from their location.
Question number three: This one came from Kansas, USA, listener Barry 
ASKs ARNIE about static electricity charging his antenna all the time, 
and the problems associated with sudden sparks coming from the antenna 
even when its disconnected… Well amigo Barry, here is my advice… install 
a good ground system at your location, even a single ground rod , well 
driven into the soil of the garden will work, and then buy a pair of 10 
kiloOHms two watt carbon resistors and connect them between the antenna 
and ground… The 5 kiloOhm effective resistance will continuosly drain 
the static electricity picked up by your antenna to ground, saving your 
radio receiver’s front end solid state devices from a quick death, 
caused by the static discharging trough the radio, as it has 
unfortunately happened to you already… My advice is that you connect the 
antenna to the radio only when you are using it, and at any signs of 
even a far away thunderstorm or the presence of CUMULUS NIMBUS type of 
storm clouds, disconnect the radio and start reading or assembling your 
new homebrew radio project !!!
Static electricity discharging to ground trough your radio’s very 
delicate solid state devices will burn them up, as many solid state 
receiver users have learned the hard way. My latest HURRICANE TWO ham 
radio transceiver, intended to operate during emergencies has a unique 
front end protection, provided by the use of a vacuum tube radio 
frequency amplifier stage, that is much more immune to static damages 
than solid state transistors of any type.
Although the vacuum tube stage requires an additional 24  volts DC power 
supply, the protection provided is well worth the additional components 
required !!!
By the way amigos, don’t forget that specially during the summer 
thundestorm season,and at anytime, it is always a very good practice to 
keep all your radio and electronic equipment disconnected from the 
antennas, ground systems and power line when they are not in use, and as 
I said a while earlier, it is also extremely good practice to disconnect 
all radio equipment whenever a thunderstorm is approaching !!!
….
TIPS and TECHNNIQUES is fast becoming popular among Dxers Unlimited’s 
worldwide audience and cybersurfers that read my scripts via the 
INTERNET… so, I am trying to include this section in almost every 
program.Today’s tip : When you are going to use any radio equipment 
connecting it to an automobile or truck electrical system as a power 
source, STOP, STOP, STOP, before doing it, and build yourself or ask an 
electronic hobbyst friend to assemble for you a well protected 
interface… I have seen too many radios, handie talkies, cellphones and 
CD portable players killed by connecting them directly to automotive 
electric systems that may generate , under the worst case scenario 
conditions, voltages as high as 17 or even 20 volts from alternators 
that are not properly regulated… The typical automotive electric system 
goes normally up to 15 or 16 volts to be able to charge the battery, so 
any electronic device that is not properly protected against such high 
voltage will simply be killed sooner or later by the overvoltage damage.

Before connecting any radio or electronic equipment to a car, truck , 
airplane or boat electric system run a very exhaustive check of the 
system while it is operating and be sure that your equipment is capable 
of handling the highest voltages that are generated by the particular 
system. My practical solution to this problem for the typical 12 to 14 
volts required by amateur radio equipment , is to assemble an interface 
that provides both reverse polarity and overvoltage protection , and 
install such interface in the car, truck, mobile home, boat or aircraft, 
so that the radios are always safe from both reverse polarity connection 
and overvoltage accidents !!!
And now amigos, here is my exclusive, at the end of the show Arnie 
Coro’s HF plus low band VHF propagation update and forecast… Very quiet 
geomagnetic field now, with very low solar activity prevailing for the 
next several days…
Solar flux is expected to stay very near 80  units, and the effective 
sunspot number is 20 …I do Hope to see you all at the upcoming edition 
of Dxers Unlimited amigos !!! And don't forget to send your signal 
reports, comments about the program and radio hobby related questions to 
arnie@xxxxxx or VIA AIR MAIL to Arnie Coro, Radio Havana Cuba, Havana, Cuba


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