Dxers Unlimited
Dxers Unlimited's mid week edition for 17 to 18 June 2003

By Arnie Coro

radio amateur CO2KK




Hi amigos radio, TV, FM and natural radio aficionados ! Welcome to the mid week edition of Dxers
Unlimited. I am Arnie Coro, radio amateur CO2KK, your friend in Havana, now ready to share with you
almost eighteen minutes of on the air and on the web time. Here is item one: Cuban solar expert
Angel Gonzalez Coroas described the present phase of solar cycle 23 as quote " full of surprises",
and he added in a e-mail sent to me Tuesday morning, that a returning sunspot active region may
continue to cause lots of headaches to HF radio communications systems users around the world. Angel
has done a remarkeable job by running a daily series of solar optical observations for the past
thirteen years , something that several astronomical associations and observatories have described
as an extremely valuable contribution to the study of the Sun. Now here is item two: Another
extremely simple , easy to build, low parts count receiver. This one draws only about 2 milliamps
and provides a good level of earphone volume... YES, it is a solid state bipolar transistor
regenerative receiver circuit sent in by long time Dxers Unlimited's listener Tim Rasch. More about
this very interesting regenerative later in today's program. Item three: ASK ARNIE , the number two
most popular, and almost now the number one section of the show, competing head to head with the HF
plus low band VHF propagation update and forecast will follow, answering a question sent in by
several listeners.. They all want to know more about the crank up radios and their reliability...
something that I was expecting due to the now more and more widespread availability of those crank
up powered receivers that use the Bayliss generator... Item four: If time allows will provide more
information about the copper tape vertical antenna, and as always at the end of the show, have your
notepad or tape recorder ready to copy the most up to date HF plus low VHF band propagation update
and forecast.

Stay tuned right on this frequency or keep your streaming audio connection, as Dxers Unlimited
continues in just a few seconds. Margarita Delgado is my sound engineer and producer , I am Arnie
Coro in Havana.

.....

Si amigos, you are tuned to the mid week edition of your favorite listener oriented radio hobby
program... Dxers Unlimited... Here is now item two: Dxers Unlimited's listeners provide me with lots
of valuable technical information to be shared with the rest of the worldwide audience... My good
friend Tim Rasch who now has a nice new computer and scanner, put his two new toys to work and sent
me the circuit diagram of a very interesting solid state regenerative receiver for the AM medium
wave broadcast band that uses very little current to operate, making it an ideal emergency radio !.
The receiver has an NPN very common transistor, a NPN 2N3904 that operates as a regenerative
detector stage. The radio uses a ferrite rod antenna and will pick up local and semi-local AM
stations from 540 to 1700 kilohertz, and if you add a simple link coupling to the ferrite rod, then
an external antenna may provide lots of DX signals during the local evening hours. The receiver is
very easy to build, and uses very common parts, there are no hard to find components , and part's
values are not critical at all.

If you follow the instructions closely, the receiver will operate when you connect the batteries for
the first time... Regeneration is adjustable by changing a variable resistor, and I found out after
testing the circuit in haywire fashion, that once set the regeneration control will not need to be
readjusted very often. It is a simple radio, with just two controls, one is sets the regeneration
and the other is the volume control. The radio uses very little power , in fact so little that you
may not need a power switch at all !!! It is also a very good candidate for solar power, so I
decided to test it with a 3 volts solar panel that was originally intended to recharge a power tool.
The little radio was quite happy when powered directly from the Sun, without any batteries, but as
expected when a cloud reduced the level of illumination to the solar panel, the audio output went
down immediately. Later, and still while experimenting with the breadboard circuit, I added two
nickel cadmium penlight cells, and after a few minutes, when the solar panel suffered from a lack of
illumination, the batteries took over very nicely. Having a solar and battery powered little radio
like this one is something that will help keep you in touch with the world during an emergency, when
the AC power lines fail.

In an upcoming edition of the program I will tell you more about my experiments with this little
radio, as I am going to try to see if it can work using the same system as the one recently
described here that uses another AM broadcast station as the " power source ", by tuning up and
rectiying into DC current the signal from the most powerful local station and using it to power up
the transistors of the receiver. I am not really sure if enough voltage can be developed to achieve
regeneration... If you want to know more about this and other simple radios that may be homebrewed
using readily available components and a few hours of your spare time . Just send me an e-mail to
arnie@rhc.cu, or VIA AIR MAIL send a postcard to Arnie Coro, Radio Havana Cuba, Havana, Cuba.

......

Si amigos ! This is the mid week edition of Dxers Unlimited coming to you from Havana, and now I
want to ask those of you living in the Pacific Coast area of North America for a signal report of
our new antenna array. It is now on the air on the 9820 kiloHertz frequency from 05 to 07 UTC, that
is from 9 pm to 11 pm Pacific Standard Time... Again, reception reports of the new 9820 Pacific
Coast of North America antenna will be most appreciated, send them to arnie@rhc.cu...By the way , we
start using 9820 kHz every evening at 00 UTC in Spanish, with our Central North America beam, then
at 01 UTC we switch to English with the same antenna and operate until 05 UTC with it, finally at
the end of our broadcast day, we switch to the Pacific Coast of North America new curtain array
until 07 UTC.

We do receive reports of the Central North America beam from the Pacific Coast, but everyone does
seem to observe ,as expected , a significant increase in signal strength when the beam is switched
at 05. With the new antenna, I expect that the signals received in Northern Mexico, the Rocky
Mountain States, California, Oregon, Washington state and British Columbia should be much better,
but only you there can really say the last word !!! Send your signal report to arnie@rhc.cu, or VIA
AIR MAIL to Arnie Coro, Radio Havana Cuba, Havana, Cuba.

........

Solar minimum is still expected to happen sometime between 2005 and 2007, with the most likely YEAR
OF THE QUIET SUN happening circa 2006... Forecasters are predicting a solar minimum sunspot count of
around 6 to 8 during the bottom of cycle 23, and as always they are expecting that sunspots from the
new cycle are likely to appear very soon, perhaps by the very early months of 2004... Now here is
ASK ARNIE... and the fast turnaround answers to your radio hobby related questions amigos !!! The
question today was sent by something like 20 listeners... from all around the world !!! The all ask
me about the reliability of the crank up powered radios, that are now becoming rather popular. Well
amigos, the Bayliss generator, the first succesful attempt to produce a practical , efficient ,
compact and light crank up DC generator has certainly had an impact in the consumer receiver
market... Mass production of the crank up generator and the expected further development of the
mechanism has led to widespread use of this device, that is now also used to power emergency lights
provided by high efficiency light emitting diodes, the so called ULTRA BRIGHT LEDs...

Well, here is my humble opinion about the crank up generators... Be very,very careful when buying
one of these radios... When built with the proper materials and under carefully controlled quality
control standards, the BAYLISS DC crank up wind up generator is really a very reliable mechanism.
But like everything in technology , high quality construction produces reliable equipment, while
cheap imitations will cause a lot of problems. As people prospective buyers of crank up radios will
usually want to use them as emergency stand by units, there is no point in buying the EL CHEAPO,
very low cost , low quality versions. My advice , again, to do a very careful search for the highest
possible quality crank up generators, and be prepared to pay a higher price for a piece of equipment
that will not only last much longer, but that will also be ready to operate when you really need it
most. Several well known radio manufacturers have now entered into the so called three way power
systems radios, that have a small solar panel to recharge internal nickel cadmium or nickel metal
hydride batteries, the crank up wind up Bayliss generator and an external AC to DC power supply that
is connected via a power input jack... Those three way power radios are becoming easier to find
around the world, and may become the de facto standard receivers for many areas of the Planet where
the cost of batteries is well away from the budget of the average person... The BAYLISS generator ,
with its clever mechanism that stores power in a wind up system, just like an alarm clock, provides
a rather stable low DC voltage that may last up to half an hour between crank ups, although I have
recently learned that there are several experimental BAYLISS generators designed to provide power
output during periods that extend well past the one hour per crank mark ... Si amigos, yes my
friends, oui mes amis... a well built , reliable BAYLISS crank up, wind up DC generator powered
radio is something that everyone that can afford it should have as part or the emergency contingency
kit !!!

......

And now amigos, as always at the end of the show, here is our exclusive and not copyrighted HF plus
low band VHF propagation update and forecast... Solar activity may switch again into high gear, with
former sunspot region 365 now well in sight... Many solar flares, and a huge coronal hole will
certainly have an impact upon HF propagation during the next three to five days... As a matter of
fact, it is expected that more aurora borealis and aurora australis events will occurs during this
week