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Re: [HCDX] [SWL] RE: Dxers Unlimited's script weekend edition 17-18 Februrary2007
Hola Arnie,
Thank you so much for posting this and sharing it with the list subscribers.
I have not heard you on the air in muchos anos amigo, but do vividly recall
our last QSO. Be well -
Duane Fischer, W8DBF
dfischer@xxxxxxxx
HHI: Halligan's Hallicrafters International
http://www.w9wze.net
HHRP: Historic Halligan Radio Project
http://hhrp.w9wze.net
----- Original Message -----
From: "Prof. Arnaldo Coro Antich" <inforhc@xxxxxxx>
To: <odxa@xxxxxxxxxxxxxxx>; <hard-core-dx@xxxxxxxxxxxxxxxx>;
<swl@xxxxxxxxxxxxxxx>
Sent: Monday, February 19, 2007 6:39 AM
Subject: [SWL] RE: Dxers Unlimited's script weekend edition 17-18
Februrary2007
> Radio Havana Cuba
> Dxers Unlimited
> Dxers Unlimited’s weekend edition for 17-18 February 2007
> By Arnie Coro
> Radio amateur CO2KK
>
> Hi amigos radioaficioanados around the world and in space, welcome to the
> weekend edition of your favorite radio hobby program , I am Arnie Coro in
> Havana, and here is item one… its related to the ongoing solar cycle’s
> minimum… When HF propagation conditions are poor, then it’s time to enjoy
> many other aspects of the radio hobby, like homebrewing receivers ,
> installing new VHF and UHF antennas, and even attempting to do some
> interesting radio astronomy experiments like listening to planet Jupiter’s
> rather easy to pick up signals on frequencies within reach of many short
> wave receivers and using very simple , easy to install antennas . If you
> happen to have an amateur’s band Yagi antenna capable of operating on the
> 15 meters or 21 megahertz ham band, then you will certainly be able to
> pick up Jupiter’s natural radio signals regularly… By the way, they sound
> like waves slowly moving over a sandy beach, and going back again…
> Stay tuned for more radio hobby related information and know how coming to
> you from Havana. I’ll be back in just a few seconds amigos !!!
> …..
> Si amigos, sure, after many years of enjoying the radio hobby, I am still
> fascinated when setting the alarm clock for two o’clock or three o’clock
> in the morning and getting ready for yet another medium wave AM broadcast
> band Dxing session… Last evening was no exception, except that I didn’t
> need an alarm clock, because my little two years old baby Claudia likes to
> wake up around that time asking for her milk bottle… Roxana my wife woke
> up first and was already changing the baby’s diaper when my new
> super-regenerodyne receiver was already picking up its first DX station,
> one that I use as a propagation beacon, because I know the power its
> delivering to the antenna and its location East of my QTH gives a very
> good idea about ionospheric absorption especially as sunrise approaches.
> It is Radio Rebelde’s 600 kiloHertz relay in San German, Holguin province
> of eastern Cuba… The signal coming in from this station was excellent, so
> I moved up to the top end of the AM broadcast band, but checking the local
> time, and making the conversion to UTC, I sadly realized it was already
> too late to try to pick up European stations… Maybe tomorrow, as almost
> ideal AM broadcast band propagation conditions will almost surely
> continue, little baby Claudia will wake up a little earlier, and I will be
> able to pick up at least one or two Europeans, that by the way, for your
> information, in case you are not familiar with that fact, operate on a 9
> kiloHertz channel spacing, so their presence is many times learned by the
> whistling heterodynes caused by their carriers beating with stations in
> the Americas that operate on a 10 kiloHertz channel spacing. The new
> super-regenerodyne, especially built for the low ebb of the solar cycle,
> runs the regenerative detector in the frequency range from 100 to 500
> kiloHertz, so tuning up the whole AM broadcast band required splitting it
> into3 segments, starting on 520 kiloHertz and ending slightly above 1700
> kiloHertz. Lacking the quartz crystals for the frequency conversion, I
> used a highly stable Franklyn type oscillator for the first conversion
> with excellent results. To receive the segment from 520 to 920 kiloHertz,
> the Franklyn oscillator works at a fixed frequency of 620 kiloHertz,
> something that is not a very nice solution because it completely blocks
> reception on several channels… The segment from 920 to 1320 kiloHertz,
> requires the local oscillator of the first conversion to operate on 1020
> kiloHertz, and here again several channels are blocked. The third and last
> segment of the AM band , from 1320 to 1700 kiloHertz requires the local
> oscillator to operate on 1420 kiloHertz, so I have the same problem with
> several channels lost to the presence of the local oscillator signal
> within the passband of frequencies that I want to listen to… But, let me
> say that despite this design flaw, of which I was fully aware, the
> sensitivity and selectivity of this AM broadcast band receiver is simply
> amazing. The operation of a regenerative detector at frequencies as low as
> 20 kiloHertz makes the control of regeneration as smooth as one can
> imagine, so you can operate the detector at its highest selectivity
> setting allowing for single side band reception, something quite useful
> when hunting for transatlantic AM band DX stations. Now that I have
> obtained such an interesting experience with this radio, a new one will be
> built, in which the AM broadcast band will be up converted to the
> frequency range from 28 to 29.2 megaHertz…, using a specially designed
> quartz crystal controlled converter and a double balanced mixer… The “tail
> end” of this up converter is going to be my single band 10 meters
> transceiver, that due to the diminishing solar activity will see little
> use to communicate during the next several years, but could play a useful
> role as yet another AM DX receiver tail end… By the way, the upconversion
> needed a single quartz crystal for the local oscillator, that fortunately
> happened to be in my junk box !!!
> …….
>
> Yesterday I made contact with two long time ham radio friends, one was
> vacationing in the Caribbean and talking to me on 17 meters from the
> balcony of his hotel room, using a helically wound antenna just 2 meters
> high… and the other was enjoying a stay with one of his daughters that
> lives in a farm and was using a real long wire antenna, no less than 400
> feet long… We had very nice QSO’s, and for those of you that are not
> familiar with that term, its an abbreviation for a two way contact used by
> the early days radio operators… I’ll have a bit more time to be on the air
> during the next 10 days or so, and expect to have many more opportunities
> of meeting with ham radio operators around the world …The best bands for
> making contacts during the winter season are, 17 and 20 meters during
> local daytime hours, and 40 and 80 meters during your local evenings, but
> we may see brief openings on 15 meters too.
> …..
>
>
> Now here is the very popular technical topics section of the program…
> Operating your radios from rechargeable batteries requires taking care of
> them, so that they will really last the number of expected cycles. It is
> amazing to see how expensive rechargeable batteries are sometimes turned
> into worthless units because their owners didn’t take proper care of them…
> Gaining knowledge about the characteristics of nickel cadmium, nickel
> metal hydride or lithium ion rechargeable batteries is very useful ,
> because if you apply the know-how, your batteries will live a lot longer.
> My advice is that you simply forget about nickel cadmium batteries, and
> buy, from now on, nickel metal-hydride units,as they can provide more
> operating time on the same size of battery, and also don’t have the so
> called memory effect of the nickel cadmium old technology batteries.
> Recent advances in the design of chargers for the nickel metal hydride
> cells make possible a much longer useful life of those units.
> And don’t forget that the lithium-ion batteries do require a special
> charger and can not be charged with any other type of charger, as they may
> be destroyed or even explode if improperly charged…
> Also, let me add that I prefer to run my receivers, whenever possible,
> using batteries, as by using them, noise coming in from the power line is
> simply reduced to zero !!!
>
> …….
> Receiving here lots of nice e-mail messages, post cards and letters here,
> and also a few FAX letters too. Keep them coming amigos, is always nice to
> read your comments about the program that are full of new ideas to make
> Dxers Unlimited a bit better on every new edition.
> Item three: The ultra compact dipole antenna that I talked about here
> recently edition here on Dxers Unlimited continues to bring in lots of
> questions among listeners around the world. The most frequently asked
> question about this topic, was if this could be designed as a broadband
> antenna, and the answer amigos is NO, the ultra compact dipoles designs
> are narrow band antennas, that most be built for operating on a single
> amateur radio band if you want to transmit with them, but that may be used
> for short wave listening over a much wider range of frequencie.Amigos
> Lester, Charlie and Albert, frequent Dxers Unlimited listeners asked thee
> possibility of using the compact dipole in a vertical configuration to
> obtain a lower radiation angle ... Si amigos, yes, you are right, the
> compact inductively and capacitively loaded dipole is ideal for installing
> it in a totally vertical or sloping configuration. As a matter of fact, I
> have just recently seen a commercial antenna design that follows that idea
> pretty closely...But personally I prefer to use this antenna as a very
> efficient sloper, because it provides a small but significant gain in the
> direction towards which the wire is sloping.
> The ideal sloping angle is between 30 and 45 degrees, in order to form the
> best possible directional pattern with the ground reflection...
> ……
> A quick reply to a question sent to our ASK ARNIE section of the show… Yes
> amigo Craig from Toronto, Canada, you are absolutely
> right in your analysis… not all compact fluorescent energy saving
> light bulbs are created equal, in other words you may install new ones
> that are extremely quiet , that is they almost don’t generate radio
> frequency interference at all,while others similarly rated may wipe our
> short wave reception far away from where the energy saving light bulb is
> installed… And don’t be surprised with some commercial brands of energy
> saver fluorescent causing problems with your TV set and VCR remote
> controls too… In more than one occasion I have seen remote control systems
> that work using infra red signals go crazy when an energy saver light bulb
> was installed near the TV and VCR … Things returned back to normal by just
> turning the light OFF !!! Of course that the only cure for the problem is
> replacing the energy saver with a better quality one, or even better yet,
> try one of the new Ultra Bright Light Emitting diode lamps, but check that
> they don’t use a switched mode power supply inside the bulb, before buying
> it…
> _______________________________________________
> List Administrator: Duane Fischer, W8DBF (WPE8CXO) **For Assistance:
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