Radio Habana Cuba: Dxers Unlimited weekend edition for October 21, 2000
By Arnie Coro, radio amateur CO2KK
Hi amigos! With excellent HF plus 6 meters propagation conditions, and our 9820 transmitter back on the air after its annual maintenance, here is the weekend edition of your favorite listener-oriented radio hobby show. I am Arnie Coro, and here is item one: What a nice weekend for Dxing... the solar flux hovering a bit past 160 units, the ionosphere's height slightly below normal, the A index for Friday just 02 and a lot of amateur radio activity... All these factors combined make Dxing Saturday and Sunday a very enjoyable aspect of the hobby. BUT BEWARE, we may get a slight bump from a coronal hole which is now in a geoeffective position. ANYWAY, even the coronal hole-induced disturbance starts, it is not going to be, in my opinion, a big event, and it will do a little harm above the sparsely populated 60th parallel. So, follow your friend's Arnie Coro's advice and do spend a lot of time operating during the next 48 to 72 hours; you will be rewarded with quite a few excellent DX catches.
Item two: more on stealth antennas... lots of radio enthusiasts seem to need them, in order to bypass zoning regulations. There are two stealth antennas that are really easy to install and which receive no objections from landlords or neighborhood associations. I'll talk about them today here, at the weekend edition of Dxers Unlimited.
Item three: Yes you will find me on 28.500 SSB during the whole weekend, and YES, it is wonderful to communicate with amateur radio operators around the world who enjoy listening to this show. NOW, stay tuned for more radio hobby related information... Margarita Delgado is my sound engineer and producer. The station you are tuned to is Radio Havana Cuba, and I am Arnie Coro, back with you in a few seconds...
You are listening to Cuba via short wave, this is Radio Havana Cuba, the name of the show is Dxers Unlimited and here is item two in detail: I receive a lot of letters and e-mail messages requesting advice on different aspects of the hobby... from a friend in Hawaii who learned about amateur radio while listening to Dxers Unlimited, and is already now on the air from his own ham station, asking about what equipment he should install to work HF DX; from another listener in Canada, asking about how he can install an invisible antenna.... and that question also came from listeners in the USA, the UK and even as far away from Cuba as Australia and New Zealand. So, here today I will devote some air time to two of the most popular stealth antennas, leaving the third one for the next show.
Two of the most popular and efficient amateur radio antennas that can be described as stealth antennas are the flagpole and the bird feeder. Both blend in wonderfully with the environment, and when properly built, work really very well, especially on the amateur bands from 10 megaHertz and above, although they will also work, less efficiently, on the 80 and 40 meter bands. One very-easy-to-build-yourself stealth antenna is assembled from a commercial multi band trap vertical. There are several models that use slim traps, so the whole antenna can be concealed inside a PVC pipe, strong enough to be also the flagpole. In other words, you assemble your multi band trap vertical, and just slide it inside the PVC pipe. A ground rod next to the PVC pipe provides the connection to the coaxial cable braid or shield, and you can install several underground radials if that is possible. A flagpole antenna will provide excellent results on the 30, 20, 17, 15, 12 and 10 meter bands, and you can either select a commercial antenna for the bands you want, or build your own. My advice is to start with a commercial three band 20, 15 and 10 meter trap vertical that uses small diameter traps, install it, and operate for a while in order to have a good idea of how it works... If you are a nighttime operator, then my advice is to install an antenna that will let you enjoy the 40 meter band too..
There are several 40,20,15 and 10 meter trap antennas that will be ideal for this job. This is fast-track solution when you want to operate on the HF bands using a flagpole stealth antenna. If you are a dyed-in-the-wool homebrewer, another nice stealth antenna approach is a birds feeding station. You can make it look beautiful too, and as in the case of the flagpole, the bird feeder will do the two jobs, provide your ham station with a nice stealth antenna system and feed the birds nicely, too.
The third stealth antenna type, the underground ones, will be the main topic of the next edition of Dxers Unlimited. If you need to install a stealth antenna for amateur radio or short wave listener and have any doubts or want advice, just e-mail your questions to me, send mail to: arnie@radiohc.org, very easy to remember, and I will provide you with an answer as soon as possible. You can also send a postcard to Arnie Coro, Radio Havana Cuba, Havana, Cuba, and I will then answer via Air Mail back to you. Remember, a stealth antenna is much better than no antenna at all, and now that the solar cycle is in full swing, even very small antennas work well, especially on the 15, 12 and 10 meter HF ham bands!!!
Homebrew receivers might not have very good looks when they are still in their experimental stage, but once you have achieved good results, a lot can be done to make those homebrew radios look really nice. I have just finished packaging my last regenerodyne receiver, and it looks real nice... I am using a nice variable capacitor and dial combination from a World War 2 BC455 receiver. Unfortunately the receiver reached me beyond any possibility of restoration, so I removed the dial mechanism and variable capacitor, and it is now installed on the regenerodyne receiver. By the way a regenerodyne, for those of you not familiar with that term, is a receiver that uses a standard superheterodyne frequency conversion, which is then coupled to a regenerative detector stage. It is a simple receiver, as compared with a superhet, but its performance is really amazing. If you want to see the circuit diagram of one of the most popular regenerodyne vacuum tube receivers, just send an e-mail to arnie@radiohc.org, and I will send the diagram as a .jpg graphic attachment. Remember, once you are pleased with the results obtained from your homebrew radio, it is a nice idea to invest some time in improving the look of it. Then, when you show it to your friends, they will admire both the performance and the looks !!!!
And now, let's make a quick visit to Arnie's workshop. Sitting right in the middle of the main workbench is a beautiful 1960's built professional signal generator. I got this one at a hamfest, and it had a very nice cosmetic look. It is an impressive piece of test equipment. I am still looking for its technical manual, but even without it, the signal generator is now back in operation; all I had to do was to replace a fuse and a damaged electrolytic capacitor. And why do I talk about this here? Well, because those of you who are learning to enjoy homebrewing radio gear will certainly benefit from having a high quality Radio Frequency Signal Generator.... and many of them can be found at hamfests, because some people do not realize that those expensive test instruments of the vacuum tube days are really worth their weight in gold for the experimenter. Although they may have minor defects, they are usually in rather good shape, and with care they can be recalibrated if need be, restoring them to their original parameters or very near to them. By the way, this signal generator sitting right in the middle of the main workbench is a British-built Marconi FM Signal Generator TF 1066B, so if any of you Dxers Unlimited's fans has an idea on how the instruction and service manuals for this nice piece of test equipment can be obtained, please contact me via e-mail at arnie@radiohc.org, or via Air Mail to Arnie Coro, Radio Havana Cuba, Havana, Cuba. And remember this: the next time you go to a hamfest flea market, take a good look at any test instruments that may be for sale. You may be lucky, as I was, and obtain a very expensive piece of laboratory test gear for next to nothing!!!
In an upcoming edition of Dxers Unlimited, I will give you a panoramic view of what is needed to run a nice radio and electronics hobbyist workshop.
And now just before going QRT, here is news from Japan -- a DX expedition to the island or Palau in the Pacific, from next October 27th to October 31st... callsigns used will be Tango 88 Whisky X ray and Tango 88 Quebec Gulf. The nice thing about this DX expedition is that they will operate on the 6 meters band too, participate in the CQ World Wide DX SSB contest, and also operate using the PSK31 keyboard to keyboard mode.
Well, it is time now for Arnie Coro's HF propagation update and forecast. SORRY, but so far solar activity has not shown us a peak as high as expected between October 17th and October 21st... and that is something to worry about. This may be an indication that the solar cycle's maximum has just passed by during the summer, but we must still wait for the next three to five solar rotations to have a clear picture of this cycle's behavior. Anyway, conditions are, as I said at the start of the show, really very nice, and solar flux may increase to around 180 during the next two days. For radio amateur operators, GO GO GO to 10 meters.... during the local daylight hours, and even after sunset. For short wave listeners, the 13 meter or 21 megaHertz band is THE daytime band, closely followed by 16 meters.
Enjoy radio amigos, go on the air, call CQ DX a lot, and if you are not already a ham, follow our friend in Hawaii and take your amateur radio license test as soon as possible so that you can enjoy the best months of solar cycle 23!!!
Arnie Coro CO2KK
Havana, Cuba
October 21, 2000Postal address:
Arnie Coro, "Dxers Unlimited"
Radio Havana Cuba, Havana, CUBA
e-mail: arnie@radiohc.org
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