Radio Havana CubaDxers Unlimited - weekend edition for 19-20 January 2008
By Arnie Coro, CO2KK
Welcome to the weekend edition of your favorite radio hobby program, coming to you via short wave and also from our streaming audio source at www.radiohc.cu... We are also offering the opportunity of reading scripts of the program at several Internet short wave listeners, amateur radio and antennas topics e-mail distribution lists and also at our website too... go to www.rhc.cu click on English and then go to Dxers...
Here is Item One: The forecast about solar activity you heard during the mid week edition is holding up pretty well, and solar activity continues to be very low, with the ionospheric absorption index reaching also rather low values... Solar flux is hovering around … 70 to 75 units. , and the sunspot count has stayed at extremely low levels, actually at ZERO , no sunspots for the past 7 days in a row!
Item Two: Those Dxers Unlimited's listeners that have built different versions of the Micro Vert ultra compact HF antenna have sent e-mail messages telling me that the antenna is providing good reception of the adjacent international short wave broadcast bands, next to the amateur band for which the Micro Vert was actually designed and built r... For example, the 20 meters band Micro Vert, a controversial antenna design by any standards, is providing good reception of both the 19 and the 22 meter shortwave broadcastdo bands, while at the same time letting the owner both monitor and also transmit on 20 meters...although all users report that signals transmitted using the MicroVert are from minus 6 to minus 10 dB below a standard half wave reference dipole.
The 30 meters band Micro Vert is providing, again according to reports received here from listeners that have built them, good reception on the 31 and 25 meters international short wave broadcast bands...And that's something nice to know, because many of those who have built these antennas tell me that the Micro Vert was the easiest to build and lowest cost solution to the challenge of installing a short wave antenna at a location with very restricted space space available for a short wave antenna... This is a very small antenna, that can be installed almost anywhere…
Item Three: Changing his radio’s power source from a wall wart plug power supply to a very well built, fully filtered and regulated DC supply changed the way a Dxers Unlimited's listener receiver worked.
And now here is our technical topics section for today... How to choose the right type of coaxial cable for your antenna system... so that you won't waste money buying expensive cables when you really don't need them... For example, TV cable companies use several types of 75 ohm coaxial cables that are ideal for amateur radio and short wave listening use, as well as for VHF band scanning... Because the world's production of TV type 75 ohm coaxial cable is so huge as compared with the production of 50 ohm impedance cable, 75 ohm coax is much cheaper while providing the same or even higher quality on a per unit length cost basis. That's why I use 75 ohm cables at my amateur radio station for practically all applications... and I can assure you that receivers won't see any difference at all, and in the case of transmitters , a very simple impedance adapter is needed only with solid state outpur transceivers or transmitters, it is the only additional thing needed...
And now here is our technical topics section for today... How to choose the right type of coaxial cable for your antenna system... so that you won't waste money buying expensive cables when you really don't need them... For example, TV cable companies use several types of 75 ohm coaxial cables that are ideal for amateur radio and short wave listening use, as well as for VHF band scanning... Because the world's production of TV type 75 ohm coaxial cable is so huge as compared with the production of 50 ohm impedance cable, 75 ohm coax is much cheaper while providing the same or even higher quality on a per unit length cost basis. That's why I use 75 ohm cables at my amateur radio station for practically all applications... and I can assure you that receivers won't see any difference at all, and in the case of transmitters , a very simple impedance adapter is needed only with solid state outpur transceivers or transmitters, it is the only additional thing needed...
My old vacuum tube transceiver, a Kenwood TS820, doesn't even need the impedence converter , as it happily runs with 75 ohm coaxial cables easily matched by the rig’s output stage PI network. Si amigos,yes my friends, oui mes amis... whenever you have a chance of obtaining 75 ohm coaxial cable,just grab it !!! It works quite well, and for all practical purposes, it will do the job.. There are even some large diameter low loss 75 ohm cables used by the TV cable industry that will make ideal transmission lines for your VHF , UHF and low band microwave antennas, and typically the TV cable company technicians will gladly provide radio amateurs with the short ends of the big drums of cable !!!
I am very happy to say that we are operating our 100kW shortwave transmitters during our nightly broadcasts on the following frequencies, 11760, 9600 and 9550, 6060 and 5965 kiloHertz ... of those five frequencies only 6060 is in English beaming to the East Coast of North America,, and the other four are broadcasting our Spanish language program to Latin America, so if you want to polish your Spanish, pick them up and enjoy our nightly magazine show to Latin America and the Caribbean.
You can send your signal reports to me and I will relay them to our Chief Engineer ,and to our transmitting station staff for them to enjoy... Send your signal reports and comments about the audio quality too to arnie@rhc.cu, again arnie@rhc.cu , or VIA AIR MAIL to Arnie Coro, Radio Havana Cuba, Havana, Cuba...
And now amigas and amigos, just before going QRT here is our exclusive and not copyrighted HF plus low band VHF propagation forecast...Solar activity is very low, and will almost surely continue at a very low level for the next several days... Solar flux number to be used for short term HF forecasting using propagation analysis software is around 75 units... Expect very good DX conditions on the AM broadcast band, the Tropical Bands on 120, 90 and 60meters and the international short wave broadcast band on 49 meters. Radio amateur operators will enjoy nice DX on 160, 80 and 40 meters during the local evening hours... VHF openings via sporadic E if any , will be almost non existent, and if they happen they will be very short lasting... See you all at the mid week edition of Dxers Unlimited, next Tuesday and Wednesday UTC days, and don't forget to send your signal reports and comments about the program to arnie@rhc.cu via E-Mail, or VIA AIR MAIL to Arnie Coro, Radio Havana Cuba.
I am very happy to say that we are operating our 100kW shortwave transmitters during our nightly broadcasts on the following frequencies, 11760, 9600 and 9550, 6060 and 5965 kiloHertz ... of those five frequencies only 6060 is in English beaming to the East Coast of North America,, and the other four are broadcasting our Spanish language program to Latin America, so if you want to polish your Spanish, pick them up and enjoy our nightly magazine show to Latin America and the Caribbean.
You can send your signal reports to me and I will relay them to our Chief Engineer ,and to our transmitting station staff for them to enjoy... Send your signal reports and comments about the audio quality too to arnie@rhc.cu, again arnie@rhc.cu , or VIA AIR MAIL to Arnie Coro, Radio Havana Cuba, Havana, Cuba...
And now amigas and amigos, just before going QRT here is our exclusive and not copyrighted HF plus low band VHF propagation forecast...Solar activity is very low, and will almost surely continue at a very low level for the next several days... Solar flux number to be used for short term HF forecasting using propagation analysis software is around 75 units... Expect very good DX conditions on the AM broadcast band, the Tropical Bands on 120, 90 and 60meters and the international short wave broadcast band on 49 meters. Radio amateur operators will enjoy nice DX on 160, 80 and 40 meters during the local evening hours... VHF openings via sporadic E if any , will be almost non existent, and if they happen they will be very short lasting... See you all at the mid week edition of Dxers Unlimited, next Tuesday and Wednesday UTC days, and don't forget to send your signal reports and comments about the program to arnie@rhc.cu via E-Mail, or VIA AIR MAIL to Arnie Coro, Radio Havana Cuba.