Re: [HCDX] Dxers Unlimited's mid week edition for 17-18 April 2007

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

Radio Havana Cuba
Dxers Unlimited
Dxers Unlimited's mid week edition for 17-18 April 2007
By Arnie Coro
radio amateur CO2KK

Hi amigos radioaficionados around the world... welcome to the mid week 
edition of Dxers Unlimited, coming to you when the Sun is showing 
practically no signs of activity... no sun spots , a blank solar disk 
for many days, and the daily measurement of the microwave solar flux is 
at minimum levels , between 60 and 70 units, the lowest figures 
registered by microwave radiometers at any time since those measurements 
began in 1947.  So, in other words amigos, we seem to be right in the 
middle of solar minimum for cycle 23.... and that of course means that 
HF propagation conditions are very poor to say the least, so poor in 
fact that frequencies above 20 mega-Hertz remain totally dead for long 
distance ionospheric propagation just as if they were VHF frequencies.
But what is bad for some radio hobbyists is good for others, and due to 
the very low solar activity we are enjoying exceptionally good medium 
wave broadcast band DX conditions during the extended spring equinoctial 
season.
Item two: Noise, noise sources of all types are making reception of 
short wave signals very difficult for listeners that can not install 
external antennas well away from noise sources. That's why every time 
someone tells me that their local noise level is very high, I provide 
the following two bits of advice. Number one: Try, by all means to 
pinpoint the main source of the noise that is affecting your reception, 
and Number two: Don't think it twice,and go ahead and home brew a 
magnetic loop antenna...
Following my advice , listener Gary from Vermont, found out, using a 
very simple VHF directional antenna , that his main source of HF noise 
was very clearly coming from a specific electricity pole, where a 50 
kilovolt ampere transformer was installed. It wasn't even the 
distribution transformer that fed his house, it was almost a city block 
away, just around the corner, but , sure, it was the noise generator...
I'll tell you more about how Gary dealt with the noisy transformer and 
how you can home brew a direction finding antenna following Gary's 
experience...
Stay tuned, as Dxers Unlimited's mid week edition continues with more 
radio hobby related information , coming to you from Havana,  I am Arnie 
Coro, radio amateur CO2KK ...
.....
This is Radio Havana Cuba, the name of the show is Dxers Unlimited, and 
yes, you can listen also via our Internet streaming audio, from rhc.cu
yes, just type, rhc.cu on your browser and it will do the rest... Our 
streaming audio is on the Internet from 05 to 07 hours UTC... Now as 
promised , how amigo Gary dealt with the noisy power utilitity 
transformer that he pinpointed with his two meters band three element 
Yagi antenna.
Yes, you heard it right, Gary connected a portable three element Yagi 
antenna he built using a short length of PVC pipe and aluminum tubing to 
his two meters band handie talkie, and went around the neighborhood 
searching for the noise sources. He told me that when he turned around
the corner , the noise increased dramatically when the Yagi was aiming 
at the other street's utility distribution transformer...Arnie, he said, 
it was so clear, that there was no chance for a mistake...
I then called the power company customer service and they sent an 
engineer that had a noise finder of a different nature. His equipment 
was tuned below the AM broadcast band, and could not locate the noisy 
transformer until it was placed exactly below it, while my handie talkie 
and Yagi combination could pick up the noise source almost a block away 
from it. In fact, Gary explains, the very cooperative person from the 
power utility went to my home and asked for a diagram of my noise finder 
Yagi, because he said that he was going to build one . The next morning 
the utility crew came with a new transformer and replaced the faulty one.
Two days later, Gary said that the engineer that had worked with him to
find the noise source called on the phone to tell him that the 
transformer was opened at the repair shop and they found damages done by 
an arc
over that was due to a faulty insulator, and he also said that anytime 
that he had a noise problem he could call directly to his cell phone. 
Now, that's service at its best, and it shows that many times power 
company people learn from radio amateurs and short wave listeners when 
trying to find noise sources.
......

ASK ARNIE, the most popular section of Dxers Unlimited amigos, no doubt, 
according to your e-mail , letters and also you tell me when we have the 
opportunity of talking to Dxers Unlimited's listeners that are
also amateur radio operators. By the way, I am just giving the finishing 
touches to my new digital HF station, so soon CO2KK will be back again 
on the air using PSK31, MFSK16 and other digital keyboard to keyboard 
modes. According to propagation forecasts for the next three months or 
so, you will probably be able to work CO2KK digital on either 20 or 40 
meters, as my main HF transceiver is a very old radio that doesn't have 
the WARC bands.  ASK ARNIE today has to do precisely with a question 
sent by listeners from Canada, the USA, South Africa, New Zealand, 
Nigeria, and India. They all want to know if there are any possibilities 
of new amateur HF bands to be discussed during the upcoming World 
Administrative Radio Conference 2007, that  is to be held in Geneva, 
Switzerland at the end of the year. Well amigos, this is my personal 
point of view... all I see happening there in relation to the HF amateur 
bands is the possibility of a better realignment of 40 meters worldwide, 
but due to the extreme pressures by other users of the radio spectrum, 
and the certain decline seen on the use of the HF amateur bands, I don't 
think that any new bands will be discussed by the world's regulating 
agencies. On the contrary what I am seeing is the possibility that at a 
future WARC or World Administrative Radio Conference amateur radio may 
be loosing spectrum space now assigned to this service, because many 
government telecommunications agencies are carefully monitoring the 
present use of the amateur bands from 160 meters all the way up to six 
meters... And according to what I have heard, it is clear that the 
figures are not encouraging at all... as a matter of fact, the famous 
phrase use it or loose it may soon become a reality if radio amateurs 
around the world don't increase as soon as possible their on the air 
activities...
......

 From Havana, this is the mid week edition of Dxers Unlimited, and here 
is item four... a connector related item... Yes radio frequency 
connectors for coaxial cables are something difficult to deal with, so 
my advice is that you select the ones to use at your ham radio station 
or short wave listening post, so that they are of the best possible 
quality. Yes, good quality RF connectors for coaxial cables are 
expensive, but they will last forever it properly installed. Poor 
quality connectors are a source of headaches and they seem to fail 
always at the worst possible moment. At CO2KK my amateur radio station I 
use three types of RF connectors, the standard BNC for thin coaxial 
cables, the PL259 male and SO239 female coaxial connectors for quarter 
inch and half inch diameter cables for HF and low band VHF applications 
and the expensive N type connectors for UHF signals. All my tests with 
high quality PL259 connectors show that there
is no difference at all on 2 meters between the PL259 and the more 
expensive N type constant impedance connectors, so the obvious thing to 
do is to use the N connectors only above 150 mega-Hertz...
And by all means amigos, learn how to properly install all the RG 
connectors at your shack, it will take some time and practice to do it 
properly,but time spent learning how to install RF coaxial cable 
connectors is well worth every minute of it..
Also, any connectors that are exposed to the weather must be properly 
sealed and protected, because there is nothing worse than humidity 
leaking inside a coaxial cable ... So, when installing new antennas or 
providing maintenance to existing ones, don't forget to have at hand all 
the necessary sealing items, including special elastic tapes, silicon 
sprays and weather protection boxes. I had recently the very bad 
experience of a faulty junction box that provides the phasing to a two 
Yagi 2 meters band array, that happened because the connectors were not 
properly sealed against the weather... It took several hours, and three 
new connectors to do the repair job... that would had been totally 
unnecessary if I had installed the phasing box properly to begin with 
!!! But this was done a day before a contest, and
you know, then the new antenna was left to its own luck , only to find 
about six months later that the standing wave ratio of the antenna 
system had gone up dramatically... then it was too late... My elder son 
Arnie Junior reminded me of what I had done the day before the VHF 
contest, and how the connectors were not protected against the weather.
- Dad, he said, its your own fault, so now I must take the whole array 
down and do a complete repair job for you. But this time , the antenna 
system will last for at least three years, that is the maximum time that 
we have found out that an antenna in Cuban weather will last without a major
overhaul of the weather protection for the RF coaxial cable connectors !!!
.....

And for those of you that have asked about our Internet audio in 
English, here is again the information on when and how to listen to it. 
The English language program is on the Internet streaming audio from 05 
to 07 Hours UTC, and the URL of the site is very simple, just rhc.cu, so 
you need only to type rhc.cu on your browser and that will take you to 
the web site, then click on the loudspeaker icon, and that's it...
Now as always at the end of the program here is Arnie Coro's Dxers 
Unlimited's HF plus  VHF low band propagation update and forecast...
Solar activity at rock bottom levels, with extremely quiet geomagnetic 
field conditions. |Sporadic E spring-summer season due to begin in 
around two weeks from now or maybe earlier, so watch for signs of low 
band TV channels skip signals.Expect excellent nighttime AM broadcast 
band conditions , but now they may be slightly spoiled as spring 
thunderstorms start to generate static crashes that make reception 
difficult especially during the summer season. Don't forget to send me 
your signal reports and comments about the program to arnie@xxxxxx, 
again arnie@xxxxxx or VIA AIR MAIL to Arnie Coro, Radio Havana Cuba, 
Havana, Cuba
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