QUICK AND DIRTY BALUNS


     Whenever a balanced load like a dipole is connected to a unbalanced load like coax, we insert a gadget called a BALUN. It's fairly obvious where the name comes from: BALanced to UNbalanced. The basic idea in its use is to be sure that the RF current goes into the antenna and not back down the outside of the coax. Did you ever hear of a ham complaining about RF in the shack? Or, getting a shock off the mike? This was probably some of the RF getting on the outside of the braid of the coax and becoming a problem.
   
     One of the problems with the RF on the outside of the braid is the effect it has on the antenna radiation pattern. The coax becomes part of the antenna and radiates at cross purposes to the main part of the antenna. This distorts the pattern and can cause for a ham's life to be miserable.

     Gather around and let's get down and dirty solving the problem. Let's make a BALUN! A quicky solution that will probably work is to start with 18 to 21 feet of RG8 type coax and wind it on a PVC pipe of 3 to 5 inches in diameter.  This will likely do the job for everything between 160 and 10 meters. (No guarantee.)  The secret is the 18 to 21 feet of coax not the diameter of the pipe.  Make sure to use coax that has a solid and not foam dielectric.  Try to make the turns close wound and in a single layer. If you scramble wind the input and output ends of the balun, the ends could be too close together and cause difficulty.

    If you would like to do a single band balun, the following chart has been suggested by some amateurs.

Mhz       RG-213, RG-8                  RG-58
3.5         22 FT, 8 turns                20 ft, 6-8 turns
7            22 ft, 10 turns                15 ft, 6 turns
10          12 ft, 10 turns                10 ft, 7 turns
14          10 ft, 4 turns                    8 ft, 8 turns
21            8 ft, 6-8 turns                 6 ft, 8 turns
28            6 ft, 6-8 turns                 4 ft, 6-8 turns

     This article is the result of reading of the article "UGLY BALUN" available on the web. Look up the article and examine the pictures of baluns that were sent in to the author from other amateurs.

BATTERY TIPS


    What rate should a Nickel Cadmium or Nickel Metal Hydride battery be charged at?

    The ideal Slow-charging rate for Ni-Cd (Nickel Cadmium) or Ni-MH (Nickel Metal Hydride) batteries is 1/10 of the rated capacity of the battery pack. If a battery pack is 700mAh in capacity, the ideal charge rate is 70mA for 12-16 hours (12 hours for constant current chargers - which are relatively expensive, and 16 hours for tapering current chargers, A.K.A. wall warts/wall cubes, which are usually low-cost). Charging Voltage should be equivalent to the # of batteries in the pack X 1.5v. A 4.8 volt pack (made of 4
cells) gets charged normally at 6 volts. Smart chargers usually set the charge Voltage automatically; wall cubes have a pre-set output voltage, and that output can vary from product to product. Furthermore, the POLARITY of the chargers vary from product to product, so GREAT CARE must be taken to confirm that the wall charger being used is the proper item for a particular battery pack.

    Batteries will usually last longer if you Slow-charge them. In fact, almost ANY rechargeable battery will last longer if you can Slow-charge them. If a battery is constantly fast-charged, it WILL be ready for use quicker, BUT it will probably wear out faster (i.e.  it will lose the ability to store current; i.e. it will stop taking a charge)
 
      info@all-battery.com
      1292 Kifer Road, Unit 807
      Sunnyvale, CA 94086 USA

ICE CAMPAIGN


We all carry our mobile phones with names & numbers stored in its memory but nobody, other than ourselves, knows which of these numbers belong to our closest family or friends.
If we were to be involved in an accident or were taken ill, the people attending us would have our mobile phone but wouldn't know who to call.  Yes, there are hundreds of numbers stored but which one is the contact person in case of an emergency? Hence this "ICE" (In Case of Emergency) Campaign.  The concept of "ICE" is catching on quickly. It is a method of contact during emergency situations. As cell phones are carried by the majority of the population, all you need to do is store the number of a contact person or persons who should be contacted during emergency under the name "ICE" ( In Case Of Emergency).. The idea was thought up by a paramedic who found that when he went to the scenes of accidents, there were always mobile phones with patients, but they didn't know which number to call.  He therefore thought that it would be a good idea if there was a nationally recognized name for this purpose.
In an emergency situation, Emergency Service personnel and hospital Staff would be able to quickly contact the right person by simply dialing the number you have stored as "ICE."
For more than one contact name simply enter ICE1, ICE2 and ICE3 etc. A great idea that will make a difference! Let's spread the concept of ICE by storing an ICE number in our Mobile phones today!
This idea was suggested by one of our Florida ECs.

SMOKING ANYONE?


Heard in the middle of a Southwest Airline flight. "Ladies and gentlemen, if you wish to smoke, the smoking section on this airplane is on the wing and if you can light 'em, you can smoke 'em."

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