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May 11 2010

RFC Show Notes Episode 028

00:00 Opening Theme  
01:02 Introduction Greetings to the hams working the California forest fires.
03:10 Feedback Tim, KI6BGE, writes about his first radio, a Yaesu FT-747GX, and his first hand-held, an FT-60R, and other rigs. He also asks about cross-band repeating through the FT-8900R in his car.

Damon, NN7B, says Richard is his ham hero, and also listens to the Linux in the Ham Shack podcast. He was having a problem downloading the first episode, but that should be sorted out now.

Joe, NE2Z, enjoys both podcasts, and made a donation. Thanks, Joe!

Bob, KB3OQY, likes the podcast and learns something new in each episode. He also made a donation.

10:43 Donations Thanks to Joe NE2Z and Bob KB3OQY for their donations. If you find anything useful in an episode of Resonant Frequency, consider donating a dollar. That's less than a gallon of gasoline.
13:00 Song “Voodoo Queen” by Tommy Dardar, from the album “Blues Fool”
13:55 Buzzword Memory effect – reality or myth?

If you partially discharge a nickel-cadmium battery (NiCad), and recharge it, it may “remember” that point of discharge as it's fully discharged state. The best practice is to fully discharge a NiCad battery pack before recharging, and avoid the use of rapid chargers. A related phenomenon is “lazy battery”, where the battery appears to have a full charge, but becomes depleted rapidly when put to use. This is often caused by frequent overcharging, and may be cured by several deep discharge/recharge cycles.

20:29 Song “Wasn't That Enough” by Janiva Magness, from the album “Bury Him At The Crossroads”
22:01 Topic Nicad batteries.

This topic was suggested by several messages on the forums.

The abbreviation NiCad is a registered trademark of SAFT Corporation.

Advantages: lower weight, good charging efficiency, smaller variations in terminal voltage during discharge, low internal resistance, non-critical charging condition. In theory, a nicad battery may be charged and discharged up to 1000 times.

39:06   Comparison to Nickel-metal Hydride (NiMH)
40:42   Disadvantages: higher cost, toxicity, memory effect, and a negative temperature coefficient. Nicad cells are typically 1.2V, while alkaline cells are 1.5V.
45:11   Charging. The typical overnight charge, called a C/10 charge, is accomplished by applying 10% of the battery's total capacity for a period of 14 hours; that is, a 100 mAh battery takes 140 mAh of energy to charge.
53:53   Dendritic shorting.
56:07 Song “Welfare Blues” by Kirk Fletcher, from the album “Shades of Blue”
58:25 Conclusion Email Richard at kb5jbv@gmail.com

Twitter: twitter.com/kb5jbv

KB5JBV on D-Star via port C on the NE5R repeater.

Opening theme music is “Give It All Away”, by midliFeCrisis, from the album “Live from the Loft” available at http://www.podsafeaudio.com

Closing theme music is “We Gotta Go” by David Henderson at Podsafe Audio.

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