Consider reading, Decibels, a Refresher, in the column Contesting for Fun written by Brian Kassel in the September/October 2002, Volume 30 Number 5 issue of the National Contest Journal. If I'm going to test Micro dB Theory and its relationship to improved RadioSport scoring then I need to understand a fundamental measurement -- the decibel as a basic communications yardstick (2002, Kassel).
The author submitted a basic calculation to ascertain the difference between two power levels instead of complex operations. His method is understandable to my inner engineer and Kassel stated his calculation is accurate to plus or minus a decibel or so (2002).
Kassel (2002) suggested the following as a quick evaluation method to determine gains, losses, etc.
1. Every time power is increased two times then add 3 decibels.
2. Every time power is decreased to 1/2 times subtract 3 decibels.
3. Every time power is increased four times then add 6 decibels.
4. Every time power is decreased to 1/4 times subtract 6 decibels.
5. Every time power is increased to ten times add 10 decibels.
6. Every time power is decreased to 1/10th times subtract 10 decibels.
Kassel (2002) cited an additional example when increasing power from 5 watts to 100 watts as adding up dB values: 100 watts / 5 watts = 20 times increase also 5 watts times 10 (10dB) = 50 watts then 50 times 2 (3 dB) = 100 watts. Therefore 10 dB plus 3 dB equals 13 dB increase of concentrated radio wave energy toward your target area.
Kassel (2002) presented another problem such as increasing one's power from 100 watts to an output of 400 watts as measured at the transmitter: 100 watts times 4 (6 dB) = 400 watts or 100 watts times 2 (3 db) = 200 watts then 200 watts times 2 (3 dB) = 400 watts. Therefore 3dB plus 3 dB equals 6 dB as a function of increasing power at the transmitter by four times.
The author stated that one must also subtract losses within his calculation and memorize his method of quickly calculating gains, losses, etc. eventually one can learn how-to analyze an entire communications link.
I recommend reading Contesting for Fun; Decibels, a Refresher, written by Brian Kassel, K7RE in the National Contest Journal, September/October 2002, Volume 30, Number Five.
73 from shackadelic near the beach.
The author submitted a basic calculation to ascertain the difference between two power levels instead of complex operations. His method is understandable to my inner engineer and Kassel stated his calculation is accurate to plus or minus a decibel or so (2002).
Kassel (2002) suggested the following as a quick evaluation method to determine gains, losses, etc.
1. Every time power is increased two times then add 3 decibels.
2. Every time power is decreased to 1/2 times subtract 3 decibels.
3. Every time power is increased four times then add 6 decibels.
4. Every time power is decreased to 1/4 times subtract 6 decibels.
5. Every time power is increased to ten times add 10 decibels.
6. Every time power is decreased to 1/10th times subtract 10 decibels.
Kassel (2002) cited an additional example when increasing power from 5 watts to 100 watts as adding up dB values: 100 watts / 5 watts = 20 times increase also 5 watts times 10 (10dB) = 50 watts then 50 times 2 (3 dB) = 100 watts. Therefore 10 dB plus 3 dB equals 13 dB increase of concentrated radio wave energy toward your target area.
Kassel (2002) presented another problem such as increasing one's power from 100 watts to an output of 400 watts as measured at the transmitter: 100 watts times 4 (6 dB) = 400 watts or 100 watts times 2 (3 db) = 200 watts then 200 watts times 2 (3 dB) = 400 watts. Therefore 3dB plus 3 dB equals 6 dB as a function of increasing power at the transmitter by four times.
The author stated that one must also subtract losses within his calculation and memorize his method of quickly calculating gains, losses, etc. eventually one can learn how-to analyze an entire communications link.
I recommend reading Contesting for Fun; Decibels, a Refresher, written by Brian Kassel, K7RE in the National Contest Journal, September/October 2002, Volume 30, Number Five.
73 from shackadelic near the beach.