home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
Ham Radio 2000 #2
/
Ham Radio 2000 - Volume 2.iso
/
HAMV2
/
MISC
/
RF
/
POWER.TXT
< prev
next >
Wrap
Text File
|
1996-06-25
|
1KB
|
19 lines
This routine converts power between many of the formats that arise in
engineering - Watts, dBm, dBW etc. Data can also be entered as a voltage in V,
uV and dBuV. The impedance of the circuit must also be entered, since this
relates voltage to power. Voltage can also be entered as S units on a receiver
where I have assumed S9=50uV and each S point is 6.02 dB. Power may be entered
in units of kTB, where kTB is the noise power developed in a resistor at a
given temperature (T) in a given bandwidth B.
The user tells the program the units of input (Watts, dBm, dBW, uV, dBuV etc)
and the numerical value (ie if you have 10 Watts, you enter '1' for watts then
'10' for the numerical value). After telling the program the impedance (default
50 Ohms) and the bandwidth (default 300 Hz) the program tells you how many dBm,
dBuV etc the 10 Watts is equal to. Note that the values for impedance and
bandwidth are irrelevant if you dont care to relate say Watts to Volts.
As way of example, the program tells us that for a 300 Hz bandwidth and 50
Ohm system, 10 W is equal to 40 dBm, 10 dBW, 22.36 V, 2.23x10^7 uV, 147.0 dBuV,
a receiver signal level of S9 + 113.01 dB, and is 189.204 dB above the noise
floor in a 300 Hz bandwidth.