Calculators: Some simple tools written in JavaScript -Máy tính: Một số công cụ đơn giản viết bằng JavaScript

Some simple tools written in JavaScript for the QRP/SWL HomeBuilder  - Máy tính: Một số công cụ đơn giản viết bằng JavaScript

Minimal input error checking.

A.  Calculate DC Voltage Divider Bias

Enter Voltage:    Enter R1:   Enter R2:      Bias voltage  =  

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B.  Calculate Inductive Reactance

Enter Inductance in uH:    Enter Freq in MHz:      XL (ohms) =  

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C.  Calculate DC Current for a Current Mirror

Enter VCC:    Enter RC in ohms      Current (mA) =  

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D.  Calculate # of Turns To Obtain a Desired Inductance on a Ferrite Torroid

Enter Inductance in millihenries:    Select Core:  FT37-43 FT50-43 FT37-61 FT50-61 FT50-77 FT114-61 FT23-61 FT23-43 FT82-43 FT114-43       Turns  =  
The AL for this ferrite core is   =  

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E.  Calculate Cut off Frequency for an RC Low Pass Filter

Enter resistor value in ohms:    Select capacitor values in uF:  0.0001 0.0012 0.0015 0.0018 0.0022 0.0027 0.0033 0.0039 0.0047 0.0056 0.0068 0.0082 0.10 0.15 0.22 0.27 0.33 0.39 0.47 0.56 0.68 0.82 0.01 0.012 0.015 0.018 0.022 0.027 0.033 0.039 0.047 0.056 0.068 0.082 0.10 0.15 0.22 0.27 0.33 0.39 0.47 0.56 0.68 0.82 1.0 1.2 1.5 1.8 2.2 2.7 3.3 3.9 4.7 5.6 6.8 10.0 15.0 22.0        3 dB down frequency (Hertz)  =  

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F.  Calculate Power in dBm and mW from Peak to Peak Voltage



Enter measured peak-to-peak voltage into a 50 ohm load:           dBm,     mW

Application Note: This web site follows the EMRFD standard for dBm power measurement. dBm = the power delivered into a 50 Ohm resistive load which is temporarily substituted at that point in the signal chain. 

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G.  Calculate  Lm and Cm For a Crystal using the G3UUR Method


Enter frequency in MHz written on crystal (series resonant frequency):

Enter measured frequency in MHz with switch open:  Enter measured frequency in MHz with switch thrown:

Enter crystal capacitance in pF:  Enter open switch circuit capacitance in pF: 

    Cm   =    femto Farads ,  Lm  =   Henries

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H.  Calculate Decibel Power Gain or Loss from 2  Peak-peak Voltages



Enter voltage 1:    Enter voltage 2      dB gain or loss =  

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I.  Calculate Decibel Power Gain or Loss from Input and Output power 



Enter input power in watts:    Enter output power in watts      dB gain or loss =  

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J.  Calculate dBm and mW from RMS Voltage (50 ohms)

Enter RMS voltage            dBm       mW

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K. Calculate Return Loss and VSWR (50 Ohms Detector) 



Enter the detector signal in pk-pk volts when the unknown port is terminated in an open circuit:    Enter the detector signal in pk-pk volts when the unknown port is terminated in the unknown impedance: 

    Return loss =   dB,   VSWR=1:   
Measurements per Figure 7.41 EMRFD.

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