DG7YBN - Low Noise Yagis
DG7YBN
Low Noise Yagis
Low Noise Yagis
DG7YBN
Low Noise Yagis
Low Noise Yagis
Online Calculators
(x)
RF Calculators
Last Update Oct. 24th 2021General Issues
Equivalent isotropically radiated power EIRP
Watts to dBm & dBm to watts
dB to numeric & numeric to dB
Watts in > Gain or Loss > Watts out
Receiver Sensitivity
Temperature to dB (NF)
dB (NF) to Temperature
μV to dBm
dBm to NF
SNR to S-Units and uV
G/T Ratio
Impedance
VSWR & Mismatch Loss
Links to other Online Calculators on dg7ybn.de
DL6WU/G3SEK Boom Correction
Yagi Stacking Distances acc. DL6WU
Antenna Average Gain Correction acc. KF2YN
Impedance of round and square Coaxial Lines
Power Splitter Coaxial Lines, Z and lengths
Watts to dBm & dBm to watts
dB to numeric & numeric to dB
Watts in > Gain or Loss > Watts out
Receiver Sensitivity
Temperature to dB (NF)
dB (NF) to Temperature
μV to dBm
dBm to NF
SNR to S-Units and uV
G/T Ratio
Impedance
VSWR & Mismatch Loss
Links to other Online Calculators on dg7ybn.de
DL6WU/G3SEK Boom Correction
Yagi Stacking Distances acc. DL6WU
Antenna Average Gain Correction acc. KF2YN
Impedance of round and square Coaxial Lines
Power Splitter Coaxial Lines, Z and lengths
EIRP
Watts to dBm & dBm to watts
dB to numeric & numeric to dB
Watts in > Gain:Loss > Watts out
Receiver Sensitivity
Temperature to dB (NF)
dB (NF) to Temperature
μV to dBm
dBm to NF
G/T Ratio
Impedance
VSWR & Mismatch Loss
Links to other Online Calculators on dg7ybn.de
DL6WU/G3SEK Boom Correction
Yagi Stacking Dist. acc. DL6WU
Ant. Average Gain Corr. (KF2YN)
Impedance of Coaxial Lines
Power Splitter Z and lengths
Watts to dBm & dBm to watts
dB to numeric & numeric to dB
Watts in > Gain:Loss > Watts out
Receiver Sensitivity
Temperature to dB (NF)
dB (NF) to Temperature
μV to dBm
dBm to NF
G/T Ratio
Impedance
VSWR & Mismatch Loss
Links to other Online Calculators on dg7ybn.de
DL6WU/G3SEK Boom Correction
Yagi Stacking Dist. acc. DL6WU
Ant. Average Gain Corr. (KF2YN)
Impedance of Coaxial Lines
Power Splitter Z and lengths
EIRP
Watts to dBm & dBm to watts
dB to numeric & numeric to dB
Watts > Gain:Loss > Watts out
Receiver Sensitivity
Temperature to dB (NF)
dB (NF) to Temperature
μV to dBm
dBm to NF
G/T Ratio
Impedance
VSWR & Mismatch Loss
Links to other Calculators
DL6WU/G3SEK BC
Yagi Stacking acc. DL6WU
Ant. AG Correction (KF2YN)
Impedance of Coaxial Lines
Power Splitter Z & lengths
Watts to dBm & dBm to watts
dB to numeric & numeric to dB
Watts > Gain:Loss > Watts out
Receiver Sensitivity
Temperature to dB (NF)
dB (NF) to Temperature
μV to dBm
dBm to NF
G/T Ratio
Impedance
VSWR & Mismatch Loss
Links to other Calculators
DL6WU/G3SEK BC
Yagi Stacking acc. DL6WU
Ant. AG Correction (KF2YN)
Impedance of Coaxial Lines
Power Splitter Z & lengths
EIRP : Equivalent isotropically radiated power
What is EIRP about?
EIRP is a term often used with the topic of RFI (Radio-Frequency Interference) and Radiation Power of Electromagnetic Fields. Simply put EIRP stands for the equivalent of fed power to an isotropic radiator (gain = 0 dBi per definition) vs. a directional antenna with certain gain over the iso.-radiator and other fed power. By referring to the iso.-radiator directional power levels in beam direction can easily be compared. In Amateur Radio use that could be comparing powers of two stations. Lets assume a DX setup for 432 MHz: one station is feeding 700 W into a 17.1 dBi antenna, the other 400 W into a 19.8 dBi antenna. Which one 'pumps' more radiation power into beam direction?
What maths are driving this calculator?
1. Conversion of Isotropic Gain of Antenna to numeric number 2. EIRP is derived by multiplication of Power in watts with numeric Gain of antenna against an Isotropic Radiator 'Gain,iso' = dBi = dBd + 2.15 dB. Example: 12.10 dBd is 14.25 dBi
Watts to dBm & dBm to watts Conversion Calculator
dBm is Decibel-milliwatt, it references power to one mW - with 0 dBm = 1 mW
• 0 dBm = 0.001 W
• 10 dBm = 0.01 W
• 50 dBm = 100 W
What maths are driving this calculator?
dB Conversion Calculator
This conversion works with GAIN and LOSSES:
• Gain 3.0 dB = 2.00 numeric
• Gain 0 dB = 1.00 numeric
• Gain -3.0 dB = 0.50 numeric
What maths are driving this calculator?
Getting a sense for numeric gain numbers as Power in Watts is multiplied with numeric Gain, see EIRP Calculator:
• 2.00 numeric = we know that 3 dB gain gives double output
• 1.00 numeric = adding 0 dB does not change anything
• 0.50 numeric = is half power out
Amplification Gain or Attenuation to Watts in/out Calculator
What maths are driving this calculator?
Power Levels in dB can be summed (gain) or subtracted (loss).
So we convert Power Input in watts to Power Level (dB) refering to 1 watt (dBw) Next we add the Power Levels of fed power and gain or attenuation block or generalised for any chain of gain and attenuation blocks the formula looks like this:
Note the rather explicite notation 'Loss_x'. This commonly would be another G_x with gain < 1.00
Finally we convert the resulting Power Level (dB) into watts again
Temperature to dB Calculator
What maths are driving this calculator?
with To = 290 K = 17° Celsius mean ambient temp. (273 K = 0° C)
And in reverse ... dB to Kelvin Calculator
What maths are driving this calculator?
with To = 290 K = 17° Celsius mean ambient temp. (273 K = 0° C)
μV to dBm Calculator
What maths are driving this calculator?
dBm is Power Level referring to 1 mW
dBm to NF Calculator Receiver Sensitivity to Noise Figure
• BW = Bandwidth
• dBm = Power Level referring to 1 mW
• To = 290 K or 17° C ambient
Using this calculator with Receiver Specs from a Data Sheets
As different S/N levels are used as well as bandwidth depends, look up those specifications
with the μV or dBm number given for sensitivity and enter to calculator form to yield a correct result
Typical numbers
• nominal BW's: CW or as SSB = from 2.4 ...3 kHz, AM = 6 kHz, FM = 12.5 ... 25 kHz
• CW Filter? => acc. filters bandwidth settings
• nominal S/N = 6, 10 or 12 dB
What maths are driving this calculator?
k = Boltzman's constant (1.3 x 10-23 J/K)
SNR to S-Units and μV Calculator
G/T Calculator
What maths are driving this calculator?
VSWR & Mismatch Loss
Z1 would be Zo or 'at Transmitter or Receiver' while Z2 could be antenna feedpoint impedance
Mismatch Loss (ML) expresses what Losses derive from connecting non similar impedances
Mismatch Loss application example:
Given a 50 ohms feedline coax of 10 m length with a loss of 1.2 dB shall be connected to a 75 ohms antenna. What is the total loss here?
The calculator puts out -0.177 dB for Mismatch Loss, the coax adds 1.2 dB, total loss is 1.377 dB.
What maths are driving this calculator?
Z2 in absolute numbers is with this we do the rest as follows
73, Hartmut, DG7YBN