K7TJO Metric to imperial calculator Feet inches and fractions of an inch
Element length scaling calculator for scaling the antenna you read about to the frequency you want with the materials you have.

Inches and meters Javascript Wavelength Calculator

Input frequency in mhz Decimal Inches Feet and Inches
Wavelength in meters
Wavelength in cm
5/8 Wavelength in cm
1/2 Wavelength in cm
1/4 Wavelength in cm
1/6 Wavelength in cm
1/10 Wavelength in cm
4/3 Wavelength in cm
λ decimal feet
5/8λ decimal feet
1/2λ decimal feet
1/4λ decimal feet
1/6λ decimal feet
1/10λ decimal feet
4/3λ decimal feet
Wavelength in inches
5/8 Wavelength in inches
1/2 Wavelength in inches
1/4 Wavelength in inches
1/6 Wavelength in inches
1/10 Wavelength in inches
4/3 Wavelength in inches
For folks with only old tapes and rulers.
λ
5/8 λ
1/2 λ
1/4 λ
1/6 λ
1/10 λ
4/3 λ (Hentenna circ.)
To calculate electrical wavelength, change the velocity factor.
Velocity Factor
Things to notice: try frequencies 149.9, 299.7, 494, and 983.5 with no velocity factor.
Try 142.38 284.8 and 468 with 95% end effect factor. Notice the resultant wavelengths.
These numbers should look familiar by now...
top | next scaling K7TJO

Calculator for converting feet to inches and meters and back including fractions!

Enter the data you have. The rest will change. If it doesn't change right away, click the calculate button closest to the data you entered.





decimal inches Or:
decimal feet
 meters     
centimeters

You can even put in the feet and inches and fractions of an inch below
If the calculations don't happen as expected, try clicking the calculate buttons a second time.)
feet inches:

 

 

 

 

 

 

 

 

 

K7TJO top | back handy metric--imperial converter

Element length scaling including wire diameter

For linear elements only, not for antennae with corners :-)

Formulae from www.cebik.com/vhf/scales.html

Each Element requires a separate calculation as it is NOT a linear function.

Half wavelength elements scale directly as the ratio of wavelengths.
Elements longer than 1/2 wavelength will vary in the direction of the change in wire diameter. Fatter → longer.
Elements shorter than 1/2 wavelength will vary inversely with the change in wire diameter. Fatter → shorter.
AWG
Size
Dia.
Inches
Dia.
mm
18.0403 1.0236
16.0508 1.2903
14.0641 1.6281
12.0808 2.0523
10.1019 2.5883
8.1285 3.2640
Original design frequency MHZ WL0/2
m
ft
Original Diameter
Inches
  mm
  AWG*
Original element length
feet
inches
meters
New design frequency MHZ WL1/2
m
ft
 New   diameter
Inches
mm
  AWG*
Scaled length at New Frequency and New Wire Diameter
feet
inches
meters
Ω Element Reactance    λ10 =    while L1/L0 =

λ/2 ft Plus DELTAL = ft
Scaled length at New Frequency and New Wire Diameter


AWG lookup. Enter either the guage or the diameter in inches and the other will change to match.
AWG* number diameter inches
*In the A.W.G. system, each size is 1.122932195663452 times the diameter of the next smaller size, based on an original concept of 40 sizes in arithmetic progression ranging from .460 in.(#0000) to .005 in.(#36).
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