# Online RF Calculators by Federal Custom Cable

Online calculators are a great convenience even in the 'The Age of the Phone App.' Website-based calculators have the advantage of being accessible from any device, and without having to download and store it in memory. Federal Custom Cable has a fairly extensive collection of basic electrical, RF and microwave type calculators. They are all conveniently listed on a single page, as can bee seen at the left (I did a screen capture with all the categories expanded).

Before using any calculator I have never used before, I validate its accuracy with known quantities. Here are a few examples of the calculators, with parameters entered to quickly check the results.

The first one is a VSWR-to-Return Loss converter, where I input a number that every RF engineer and technician should have memorized for easy reference: 1.458:1 in VSWR equals 14.58 dB in return loss. Note the same numerals are used with just a shift in the decimal point.

VSWR-to-Return Loss Calculator

In these days of surface mount components, fewer and fewer people need to be able to decode resistor color stripes. The old mnemonic I have always relied on, albeit highly unacceptable in today's special snowflake world, is "Bad(black=0) Boys(brown=1) Ravage(red=2) Our(orange=3) Young(yellow=4) Girls(green=5) Behind(blue=6) Victory(violet=7) Garden(grey=8) Walls(white=9)." My excuse is that I'm just south of 60 years old and was taught it by a hardened U.S. Air Force technical school instructor (or maybe it was even before that by a hardened master electrician in my electrical vocational classes in high school). Regardless, if you can't remember the color band numbers, FCC is there to help.

4-Band Resistor Color Code Decoder

Another relationship all RF Cafe visitors should know is that is free space with a relative dielectric constant of 1, the wavelength of 300 MHz is 1 meter. The equivalent in English units is 3.28 feet. One full wavelength is 360 degrees.

Electrical Length Calculator

Posted February 16, 2017

 About RF Cafe Copyright: 1996 - 2024Webmaster:    Kirt Blattenberger,    BSEE - KB3UON RF Cafe began life in 1996 as "RF Tools" in an AOL screen name web space totaling 2 MB. Its primary purpose was to provide me with ready access to commonly needed formulas and reference material while performing my work as an RF system and circuit design engineer. The Internet was still largely an unknown entity at the time and not much was available in the form of WYSIWYG ... All trademarks, copyrights, patents, and other rights of ownership to images and text used on the RF Cafe website are hereby acknowledged. My Hobby Website:  AirplanesAndRockets.com