Specialized on high frequency electronics for RF professionals, radio amateurs and students.

RF-Toolbox is based on the popular Electronic Toolbox by Marcus Roskosch.

This app contains some of the common tools of Electronic Toolbox but contains a wide range of additional tools, specialized for high frequency electronics, RF professionals, radio amateurs and students.

Currently RF-Toolbox consists of more than 90 tools and like Electronic Toolbox, there are more to come over the time.

Feature list:

■ PCB Trace Width (Internal and external Traces)
■ PCB Trace Resistance
■ PCB Trace Impedance (various trace types e.g. Microstrip, embedded Microstrip, Symetric and Asymetric Stripline, Wire Microchip, Wire Stripline, Edge Coupled Microstrip and Stripline)
PCB Crosstalk (Microstrip and Stripline)
■ LC L/T/Pi Match calculation
■ Coax Cable calculation (Standard and individual Types)
■ Amplifier and Attenuator cascade calculation
■ SWR / Reflection / Return loss conversion
■ Power Divider (Branchline, Ratrace and Wilkinson)
■ Capacitor Plate calculation
■ RLC Parallel, Series and Circuit calculation
■ Noise Figure conversion
■ Skin Depth calculation (various materials from Aluminum to Silver)
■ Butterworth Filter (also with plot of filter chart)
■ Chebyshev Filter (also with plot of filter chart)
■ R-C, L-C, R-L High/Low/Band-Pass Filter
■ RF Units conversion (quick conversion of frequently used units)
■ Air coil inductance calculation
■ Resistors, Capacitors, Inductors in Parallel / Series
And there is much more...
■ Aktive Filter calculation tool
■ Antenna calculation tool
■ Delta Star calculation
■ Cable length / ampacity tool
■ PTC / NTC Temperature Resistance conversion
■ AC Ohms law tool
■ Zener diode circuit calculation
■ Constant current source tool
■ ASCII Table
■ Desktop calculator
■ Resistor/Capacitor/Inductor combinations tool
■ 4-20mA conversion tool ■ Passive cooling calculator
■ Audio Oscilloscope

Please check out more screen shots on my website (WEBSITE Link on the left side).

If you have questions, please feel free to contact me by using the Support button here, inside the App or on my website.

Thank you!

Marcus Roskosch

What’s New

Version 13.0.1

This update contains several changes and improvements:

■ Additional iOS 13 compatibility

- a new File and PDF Viewer has been implemented
- iOS 13 page sheets are now supported
- and several additional changes to support iOS 13 have been implemented
- The minimal iOS Version requirement is now 10

■ Bug fixes

- Bug fixes in the C-Plate tool
- Bug fix of the Components tool which could only opened once
- Due to the new PDF Reader, data-sheets will now rotate correctly
- Printing from inside the Database tools (e.g. Transistors) no work correctly
- A bug which prevents to import Online projects was fixed (basically an iOS 13 bug)

■ SamacSys tool

I found that this tool often was underestimated. It is indeed a very powerful tool to find information like specs, data sheet and pin out of literally any component. The tool is now called Comp. Search to better suit to it's purpose. I have also implemented some improvements to this tool.

■ Attenuator tool

This tool now also calculates backwards based on the selected E-Series

■ Tables tool

- 3D Printing Filament types added
- Power over Ethernet POW Classes added

■ Circuits diagrams

One of the larger improvements is the use of the internal Circuit drawing feature for the tool diagrams. This way, the circuits (e.g. for the OpAmp Tool) benefit from the following improvements:

- Improved drawing quality
- Resistors will now either be displayed in Zig-Zag US or IEEE Style (depending on the country setting)
- Where possible, the circuits now show the calculated component values inside the diagram
- All tools now offer Printing and PDF Exporting which also includes the circuit diagram

■ Circuit Editor

- New Setting: "Adjust board to fit" under (File -> Parameters) allows to change the board size to fit the whole circuit so you don't have to move components around if the board is too small.
- Circuits can now also be printed

■ Improved File Viewer, Print and export capabilities

Either from inside the tools or from inside the File Viewer, content like the Tool results can now be exported as PDF as local file or printed

■ Other improvements

- A new Tool SMPS for calculating Flyback Transformers for Switched Mode Power Supplies as been added
- Several images have been re-created in higher quality
- The Formula tool has also been improved

In case of questions, issues or suggestions, please use the Support button inside the App of the Form on the website.

Thank you so much for your support.

Please let others know if you like this App to keep it going.

Thank you so much!

Best Regards,


Ratings and Reviews

4.9 out of 5
16 Ratings

16 Ratings

Avengerman14s ,

Electronics and RF Tools

WOW....... After a 30 year break I decided to get back into Ham Radio and Electronics I stated in Boy scouts. Needless to say my math skills were never great and now pretty much gone, my military service took its toll.

A few years ago I looked for this type of software but nothing like these were available, but tonight I found these two sets of tools and about hit the floor when I opened them, for me and others without an EE degree these tools include everything I need to not only troubleshoot equipment but now I think I’ll be able to build my own.

I cannot say enough good things about these, check them out you won’t be sorry. Now if someone could develop programming tools for ATMELs and PICs I’ll be in heaven.

Thank you for developing these awesome apps.


Powerup777 ,

Second to none

I'm a lifetime electronics technician and can testify this is what gets you going in the right direction for most of your formula needs. I appreciate that the developer continues to support the app for well over a year since I bought it. Bugs squashed before I knew it was a problem.

raybcool ,

A real electronic toolbox

What a nice professional product. I use this app weekly, saves time from not getting on a workstation just to design or validate a simple circuit.
Both RF-Toolbox Pro and Electronic TB Pro have been excellent references, and are always being improved/updated by Marcus. Thank you.


Marcus Roskosch
116 MB

Requires iOS 10.0 or later. Compatible with iPhone, iPad, and iPod touch.


English, French, German, Italian, Simplified Chinese, Spanish, Traditional Chinese

Age Rating


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

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