About Us

Critical RF Direct was started in October 2009 by Critical RF, Inc. Founder Steve Calabrese


Steve, with his associates Alex Norwood and Dr. Sam Gray, unexpectedly ignited the PTToIP revolution in 2001 at Clemson University by designing and pioneering the Critical RF software and hardware suite.


It turned out what would become the Critical RF Worldwide PTT for Smartphones, Computers, and 2-way radio systems was the first ever working PTToIP platform that allowed people and companies with mobile devices, computers, and 2 way radios to instatly talk worldwide.


Patents were filed with the USPTO and WIPO and granted soon thereafter.


CriticalRFDirect.com is committed to the very best in customer service.


Our references are vast, worldwide, and available to you upon request.


We look forward to helping you design the most efficient and cost effective system for your needs.


Gradatim Ferociter,


The CriticalRFDirect.com team




Steve Calabrese


Founder - Critical RF, Inc.


President - CriticalRFDirect.com


P. Mobile (803) 474-4745


P. Email: CalabreseSteve4@gmail.com






Partners and Brands

We have teamed up with following radio and remote manufacturers in order to serve you better when designing and interfacing Critical RF systems.


We currently work with the following manufacturing partners to provide tested accessories:

  • Motorola, Inc.
  • Raytheon JPS Communications (ACU1000, SNV12, NXU-2(a), ACU-M)
  • Telex-Vega signaling products (DSP223, IP223, CSOFT)


We offer the following brands at our store:

  • Critical RF - Unified Communications.


If you have an equipment design or interfacing questions please contact us and a Critical RF Direct system engineer will be standing by to assist.