We have a Pager that works, but no pager service is available. People have moved on to phones.
Amateur radio receivers

Features
- Incoming SMS
- Outgoing Landline
Electronic Engineering Technologies
Resources for Radio, Radar, RF, Microwave, & Wireless Engineering. Collection of links to various application notes for different RF Vendors. Links to RF equations, technical data sheets, math notes and much more.
Some important areas
E-flite Mini Pulse XT – Brushless ESC Waveform
This waveform shows the square waves that drives one of the three phases at a relatively low throttle setting (coming from the brushless speed controller). The peak amplitude is constant for all speeds.
“Much more than just a self-serving video of my new R/C airplane flight agility, this model represents a plethora of modern electronics. Although the radio control system in this plane is a standard narrow band FM variety on 72.170 MHz (as opposed to my 2.4 GHz, spread spectrum system), the motor is a state-of-the-art 3-phase brushless model (E-flite 450)with a sensorless electronic speed control (E-flite EFLA331, 20 A).”