PulseModem A


iOS APRS client that reads and reports APRS location and message.

Full AX.25 software AFSK modem for APRS


APRS is a digital communications protocol that can exchanges information among large number of stations both local and global.

You as a licensed Amateur Radio operators can send and receive APRS location and message in 2 ways:

  • Direct to the APRS-IS Network
  • Sent via amateur radios supporting VHF Band at 144MHz.

Core Functionalities

Faq

Frequently Asked Questions

What is PulseModem A?

PulseModem A is an APRS client, that reads and reports APRS location and message. The messages are relayed to the APRS-IS network.

APRS is a digital communications protocol that can exchanges information among large number of stations both local and global.

How do I send messages?

You can send directly via Internet, a.k.a. "TCP/IP" or by radio frequency.

You just need to connect your Amateur Radio with your iPhone with an audio cable. A built-in modem will convert your payload message to AX.25 encoded AFSK message, which will then be sent via your radio.

How do I receieve messages?

You just need to setup your Callsign SSID and APRS passcode, then you are connected to the APRS-IS feed. All station messages within 100km of your current position will be read.

A built-in AX.25 modem can also decode RF signal received from your radio. So you do not need Internet in this case!

Which frequency do I tune to for APRS operations?

It depends your area. Common frequnecy in North America is 144.390MHz wheras it is 144.640MHz in other areas.

You can scan 144.390 to 145.570MHz for APRS signal. It is a very identicable chirp which is less than 2 seconds in length.

How does PulseModem A determine my current position?

PulseModem uses the built-in GPS information provided by your iPhone and iPad.

Future versions may interface other standalone GPS units via BLE.

Is it open source?

PulseModem A is open source iOS app. In the spirit of amateur radio, the app has to be open sourced. It also leverages many open source technologies, too.

Please go to www.pulsemodem.com for more info.

Pulsely has been shipping iOS, Mac & Web apps since October 2008. 79 quality apps have already been shipped by the Pulsely Consulting with more than 3M total downloads from the iTunes AppStore