Santa Clara County ARES®/RACES
Home Services Operations Data Credentials Training & Events Reference About

Network Access using AX.25 over VHF Amateur Radio

Overview   |    Services   |    Connect   |    Equipment   |    Resources



AX.25 is a protocol based on the X.25 protocol and uses amateur radio call signs for addresses. It is efficient for low bandwidth, lossy environments, such as VHF/UHF radio. This makes it ideal for access to the packet BBS network from anywhere in Santa Clara County. The use of VHF radio means RF coverage throughout the county is good enough for most locations to reach at least two of the packet BBS systems.


Accessible Services

AX.25 over VHF Amateur Radio can be used to access the following SCCo ARES/RACES service:


How To Connect

User Access

BBS Forwarding


Equipment and Software



Application Notes

Configuration and Setup Instructions

  • Standard TNC Parameter Settings - 10/31/22 (PDF - 1.2 MB)
  • Setting Your TNC's Audio Drive Level
    • This is an excellent tutorial on FM deviation for packet, why it's important, and how to set it.
    • Skip to "The No-Test-Equipment Packet Adjustment System" for a method to set 1200 baud deviation by ear. The result will be very close to ideal.
    • If you have trouble hearing the difference between audio levels, you can use a simple audio dB meter located near the speaker, such as an app on your smartphone.

Technical Reference




Santa Clara County ARES/RACES Packet Training Classes
Covers everything from assembling and using an existing station up through building your own station and using advanced BBS features.


User Group

A discussion/e-mail group is available for SCCo ARES/RACES members interested in packet networking.

To Join: Visit our Discussion Groups page to learn how to subscribe to our main Announce group. Once approved, you can subscribe to the Packet group.


Technical Support

How to Request Packet Networking Technical Support


If you have Packet Information that you would like to have included here,
please contact the Webmaster, Phil Henderson

Web Site Home Page

This page was last updated 31-October-2022