CARA has a digipeater at the Prince Frederick site operating on 145.750 MHz with a callsign of K3CAL-1.   All are welcome to use this digipeater for packet communications as well as reaching Winlink gateways.
The digipeater can also be used to check the operation of your own packet station.  Just connect to yourself via K3CAL-1.  After connecting, anything you type should be echoed back to you.   The string to connect is shown below.  Just substitute your call for mycall.
C mycall v K3CAL-1

For more information, contact Shawn / N3AE.