Thank you all who responded. You've been very helpful in helping get this figured out.
Regarding using SoundModem as a standalone Digipeater, I could not find the settings within that program to do that. So I considered that approach, but was unable to test. So N5TIM if you have more info on that, I'm curious to know how you did that.
After seeing everyone's messages and talking with the Winlink team about this on the phone, I decided upon a different approach. I setup RMS Packet on one machine and put it into "Digipeater" mode. In that mode, it automatically forwards received VHF traffic. I have tested it and confirmed that in that mode it works.
In the original scenario I described, the Sender needs to specify "Digipeater" as the P2P session type, enter the destination and then use my Digipeater's full address (including SSID) as the "VIa" address. So, like this:
THIS WORKS. No internet connection required.
Open the .ini file and enter your call with an SSID on this line.
MyDigiCall=
Would be good if a short youtube video can be made for newbies to encourage and show how to setup such combinations .
Often they are tried and due to limited knowledge or specific settings the idea is left for a rainy day that never returns .
Here are the step-by-step instructions:
Make sure Soundmodem is turned off.
Go to your UZ7HO Soundmodem folder
Right-click on the soundmodem.ini
Click Open with
Select Notepad (or Notepad ++ or similar)
Scroll down to the section labeled [AX25_A]
Find MyDigiCall=
Enter MyDigiCall=CALLSIGN-4, e.g. K6OLI-4 (in SoCal we have an informal standard to use -4 for field stations. You can use whatever you want.)
Click File > Save
Done.
You can now start your UZ7HO Soundmodem and it will act as a digipeater whenever it is running. It can act as a standalone digipeater, so you do no Winlink express for this.
It will work just as well with Winlink in connected mode and with APRS. Note: UZ7HO is a simple digipeater in APRS, so WIDEn-N is not supported (but it will respond to whatever is in the MyDigiCall field).
73 de Oliver K6OLI
Just wanted to add to what Oliver said. If you choose to configure Soundmodem this way as a digipeater. don't run RMS Packet in Digipeater mode. You'll find out quickly as I did that it will create an endless loop of transmissions if you do that!
I personally have not managed to get Soundmodem to work on its own as suggested. I tried. it just didn't work. I ended up removing the suggesting entry and running just the RMS Packet gateway in digipeater mode.
Regarding RMS Packet and Soundmodem with Winlink Express running at the same time: it doesn't work well. The two programs interfered with one another in my practice session. When I had one OR the other running, they worked fine with Soundmodem on their own.