D74A and XLX Special Character Woes

A fellow New Jersey ham was having the hardest time using my XLX reflector. He could connect to a reflector module. He could hear conversations, but none of his transmissions were making it out over the reflector. Strangely, he had no such problems when using a DPlus reflector. His radio is a Kenwood D74A.

He uses a SharkRF openSpot2 as his hotspot. While helping to search for a solution, I remembered a thread I saw on the Pi-Star Forums. The author complained of not being heard on an XLX reflector via a D74A. The cause and the solution had nothing to do with Pi-Star, but rather it proved to be a quirk with the D74A and the XLX software.

Apparently the D74A allows any character to be entered into the Callsign Extension field. These are the 4 bytes following the “/”. While these characters were orignally made available to support reciprocal operations and portable suffixes, they are now commonly used to identify the type of radio being used. So my D74A callsign is setup as K2IE____/D74A (the underscores represent spaces). My friend’s radio had “@?” in the Callsign Extension field. These unexpcted characters seemed to cause the XLX reflector to ignore the attempted transmission.

The Icom radios support only A-Z and 0-9 in the callsign extension field. The D74A allows lowercase and special symbols too. Don’t use anything other than A-Z and 0-9 in the Callsign and the Callsign Extension fields and you won’t have this problem.

To make things more interesting, the ham who reported this issue is visually impaired. He relies upon the radio’s voice prompts. However, the Kenwood D74A voice prompting system ignored the @? characters completely, so he never had any idea that they were present. Another local ham who was alerted to the special character problem on the D74A spotted the issue and fixed things.

73 de K2IE

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