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

You Say Protocol, I Say Reflector…

Is XLX a protocol? Is it a type of reflector? Why are we asking these questions?

There is a bit of a debate going on now in D-Star circles as to how the end user (you OM or YL) of a hotspot or repeater should connect to an XLX reflector. I’ve exchanged emails with some notable folks in amateur radio software development circles (Luc LX1IQ, Andy MW0MWZ, and Tom N7TAE) on the subject. The software developers are all in agreement. XLX is not a protocol, it is a type of reflector. On that point, they are quite correct.

To varying extents, each have indicated that the preferred way to access a reflector is via the protocol, node and module notation. Using this paradigm, to access XLX020A via DExtra protocol, you’d connect to XRF020A. But there could be an XRF020A that is not XLX020A. We’ll get to that in a couple of paragraphs.

On the other hand, Jonathan Naylor (G4KLX) has implemented the ability for ircDDBGateway to access XLX reflectors by name. Since all XLX reflectors support DCS protocol and DCS is the most modern of the three D-Star reflector protocols, ircddbgateway defaults to DCS connections. This make perfect sense to me. And it works!

Note: In case you did not know, ircDDBGateway is part of the software suite that comprises the exceedingly popular Pi-Star distribution. May of the tools provided as part of Pi-Star were developed by G4KLX.

As an end user of a hotspot or repeater, I just want to connect. There is also the problem of amgibuity. You can have an REF123, an XRF123, a DCS123, and an XLX123. They may or may not be the same destination. But XLX123 is a specific destination, as are the other three. So the best way to connect to an XLX reflector for the end user would be to allow the end user to specify that destination.

To continue to require that XLX connection requests specify a particular protocol, when there is no specific reason to do so, would be as confusing as requiring the end user of a mobile phone to specify what network the called party is connected to. Yes, the option is there, but let’s make this simple.

I’d like to see the various hotspot platforms adopt this aproach. What do you think?

73 de K2DLS


XLX Support Updates

There are a couple of big announcements to make in terms of support for the XLX reflector world this week.

The first development is that Kenwood has released firmware version 1.09 for the popular D74A handheld transceiver. Among the improvements contained in this release is direct support for selecting XLX reflectors by name on the “Link to Reflector” menu.

The second development is that Andy Tayor <MW0MWZ>, developer of the extremely popular Pi-Star hotspot software distribution for the Raspberry Pi, has made a change that allows the radio operator to directly select an XLX reflector. Previously, you would have to make a local host table override entry for an XRF or DCS reflector in order to make this work.

06-28 Alert: After some more testing, it seems that the Pi-Star change to allow connection via the XLX name isn’t working properly. Testers experienced one way audio with the initiator of the connection not hearing the remote end.

07-11 Update: XLX Linking is now working, with some tweaks to the ircddbgateway config. See this thread on the Pi-Star Forum for more info.

XLX reflectors just got a whole lot better thanks to these updates!

73 de K2DLS

N5BOC Duplex Hotspot

I managed to get my hands on one of the hot items in the MMDVM world — an N5BOC Duplex Hotspot. This is really a mini-repeater which uses both timeslots on DMR and has a separate transmit and receive antenna connector. Initial results have been as expected — excellent!

My idea was to have a hotspot where I could configure XLX on TS1 and Brandmeister on TS2. With the N5BOC board and Pi-Star this was a breeze. The key is in the DMR Gateway configuration.

My XLX configuration:

[XLX Network]
Startup=020
Enabled=1
File=/usr/local/etc/XLXHosts.txt
Port=62030
Password=passw0rd
ReloadTime=60
Slot=1
TG=6
Base=64000
Relink=60
Debug=0
Id=1234567
UserControl=1
Module=A

My Brandmeister configuration:

[DMR Network 1]
Enabled=1
Address=107.191.99.14
Port=62031
TGRewrite0=2,9,2,9,1
PCRewrite0=2,94000,2,4000,1001
TypeRewrite0=2,9990,2,9990
SrcRewrite0=2,4000,2,9,1001
PassAllPC=2
PassAllTG=2
Password="passw0rd"
Debug=0
Name=BM_United_States_3101
Id=123456701

If you’re not currently using DMRGateway, make sure that you have activated it by setting the DMR Master on the configuration page to DMR Gateway. This will reveal options to help you manage Brandmeister, DMR+, and XLX, all on the same hotspot.

Pi-Star Configuration for XLX020

Some simple changes must be made to the configuration of a Pi-Star based hotspot before it can access an XLX Reflector. Thanks to our partner in the “020 Project”, Scott <KB2EAR>, who helped with following guidance.

To connect to XLX020 via DMR you must configure your Pi-Star hotspot to use DMRGateway. Before you begin, make sure you hit the update button on the Pi-Star menu.

If you have not yet enabled DMRGateway, you will find the DMR Configuration looking something like this:


To enable DMRGateway change DMR Master to DMRGateway (very top entry).

Click apply changes and wait for the menu to come back up. Next change XLX Master to XLX_020. XLX Startup Module will usually be either A (Central New Jersey) or C (Beyond New Jersey, including REF020A & Peanut users). Turn on the XLX Master Enable slider.

Click apply changed. Once the configuration above has been applied you should be ready to go. Next, program the radio.

To talk via DMR on an XLX reflector, you’ll need to use a channel programmed with TG 6. Also set up a receive group list with TG6 so you will receive signals from the hotspot.

If you want to move your hotspot between reflectors and modules, commands are sent via a private call. These should be entered into your digital contact list.

6 Group Call - Talk on the XLX Reflector
64000 Private Call - Disconnect Channel
64001 Private Call - Switch to Channel A
64002 Private Call - Switch to Channel B
64003 Private Call - Switch to Channel C
64004 Private Call - Switch to Channel D
64005 Private Call - Switch to Channel E
64006 Private Call - Switch to Channel F
65000 Private Call - Query Status
68020 Private Call - Connect to XLX Reflector 020

XLX020A is the gateway to the CNJHAM/XRF020A/REF020D network.

XLX020C is the gateway to the Peanut/XRF020C/REF020A network.

See you in 020 land.

73