Thanks to Kenny (K2ZZ) for adding TG31340 to his Hoboken (448.275 CC3) and Elizabeth (449.925 CC3) repeaters. This definitely fills in some holes in our mobile coverage for the DMR ops. You’ll find us on Timeslot 2.
From my home location in Aberdeen (Northern Monmouth County), I have HT coverage from indoors on the 2nd floor. So give it a try and be sure to send your thanks to K2ZZ if you run into him on the air. This is a nice addition to our network capabilities.
In an effort to prevent hijacking of DMR IDs by unauthorized users, the USA Brandmeister team is rolling out Hotspot Security as a requirement. This will begin on November 30, 2020…but don’t wait. It will take a few minutes of reading and effort on your part to get it setup, but the entire DMR community benefits by restricting the network to authorized users only.
Hotspot Security establishes as password that all of your hotspots will use to logon to the Brandmeister DMR Master Server. This is different from the password that you use to logon to Brandmeister Self Care.
They’ve put together an excellent explanation of how to setup this up on the OpenSpot, Pi-Star and BlueDV platforms.
A comprehensive introduction to DMR is available to hams at no cost, thanks to the efforts of John Burningham <W2XAB>. His “Amateur Radio Guide to Digital Mobile Radio” won the 2016 Technical Achievement Award at Dayton Hamvention and the second edition was published in 2019. Even if you think you know how DMR works, this guide is full of useful information.
If your view of DMR is limited to the perspective of Pi-Star and Brandmeister or TGIF, this free book tells the rest of the story in its 27 pages. It is an easy read and will enhance your DMR knowledge.
Last August, I presented a solution for the “lost transmission” syndrome when using an MMDVM duplex hotspot. Several members of the 020 Digital Multiprotocol Group and I remain dissatisfied with our overall user experience. Granted, fewer transmissions are being lost than at first, but overall the number of transmissions during a longer QSO that fail to properly negotiate with the hotspot are higher than we’d like.
Earlier this week, 020 member Scott <KB2EAR> did some further digging and came up with aditional ideas found on the interwebs. I’ve taken these recommendations, added some others, and tested extensively. Here is my new set of recommendations for MMDVM duplex hotspot reliability when using DMR. This supersedes my article from August 29, 2019.
1) Update to the latest firmware.
2) Run the MMDVMcal procedure to minimize the BER
3) Set the MMDVMHost modem TXDelay=50
4) Set the MMDVMHost modem DMRTXLevel=55
5) Set the MMDVMHost DMR TXHang = 20
6) Turn off any mode other than DMR to avoid protocol scanning negotiation
I withdraw my earlier recommendation to reduce the DMR preamble. After much consideration, it seems to be unnecessary, with no clear benefit.
So far, using these setting on 2 different N5BOC duplex hotspots have yielded excellent results and reliability. Negotiation failures are now the rare exception. Tests were conducted with an Alinco DJ-MD5, a TYT MD-380, a CS-700 and a Hytera PD-365. Give these settings a try and let me know how they work for you.
You may know it as CNJHAM, because that is how it all started. CNJHAM was first implemented as a lone StarNet smart group. CNJHAM then begat XLX020. Hardware transcoding was soon implemented and followed by links to Brandmeister DMR and YSF Fusion. In this new year, we’ve added Wires-X (for connection from Fusion repeaters) as well as P25 connections.
CNJHAM/XLX020A can be reached via the following methods:
If you’re a fan of either D-Star or DMR, you have probably noticed the proliferation of multi-protocol gateways. These gateways, such as the XLX020 system, permit users of radios of one type to communication with users of radios of another type. Multiprotocol gateways help to defragement the amateur digital landscape.
However, there can be issues if the transmitting operator is not registered on both systems. Have you been on a DMR radio and seen the transmitting party display as radio id 0? They are a D-Star (or Fusion or P25 or NXDN) operator who has not registered a DMR radio number.
For DMR operators who have not registered with their nearest D-Star gateway, transmissions could even fail to pass through the D-Star gateway to connected D-Star repeaters.
Therefore, k2ie.net highly recommends that all amateurs using any digtial voice mode register for BOTH a DMR radio id and with a local D-Star gateway, whether or not you have a corresponding digital radio.
I’ve spent a couple of months chasing down this issue, reading post after article on this subject. The consensus so far has been:
1) Update to the latest firmware. 2) Run the MMDVMcal procedure to minimize the BER. 3) Set the DMR preamble time on your radio to 960 ms.
After weeks of poor results, I came upon the solution that has worked for me (and for others) in a manual for the Anytone 878 produced by Bridgecom. Bridgecom recommends a DMR preamble duration of 100 ms.
1) Update to the latest firmware. 2) Run the MMDVMcal procedure (or enter the sticker offset values for RXOffset and TXOffset). 3) Set the DMR preamble to 100 ms.
Well, I was testing on an Alinco MD-DJ5, a radio very similar to the Anytone 878. So I tried the preamble setting (called Wake Head Period in my software).
I have now achieved the mystical “five 9s” of reliability. I press PTT, I talk, my transmission gets received.
Ah, the sweet smell of success… And kudos to Bridgecom for the level of support that provide for Anytone 878 users.
This solution has worked so far with an Alinco DJ-MD5, a Motorola XPR, and a CS-700 (where I had to use 120 ms because the dropdown increments in steps of 60.). Oddly, my Hytera PD-365 does not support values lower than 360.
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 changes. 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 Module A
64002 Private Call - Switch to Module B
64003 Private Call - Switch to Module C
64004 Private Call - Switch to Module D
64005 Private Call - Switch to Channel E
64006 Private Call - Switch to Channel F
64026 Private Call - Switch to Module Z
65000 Private Call - Query Status
68020 Private Call - Connect to XLX Reflector 020
XLX020A XLX020D is the gateway to the CNJHAM/TG31340 bridge.
XLX020C XLX020A is the gateway to the REF020A/TG31675 bridge.