JOTA 2022 and DMR

  1. Some Lessons for next Year
  2. Multiple TG's in an RX-Groups
  3. NA on the Dashboard

I attended the Brisbane Amateur Radio Club's 2022 Jamboree On The Air (JOTA) occasion on the 15th October 2022.

Left to Right: Shannon VK4FHEA, Michael VK4MGO, Doug VK3DMB, Glenn VK4PK

This is Station 3 for Digital Radios. We used the VKDMR Network Server.

We had over eighty young people in attednace. Parade time.


Some Lessons for next Year

Here are a few lessons for next year for DMR. Handhelds cannot be heard over a dozen chattering young people. Plug in mic/speakers are even worse. Use a Mobile width a louder speaker. You need a strategy to handle User Activated Talk Groups with Hold and Demand Timeouts of 5 seconds.
Once you have the Time Slot, do not let the PPT up for more than 5 seconds unless the other party has theirs down!
To do this successfully it is essential to watch the Dashboard. Otherwise, the kids can be talking to nobody as both station have time out the UA.

Can multiple HH/operators work? Could connecting each to different repeaters. RBA, RMC, Hotspots solve this?.

Michael, VK4MGO did a great job entertaining the kids while I struggled with the technology. It worked better when we left the mob on the other side of the table and had a chair set up for the young operator on our side of the table.



Our biggest issue was to do with the JOTA operator calling on TG 30 and then moving to a 31 through 39 Talk Group. The Hold and Demand timer will holding the Repeater on the initial TG30 and even through the operator has moved. Trying to use TG31 through TG39 while the Hold and Demandtimer is still counting down is not possible.

The purpose of the Hold and Demand timer is to stops other operators "stealing" the TG from a group while they are undertaking a QSO. AT the same time allowing that group of repeaters to be freed up for other TG usage once the QSO is completed.

Setting the duration for these timers is a judgement, and this is an issue for some of the JOTA Stations. Short timers that apear to be about 5 seconds for the JOTA TG's take carefull management especially when handing to young people who are unskilled operators.


Multiple TG's in an RX-Groups

DO not have multiple TG's in the RX groups programed into the radio. for example if you have TG 30 to 39 set in a RX Group you will hear all TG 30 to 39 but when you PTT you will only transmit on TG 30. This will lwead to confusion.


NA on the Dashboard

NA indicates Non Assigned on the International Table but for Local use it is set as per the local requirements on the IPSC2 system.

Glenn Lyons VK4PK
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