I’ve been fooling around with DMR for a few years now and figured it was time to build a DMR hot-spot. I had a few DMR radios on hand already. Some Motorola XPR handheld radios in both VHF and UHF trim and also a TYT MD-380 for 70cm. But what really pushed me to do this was my desire to experiment on the 33cm band and the availability of the Retevis RT10 which is a 33cm radio that does DMR. And the fact that many of the MMDVM boards support 33cm.<\/p>\n\n\n\n
First I acquired an RT10. Now I needed to make a DMR hot-spot. I learned that the Raspberry Pi 4B had issues with heat when coupled with an MMDVM hat and no fan so I picked up a Raspberry Pi 3B kit as the base for this project. With it’s lower clock speed and reduced heat output it was said to work good with a “hat” on it and no fan. Fans piss me off. The only noise in my ham shack should be coming from the speakers in my radios!<\/p>\n\n\n\n
Next I grabbed an MMDVM “hat” (from Amazon) that plugs into the Raspberry Pi ‘s GPIO header. I chose a duplex one with a display just to keep my options open. For the difference in price it seemed silly not to. The one I got had a TCXO (temperature controlled crystal oscillator) so that eliminated the need to tune the offsets. I got lucky in that regard but given what I know now I would never even consider getting an MMDVM that didn’t have a TCXO. <\/p>\n\n\n\n
For an operating environment I selected the WPSD software. It appeared to be the best choice at this time. <\/p>\n\n\n\n
It all went together quickly and easily. Because I was already familiar with DMR and all that it entails I had little trouble getting it all set up. I joined my hot-spot to the Brandmeister network for my initial testing and usage. There are others but Brandmeister looked like the big dog on the block and a good place to start.<\/p>\n\n\n\n
Experimentation with my DMR hot-spot continues. Once it was tested with the Retevis RT10 on 33cm I set it up for 70cm use with my old TYT MD-380, which also worked well. The MD-380 is a better radio that the RT10 in many ways but the point of my experiment was to use 33cm for something. And now I am.<\/p>\n\n\n\n
Talk group 91, the worldwide talk group on the Brandmeister network, is quite active and always entertaining. Perhaps we will cross paths there.<\/p>\n\n\n\n
Here’s a picture of the completed hot-spot in action:<\/p>\n\n\n\n
<\/p>\n\n\n\n I’ve been fooling around with DMR for a few years now and figured it was time to build a DMR hot-spot. I had a few DMR radios on hand already. Some Motorola XPR handheld radios in both VHF and UHF … Continue reading ![\"\"](\"https:\/\/ve6bc.radio\/wp-content\/uploads\/2024\/07\/hotspot-768x1024.jpg\")
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