There should be a few categories.
I'd propose:
- OpenGD77 CPS
- OpenGD77 Firmware
- OpenGD77 Hotspot
The Benefits of OpenGD77
The Benefits of OpenGD77
Perhaps we should start a thread of user experiences, and some of the benefits of using OpenGD77 technologies.
There should be a few categories.
I'd propose:
There should be a few categories.
I'd propose:
OpenGD77 Hotspot: Automatic Frequency Control
OpenGD77 Hotspot: Automatic Frequency Control
The center frequency of received transmissions is more critical on DMR modes than in analog FM. Handheld and mobile radios are often a few hundred cycles off center relative to the precision achieved on software defined radio hats.
When using some software defined radio hats like the common MMDVM simplex and duplex boards used in many "JumboSpot" products, the receiver is not implemented with automatic frequency control features active or effective. For this reason large BER bit error rates can be experienced, requiring setting of RXOffset and TXOffset. These settings are often different for different individual portable and mobile radios that connect to the hotspot.
While these settings remain available for configuration and use with the GD77 in OpenGD77 HS Hotspot mode, they are not necessary because the radio implements AFC.
The receiver in the GD77 AFC compensates for the small inaccuracies in radio oscillators, allowing better quality reception free of BER artifacts. This leads to better sounding audio. It's not necessary to configure a RXOffset or TXOffset when using OpenGD77 HS in Hotspot MMDVM mode.
The center frequency of received transmissions is more critical on DMR modes than in analog FM. Handheld and mobile radios are often a few hundred cycles off center relative to the precision achieved on software defined radio hats.
When using some software defined radio hats like the common MMDVM simplex and duplex boards used in many "JumboSpot" products, the receiver is not implemented with automatic frequency control features active or effective. For this reason large BER bit error rates can be experienced, requiring setting of RXOffset and TXOffset. These settings are often different for different individual portable and mobile radios that connect to the hotspot.
While these settings remain available for configuration and use with the GD77 in OpenGD77 HS Hotspot mode, they are not necessary because the radio implements AFC.
The receiver in the GD77 AFC compensates for the small inaccuracies in radio oscillators, allowing better quality reception free of BER artifacts. This leads to better sounding audio. It's not necessary to configure a RXOffset or TXOffset when using OpenGD77 HS in Hotspot MMDVM mode.
OpenGD77 Hotspot: Increased power
Within reason, a hotspot implemented using a GD77 radio running OpenGD77 HS Mode firmware can transmit at considerably higher power than a hotspot using a software defined radio hat like the JumboSpot, OpenSpot and others.
While the GD77 can transmit up to 5 watts DMR, it's important to consider that the radio was designed for portable handheld use, and it's heat dissipation characteristics will likely not tolerate full time use at full power. A DMR hotspot can spend considerably more time in Transmit if it's configured for multiple static talkgroups, any of which received from the voice over IP infrastructure (Brandmeister) will key the transmitter.
For event usage, lower power (I generally run mine at 1 Watt) and a better location, including better antenna system, will give considerably extended range using the GD77 as a hotspot.
While the GD77 can transmit up to 5 watts DMR, it's important to consider that the radio was designed for portable handheld use, and it's heat dissipation characteristics will likely not tolerate full time use at full power. A DMR hotspot can spend considerably more time in Transmit if it's configured for multiple static talkgroups, any of which received from the voice over IP infrastructure (Brandmeister) will key the transmitter.
For event usage, lower power (I generally run mine at 1 Watt) and a better location, including better antenna system, will give considerably extended range using the GD77 as a hotspot.
OpenGD77 CPS: Additional features
The OpenGD77 CPS when used with OpenGD77 Firmware in the radio offers considerably expanded features and configuration options.
Tools in the CPS are available for fast and reliable flashing of the GD77's firmware, welcome screen, welcome tune, radio calibration and loading the DMR to Call database for call lookup within the radio.
OpenGD77 CPS and Firmware allow more flexible configuration of multiple talkgroups on a single RF channel using a reduced number of channels, simplifying the kind of flexible usage that Hams prefer.
Tools in the CPS are available for fast and reliable flashing of the GD77's firmware, welcome screen, welcome tune, radio calibration and loading the DMR to Call database for call lookup within the radio.
OpenGD77 CPS and Firmware allow more flexible configuration of multiple talkgroups on a single RF channel using a reduced number of channels, simplifying the kind of flexible usage that Hams prefer.
Re: The Benefits of OpenGD77
For me one of the big benefits of OpenGD77 is it might demonstrate how a DMR radio should be designed for amateur radio use. Pick a repeater, then pick your talkgroup. That simple. This would solve a lot of the confusion about having to program N times for N talkgroups, or lack of channels, lack of space in zones, confusion about how to switch talk groups, etc.
Current functionality I think could use some spit and polish but it's quite functional. But the methodology of how one picks where they want to talk, IMO, should be a starting point every DMR radio should use from here out
Current functionality I think could use some spit and polish but it's quite functional. But the methodology of how one picks where they want to talk, IMO, should be a starting point every DMR radio should use from here out