HL2 without SDR software and directly on AK4951 COMPANION BOARD, possible?

Pete dong

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Apr 16, 2024, 11:22:27 PM4/16/24

to Hermes-Lite

Hi group

as we have AK4951 COMPANION BOARD which give HL2 direct link to mic and phones. will HL2 run without SDR software(PC side)? only use SDR software if you want to change the frequency and settings.

any thoughts on this, just trying make HL2 as simple as possible without raspberrypi controller etc.

BTW, any idea what is power consumption for HL2 receiver only mode

Pete

Steve Haynal

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Apr 16, 2024, 11:29:19 PM4/16/24

to Hermes-Lite

Hi Pete,

The HL2 does not do demodulation or modulation even if mic and phones jack appears on the unit. A host running SDR software is required. This is a common misconception. The AK4951 companion board is just an expensive ethernet sound card. All microphone data is sent to the host software for modulation. All demodulated data goes from the HL2 to the host software for demodulation and then back to the HL2 if you have a AK4951 companion card. Spend your money on a better and more generic sound card. Search this group for more details.

https://groups.google.com/g/hermes-lite/search?q=ak4951

73,

Steve

kf7o

Clifford Heath

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Apr 16, 2024, 11:32:13 PM4/16/24

to Pete dong, Hermes-Lite

The HL2 radio signal paths shares Ethernet with the audio paths added by the AK4951, but otherwise there is no connection between the two. All audio processing happens in the host computer.

It would be possible to write a transceiver app into the Cyclone IV gateware, but I don't know of any work in that direction.

Clifford Heath

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Heath Petty

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Apr 16, 2024, 11:34:09 PM4/16/24

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Even with the HL2+ board, the HL2 is not a complete radio. The HL2+ board is just a network attached sound card. I/Q packets are still sent from the HL2 to the computer, where software demodulates them. In the case of the HL2+ board, the demodulated audio is just sent back over the network to the HL2. A computer is still needed for all operations with the HL2.

From my testing, the RX power drain with the receiver active is not very much. I'll have to see if it even registers on my power meter, but if I'd guess its less than 500mA.