Doing a bit of testing with my SX1255 board. Got a bit of an odd issue with modulation accuracy...
| Pronouns | he/him |
| Blog | https://foxdog.blog |
| Signal | Ret.10 |
| Discord | @retsplines |
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Half-fox, half-wolf, half-engineer. Into electronics, radio & software. (Very) amateur radio operator. Talk to me about TETRA V+D. Talks about NSFW stuff sometimes - please be 18+ 🔞 Runs (NSFW) https://isthisyiff.net
If I lower
TxDacGain right down, the drifting stops, but the modulation accuracy gets really poor (see RMS & Peak values here). That seems vastly preferable though...Basically, with TxDacGain set to anything other than the lowest value, I get very weird I/Q offsets introduced that shift the constellation and cause occasional demodulation errors.
Note that the modulation is actually quite accurate but with weird offsets (haven't actually got my brain around what this actually means in terms of the signal itself though yet - it's not a frequency/clock drift because that would be a rotation not a linear offset).
First time designing and testing an RF filter. Was aiming for knee at more like 450MHz but this is pretty good (I think).
Yeah, the experimental setup isn’t great… no SMA torque wrenches here…
