Roger;
With Hugen¡¯s NanoVNA-H-AA installed, the output power of port 0 measures ~ -7 dBm up through 300 MHz. At 301 MHz it drops to -17 dBm and holds pretty tight to that up through 900 MHz.
The 900 MHz release version of eddy555¡¯s firmware yields ~ -14 dBm up through maybe 250 MHz or so, then drops off to around -20 dBm at 800 MHz.
I¡¯m certain that the only variability over power is that which results from the the available choices of drive current... I think there are 4, so there¡¯s not much wiggle room to warrant making that a feature on the earlier boards. I haven¡¯t attempted to follow the board upgrades to comment on those with any credibility. Once again though, the drive current leves also alters the source impedance of the si5351ports, and I don¡¯t recall seeing anything that might buffer or isolate impedance changes on any of the ports.
BTW... I use the console commands to pull raw data from the device. I didn¡¯t make the observation that the si5351 drive current can be modified within that utility. It doesn¡¯t seem it would be a useful adaptive parameter, but it would merit being a stored system configuration parameter.
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73
Gary, N3GO
