On Sat, Nov 16, 2019 at 11:23 AM, hwalker wrote:
On Wed, Nov 13, 2019 at 07:16 AM, Larry Rothman wrote:
"There is an interesting discussion on hugen79's NanoVNA Issues page on
Github
regarding circuit changes/mods to reduce overall noise levels."
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Larry,
Hugen posted a chart a few hours ago showing the results of a new PCB with
some of the recent improvements installed (see attachment). S11 looks to be
<= 40 dB to 1500 MHz and S21 dynamic range is >= 50 dB to 1500 MHz.
- Herb
This image shows uncalibrated data and is used only to show that the resistance bridge on the optimized pcb still works well up to 1.3G. But because the 5th harmonic will be small, the sa612a itself produces harmonics, and the calibrated effective dynamic is still only 20dB.
