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With Win7 you need to manually install the driver. See the Wiki in this group for details.. Roger

The overheating issue on my NanoVNA-H appeared early in April after I installed beta firmware titled "NanoVNA-H v0.8.3_96kHzIF_3.2kHz_sweep_points". Looking back I wonder if that firmware was a factor

@ Igor-m.... I used your settings and by setting the threshold up and down many many times I found my max threshold setting @ 305150000 and can leave it there for hours, it never gets unstable. The

Thanks for all the suggestions. I ordered an H4 and will experiment with an aluminum heat sink that bridges from the si5351 to the AIC 3204. The si5351 was never hot to the touch, so it does not take

Hello, I have a new H4 unit that I just got a couple of weeks back. Works great until I go to us it with a PC. What I am seeing is on win7 the laptop that I am using never sees anything when I plug in

My tests with threshold: In the latest H4 source the threshold is set 300.000.100 Hz. I set 201p, 1kHz BW, start=900M, stop=1000M I started to increase the threshold till the display shows mess. ch>

In nanovna.h i begin use AUDIO_CLOCK_REF (86016000U) Try revert to #define AUDIO_CLOCK_REF ( 8000000U) // 5ms @ 96kHz // Define aic3204 source clock frequency (for 8MHz used fractional multiplier, and

I built the latest H4 fw version (pulled from Dislord's github 1.5h back) with sdcard and 32kHz xtal. Soldered xtal and socket in, flashed the fw in (shows old fw version on the LCD). Set time (do not

It's important to note that this thread has 3 periods of comments that are somewhat out of sync. 1. My original comments that were ... well, whatever. 2. My recent reply to clarify that I did not

Did you try to change the threshold, e.g. the frequency at which the SI5351 switches to harmonics mode? All nanoVNA use the SI5351 way out of spec. Try threshold 250000000 first and calibrate till

1) use a frozen watermelon 2) drill vent-holes into the case 3) glue a small heat-sink on the top of the SI5351 chip 4) relax the SI5351's overclocking (lower its frequency) 5) increase the SI5351's

I as well would like info on buying one On Thu, Jul 16, 2020 at 6:20 PM, Darrell Carothers<rescuemedic1@...> wrote: That is correct. Darrell Sent from my over-rated IPhone 7 Plus.? Any

The results are in, it is the si5351. On the first attached sweep the chip was not cooled, the other sweeps were made while holding a frozen cotton swab against the chip for increasing amounts of

DiSlord took the thermal pictures, and I am guessing it is his NanoVNA-H4, which I am also guessing does not have a problem. I have a NanoVNA-H, not a NanoVNA-H4, and mine has a problem. I do not have

This may be why the VBAT is now enabled all the time...that would mean no diode startup time. That would mean a steady state current of maybe 30 to 36 uA over the battery discharge cycle. I wonder if

The ?T is 18°C; 13°C; and 15°C. Some of the cold spots are actually on the circuit board. The two closest to the IC packages may be holes for mounting. I would not consider the holes significant.

44degC at the packages is not too much, unless you do beefy overclocking :)

In this wiring the diode does not represent a source of "instability", imho, except its -2mV/K TC. The current via the diode is in, say, 35-40uA region (with 100k divider) and that is almost constant

Hot pictures! Looks like all three chips are candidates for a heat sink. I installed the old 0.8.4.5 firmware, then I put the NanoVNA in the freezer for a few minutes to see if I could make it through

Made thermal photo NanoVNA Heat si5351 (1.jpg) generator and LD01 DCDC (3.jpg) CPU (2.jpg)