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/g/nanovna-users/topic/defective_nanovna/32747641?p=,,,20,0,0,0::recentpostdate%2Fsticky,,,20,2,0,32747641

My previous email should less-non-negatively been: not being specified to 300MHz does not prevent most Si5351's from being overclocked to 300MHz. Arguably, were the SA512 >>less<< nonlinear, second

Thanks I will study the YouTube video. If a DUT is a linear device then harmonic responses will just superpose linearly and I can see one can use DSP software to disentangle them. The SA512 is a non

Yes, the chips can be programmed directly at 300 MHz and actually beyond. When the chip runs out of range it will actually just sit on the previous called for frequency and ignore the command. The

Just because the Si5351 is not specified for 300MHz does not mean that most cannot be overclocked to generate 300MHz fundamentals. Michael Knitter uses the same Si5351 with a weaker processor in his

That is interesting. I have not played with SiLab chips for quite a while being more familiar with the Analog Devices AD98xx families. I couldn't? find in the data sheet if it can be programed

What is the scale of this plot? Is the 900MHz end 40dB RL. It can't? be less than 70dB anywhere if each y grid is 10dB.Sent from my Samsung Galaxy smartphone.

What causes the spike to show at 300 MHz when it switches and what has been done in the later software to get rid of the spike? Burt, K6OQK

What causes the spike to show at 300 MHz when it switches and what has been done in the later software to get rid of the spike? Burt, K6OQK

The nanoVNA begins using the second harmonic as soon as the sweep crosses the 300 MHz threshold and, at the same time, boosts the output level of the Si5351. It does this again at the 600 MHz

Think you may be confused in the way Marker | Center works. Marker | Center moves the center of the screen to the current Marker position not the other way around. It does not move the Marker. It

The Si5351 is rated to 200 MHz but most work to well over 300 MHz on the fundamental. There are other products out there, notably among them RFzero , that are based on the 5351 and produce usable

Wow, quick update Oristo. Lets hope none of the other builds aren't different! Mike

How does the nano do that when the Si5351 can only generate a square wave up to 200MHz? The schematic shows these signals just come straight? out? Digital Alias signals or something?Sent from my

Thanks Hugen, I ordered it. Thanks to the others too. I know I can use the NanoVna without it but I like using the switch mainly for moving the marker. Jim K.

Attached spectrum analyzer plot shows the output of the nanoVNA at three different CW stimulus settings: Red trace shows 250 MHz setting - Fundamental is used. Green trace shows 350 MHz setting -

https://lcsc.com/product-detail/Multi-Directional-Switches_Korean-Hroparts-Elec-K1-1502SA-01_C145915.html

Hi Mike - Based on my experiments, firmware uses (only) last selected marker to set START, STOP, CENTER, or CW. SPAN seemingly uses 2 markers...

Hi Mike - Thanks for feedback; content is updated: http://ormpoa.altervista.org/Hnano.htm

I did actually do that and was seeing about the same return loss. The plot is somewhat noisy and there is a periodic spike at perhaps 300 MHz as captured in the attached photo. Peter