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I have not taken enough 1 port data between the two to state their measurement delta if any. As far as I can tell, the white unit is no different electrically other than the firmware, 2 track display vs. 4 track. Hence the pixel size array on the 4 track firmware vs. 2 track is somewhat finer. My colleague and I are going to update the firmware in the white one so 2 channels are engaged; S11 and S21. Currently, I think I will do some 1 port measurements, the worse (best) test case is measure a 1 dB pad shorted to provide a 2 dB return loss and compare their 1 port responses. That stresses the Gamma value and puts it out at 0.86 reflection coefficient.
________________________________ From: [email protected] <[email protected]> on behalf of Greg Ashley <Gregory@...> Sent: Tuesday, July 9, 2019 10:51 AM To: [email protected] Subject: Re: [nanovna-users] New nanoVNA received Is this black one, better than the white one? If so, do you have a link to buy it off the ebay ? -----Original Message----- From: [email protected] <[email protected]> On Behalf Of alan victor via Groups.Io Sent: 08 July 2019 19:16 To: [email protected] Subject: [nanovna-users] New nanoVNA received Just received my 2nd nanoVNA. This is the black case, no Gecko white which works current to date quite well with 2 track display. This black case arrived ON TIME and well packed. Apparently held it's charge all the way through shipment and booted with a 4 track display. These instruments are little like a box of cracker jacks or is it chocolate, your not quite sure what's in the box. So far, so good. This unit came in its own plastic protective case with all the accessories enclosed. The construction looks very good and robust. The ON-OFF slide switch and USB-C connector are more robust. There is a screen protector film over the display and no scratches on the display from a stylus being used on the soft screen for pretest. The style of the 50 ohm load is DIFFERENT. The short and open appear the same as with prior cal kit. Is this 50 ohm termination superior? Don't know. The prior was ~ 18 dB best case at 900 MHz. Very important, IT IS CLEAR THAT THE ASSEMBLY OF THIS UNIT HAS THE RF SHIELDS OVER THE BRIDGE AREA AND MIXER AREA AS SUGGESTED IN THE EARLIER POST. ALSO, THESE SHIELDS LOOK LIKE DIE CUT BRASS WITH PRECISION FIT. THESE WERE NOT CUT OUT WITH TIN SNIPS OR A SCISSOR AND HAND SOLDERED IN. THIS LOOKS LIKE A PRO JOB. Hurrah! There is a green film strip sticking out of the left side of the display. Looks like the kinda of thing you would pull to engage the battery contacts on a new toy to protect the battery during shipment. However, I have not touched it and the unit turns on out of the box. The display has the 4 color traces and the pixel appearance is smaller and crisper than the white gecko unit. So I will wait for a charge cycle to complete and see how this one plays. Hope this info is of assistance. Alan |
