Beware of cheap underperforming clones

As of 2022 there are many badly performing clones on the market. V2/3GHz NanoVNA uses parts like ADF4350 and AD8342 which are costly and clones have been cutting costs by using salvaged or reject parts.

See official store and look for V2 Plus4/V2 Plus4 Pro versions only to avoid getting a bad clone. We have stopped selling V2.2 versions since October 2020, so all V2 hardware that are not Plus or Plus4 are not made by us and we can not guarantee performance.

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TDR COLORS #nanovna-saver

Phil, WF3W 2022/06/13 19:45

Good day, all,

Can someone, please, tell me what the *GREEN* trace and the BLACK trace represent on the TDR graph. WHERE on this graph is the length value of coax being measured?

Does anyone know why TDR always, severely, bungles the length value of my coax-under-test, e.g., a 54 foot length is given as 1.77 meters.?

Thanks to all 1st responders.

73 - if apropoe

Phil, *WF3W*

John Gord 2022/06/14 00:16

Though more recent firmware may vary, take a look at the following message to get some idea on how to set up for TDR:
The time (and length) range depends on how high the frequency range is set.  For long cables, use a lower maximum frequency.
You want a time range that goes up to 200ns or so to allow for the round trip time for a signal on a 54 foot cable; try a maximum frequency of 100MHz or so.
--John Gord

On Mon, Jun 13, 2022 at 10:32 PM, Phil, WF3W wrote:

Siegfried Jackstien 2022/06/14 21:54

how did you set up vf?? (velocity factor)??

as far as i know the value is to be set in "percent" .. means a cable
with vf=0.66 neds a setting of 66

dg9bfc sigi

Am 14.06.2022 um 04:45 schrieb Phil, WF3W:

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