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Thanks everyone for the great advise. I especially like the screen shots (and experiments) Roger made (thanks Roger). For my purposes (looking at antenna reflections), re-calibrating looks to not be

Steven, For best accuracy you need to re-calibrate. This is especially true if you only have 101 data points since there will be more interpolation when you zoom. However if you are only interested in

Steven, the 6MHZ and its surroundings from the first production may be even more interesting when the value of the cooling condenser was inadequate. Read more on my web site. -- Gyula HA3HZ

For the standard nanovna, there's 101 points - so if you calibrate from 3-30 MHz, you have a cal point every 270 kHz.? When you zoom in, the software interpolates between those points. So over your

You wouldn't have to, but the number of points it is calibrated for would be less in the smaller range. It's best to re-calibrate and get the benefits of all the calibration points in the new range.

Hi all...am new to this group. Have a question about calibrating the NanoVNA. If I say calibrate from 3-30 Mhz...and then decide to look (or zoom in) at frequencies from say 5-6 Mhz...do I need to do

Indeed it was and it seems to be giving me good measurements now with the antenna I am testing. With an antenna tuner I can get an impedance of 32 ohms at 1620 KHz which is my desired frequency. On

Yes! That's the kind of thing I was trying to get you to find. That type of mechanical issue is almost always the problem when something that was working suddenly stops, especially after manipulating

I found the center conductor and dielectric and after putting them back in the VNA is responding correctly through out its full range. Sometimes a little poking around can solve a huge problem.

A classic problem is when someone "stretches" a piece of coax to make it reach (or when pulling through a conduit or around something else), and the center conductor pulls back within the shield,

A little embarrassing but I think I found the problem. I checked the SO-238 to BNC male adapter I was using and THE CENTER CONDUCTOR IS MISSING! It likely got lost on a piece of coax that I was using

The cable tests correctly at DC with a multimeter with the braids connected and the center conductors connected correctly. The setup I have is exactly the same as when it was working correctly but

When I have a problem like this, when something working suddenly stops, my first impression would be that a connection/cable has a problem. So I check each carefully. Sometimes a cable is broken right

I calibrated it for the upper edge of the AM band, 1600 to 1700 KHz and it worked really well before with the calibration done in this range. For some reason with calibration done in the same range it

What frequency range are you calibrated for? Perhaps recalibrate for a narrower range spanning the AM broadcast band, say 200 kHz to 2500 kHz.? Good luck. Ken - WB?OCV Show quoted text

What frequency range are you calibrated for? Perhaps recalibrate for a narrower range spanning the AM broadcast band, say 200 kHz to 2500 kHz.? Good luck. Ken - WB?OCV

Those creations will likely work adequately for HF frequencies and below. But at VHF and above, the leads and composition of the resistors will cause some issues due to the parasitic inductance.

I checked it elsewhere and it does not seem to be responding at all below 50 MHz so it is not just the AM broadcast band but also HF and to an extent low VHF as well.

try these out,, i too have been trying to get better cal kit just for the nanovna, i made set of so239 (see my post "Calibration, Compensation, DIY Parts Hacking!...... My First Post!") and i think

Thanks for a great reference, Roger. There's much to be learned in that video. 73, Ralph Bolt, K?RO