i was disappointed with my G90 ... sent it back after a couple days ... for $450 I expected more... the NanoVNA are excellent. very useful tools for sure.
Picked one up at Gigaparts and a few sma to so-239 adapters. Works really well for my basic needs of checking antennas. I just could justify the 400+ for many of the popular ham antenna analyzers out there on the market. Thanks everyone for the links above cause I'll investigate more on what additional things I can do with it.
Josh, Nice job with your video of the Nano-VNA. I just purchased one from Amazon. I am a professional RF/Microwave Electrical Engineer and have been using Lab grade VNA's since the 1970's. It is amazing what they can get into that little unit HW and firmware. One comment on your video, when you were doing the Calibration for the open, you left the sma connector open. This is OK, but that sma calibration item you did not use, you called it an thru in you earlier description is actually a calibrated shielded open. When you do the open cal you should place that item on the sma connector. It reduces stray fields at the open sma connector due to fringing capacitance. At these HF frequencies it is not a big deal, at microwave freqs it matters. Greg WA1JXR
Got mine from Amazon today, and I can say is the latest hardware revision up today. Has the battery diode and the resistors 41 and 42 in the latest hugen79 rev 3.3 schematics. Ports are shielded, comes in a plastic box that keep the dust out and with the complete calibration , sma cables and usb-c cables (usb-c to usb-c and usb to usb-c) has a triangular pluck for the touch screen. Recommended.
Thanks for that. I initialy thought to use that connector, but looking online it seems there are quiet a few people who say it makes no difference. Especially at HF frequencies. I assume moving up to the 900 MHz limit it would be more important?
How well does this work at 1.8 MHz? A weakness of the MFJ analyzers is the low signal level - so that when you hook it to a full-size low-band antenna (160M especially), AM broadcast signals (and other noise too, probably) over-ride the analyzer's signal, making it difficult or impossible to get meaningful readings.
The output level is 80 mVrms on mine. I don't know how that compares to MFJ. I tried it on my antenna in vertical only configuration and didn't see a problem. But I haven't tried it yet in the inverted L 160m configuration to see what happens with the 50 kW (daytime) BCB station about 10 miles away. My guess is that there will be some effect since the VNA range goes down to 50 kHz and there is no built-in BCB filter. (One could always make or buy one and add it inline if needed)
Being on the lower end of the financial scale, there are certain items I have not gotten yet, Antenna analyzers are some of them. This VNA is now solidly on my list of things to get. Even if a ham is letting another unit collect dust, I expect they will keep it as a backup. I replaced a faucet, still kept the broken one, in case I need a faucet outdoors for the dogs, one I can control from inside the utility room. How much did the F model cost. I have U/VHF and HF radios, and close neighbors on medical equipment, so I need to be aware of my RF "shadow" over the neighborhood.
The F model is about $120. The smaller screen units are about half that. I’ve seen a post discussing someone's firmware for the smaller ones that displays a huge font of SWR so it’s readable despite the tiny screen outdoors. (Being older I thought I needed the bigger screen generally). I suppose one could buy a second VNA and dedicate it as an analyzer. If you’re not going to do electronic projects and only need an antenna analyzer, you might be better off just getting a used one (like an MFJ or early model RigExpert) for about the same price since they’re designed for the task, easier to operate, and rugged.
This is one of the sites Ive been using for my H, hadnt seen this one until a few minutes ago. https://www.eham.net/forum/index Ive already tried it at 60' and even these old eyes have no problem but the sun is also down low this time of the year in NH so its easy to have my back to it. I find the size convenient and fits in most pockets without fear of damage. Sure a big step above the 259B Ive had since the late 80's. Ill likely get a F for the bench soon once it gets some more circulation and updates, the extended frequency range over the little one is a big plus here for my UHF/low microwave use. Carl Ham since 1955 Gear from 472 kHz to 2304 MHz
Yeah, the only antenna analyzer I've ever owned is a an Autek VA1, which has been acceptable for on HF for many years but is WAY past retirement age. I've used RigExpert but was always put off by the price and I really don't need a rugged special purpose unit since I'm not doing it frequently or on a tower, etc. So the NanoVNA was an inexpensive way to get both a hobby grade VNA and a portable antenna analyzer, even if it takes a bit of extra time to use it for that. I didn't realize before I bought the F model that it has a different processor than the others. Right now the only concern I've got is that the firmware is incompatible with the rest of the units and what that means for the future. There are at least three people who are actively writing for the Q and H models and a big community involved as well, whereas it appears that only one person (the originator) writes for the F at the current time, and there is a much smaller community. The last release for it seems to have been a month ago at least. It's not clear to me at the moment if the firmware is open source or not which I think for a project like this is critical. On the other hand, there must be plenty of people like me (and you) who want the larger display, so I'm hoping that a lot more people start working with the F model and all this gets worked out.
It doesn't need to be continually calibrated. Don't need such special care as most seem to say for ham frequencies. $40 from US shipper on eBay. It IS fragile however and I will put mine in a box with PL259 connector.
The NanoVNA unit will interpolate calibration data if needed. There are always 101 points measured per sweep. So the distance in Hz between calibration points depends on the sweep span at calibration time. If calibrating over the full sweep of 900 (H, Q models) or 1000 MHz (F model), each point is spaced approximately 9 or 10 MHz. If the span is then reduced to say 30 MHz, the unit interpolates the calibration data from only 3 points over the 101 points on that reduced span, which is probably not enough (though in looking casually I haven't seen a huge problem with doing this on my particular unit). So when making large changes in span, a new calibration is recommended, or recalling an appropriate one from memory. For smaller span changes it probably makes little difference because there are enough calibration points to use for interpolation. However one place where the calibration could vary dramatically is between the regions below and above 300 MHz. This is because above 300 MHz the unit uses harmonics of the driving signal, not the fundamental. Calibrations and other settings can be stored in one of five memories and recalled easily. The power on calibration is recalled from memory 0, so it's a good idea to store the full span calibration there. By storing frequently used spans and their calibrations one shouldn't need to repeat the calibration procedure very frequently.
The real power of the nanovna is realized when you connect to a computer and use software to control the thing. Then you can have as many datapoints as you require for a given sweep range, cursors and plots you can read, along with all the data you can ever imagine.
