Poor performance with DIY antennas

From where to download, and how to install latest firmware?

NanoVNA firmware

Please note that there are several versions of firmware for the NanoVNA out there, each with its own peculiarities. I would suggest before you try to upgrade the firmware, first read the wiki and other docs on group dedicated to the NanoVNA over here
https://groups.io/g/nanovna-users

There is also great PC open-source software available over here. Also discussed in the IO.groups.

NanoVNA saver. PC software

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@hellhound604
Thanks a lot for providing very useful links :+1:

One more question: when I search online, there are a large number of models & sellers. If you have purchased it or know a good model/seller, can you please proved a link to it? Thanks.

@abcd567,

I purchased mine from this seller back in August 2019:

The reason I went with it was that, at the time, it was one of the few that clearly showed/stated the additional screen shielding considered a worthwhile ‘upgrade’ by the ‘experts’.

As you saw, there are lots of options out there. Almost impossible to discern the good from the bad, unless one buys from the developer or cloner site directly.

I know you likely want the one that goes up to 1.5 GHz. It was not, and is still not, a requirement for me. After reading about all the checks one has to do before updating the firmware, due to the many different implementations, I decided to keep mine ‘standard’.

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Speaking of performance boost, I’m seeing the biggest one in a long time. What did I do? I disconnected my second ADS-B station.

Background: I used to have 3 stations in my garage. They were at least 3 feet apart from each other. As I was losing interest in additional ADS-B ‘work’, and wanted to re-deploy the RPis, I offlined one station last year. I remember seeing a change at the time, but nothing major, so I forgot all about it.

I offlined the second one yesterday. The change was even more noticeable this time around.

It’s still very early to say for sure, but looks like there was some interaction between them.

The uptrend yesterday which can be seen on your remaining receiver is not unusual for a friday, or?

I have a similar increase as well for that day without changing anything. You might need to monitor this for at least a week.
You have also an uptrend on # of messages, but in your history you had these improvements also (e.g. 02/14)

Your station above, mine below:

After running each antenna for 24h, the whip still wins by a large margin:

whip (area covered 80kkm2, max range 275km)


coax spider (area covered 50kkm2, max range 247km)

cantenna (area covered 58kkm2, max range 253km)

I’m getting slightly annoyed by this so I decided to bite the bullet and ordered nanovna-h4 :slight_smile: it should be with me in a few weeks.

Assuming I’ve built the antennas properly, the only other difference I can see is the coax. The whip is on magnetic base with 2m of RG58, while for the DIYs I’ve used RG6 but much shorter lenght, would that make such a huge difference?

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see this link re rg58 vs rg6 for ads-b applications
https://www.rtl-sdr.com/how-coax-cable-loss-affects-ads-b-reception/

For the price of the nanovna you could simply buy an optimized FA antenna.
I have no idea what issues your setup nas.

At the beginning i was the simple whip antenna, then i built a spider made from a simple coax with arms in correct length. I did not use any electronic device, however it outperformed the whip by at least 30%

Now i am using an optimized antenna i got from ebay for low price - done.

I could, but where would be the fun in that?:slight_smile:
I’m not after highest feeder ranking, I’m doing this for fun and to learn something.

Exactly! I was expecting at least some improvement but got even less. I want to find out why.

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Some antennas pick out-of-band signals stronger than other antenns, and therefore pick more TV and Cell Phone signals, causing overload of dongle and poorer performance.

Have you run a frequency scan for each antenna? The guide to scan is here:

Do I Need A Filter?

 

 

I didn’t, but the blue FA stick already has 1090MHz filter. I have a FM bandstop as well, I might try that.

EDIT: I’m running the scan
EDIT2:
the whip


cantenna

Your mag base does not use RG58
If assembled correctly, quality RG6 is significantly better than RG58 at microwave frequencies.

Awaiting results with your NanoVNA with interest.

 

Right. It uses RG174, which is single shielded.

 

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That’s what you did not write so far :wink:

Which is even worse at 1GHz than RG58

It does:


(I was positively surprised)

But it still doesn’t explain why the whip performs better:)

I’m rebuilding SO239 spider using crimp terminals instead of soldering. I had to really crank up the iron last time so maybe the head damaged the connector.

Theres a lot of ways to build them using less expensive bits, I ruined a few SO239 connectors trying to make pretty solder joints. :wink:

Here’s one I made using a simple F coupler connector, simply winding the ground plane radials onto it and tightening the nut. Simple, works fine doesnt really need to be soldered but I sweated the two pieces together.

Another I made using a copper plumbing pipe cap, drill four holes at the upper edge to solder the radials into and a center hole to insert an sma to F pigtail through it. Copper of course takes solder well. BTW, I did experiment some with the height of the ground plane on the connector and it didn’t seem especially sensitive to that.

My Spiders

4-legged

4-legged

8-legged

 

Nature’s Spiders

All 8-legged

spider 8 legs -1 spider 8 legs -2 spider 8 legs -3 spider 8 legs -4

Arachnovations ? :smiley: