Finally got me a VNA (noobie)

Hi all, absolute noob here, I have 3 Tbeams on the slow boat from China, after weeks of rummaging around I realised I need to learn how Antennas work and how to make and tune them, I purchases a Nano VNA, got it today and have been applying all the knowledge I learnt and feeling my way around the device.

I was able to do a test and it was pretty accurate, please note the Load cap is 51 ohms I don’t don’t know if that will affect the quality of tuning

I am using the time to learn how to use the VNA until the TBeams get here.

I am open to pointers and suggestions, I will also be making a few antennas and posting them here

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In your NanoVNA it looks like you are measuring a coaxial cable and not an antenna.
Maybe I’m wrong but I think you have to calibrate your VNA for the frequency between 300MHz to 500Mhz. otherwise it marks wrong values

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Have a watch of this video on how to use VNAs.

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I did very informative video

I calibrate it everytime I power it on, and yes it is accurate did some checks with that little dipole earlier. Bang on the money

The rtlsdr dipole antenna has a 100K resistor to bleed off static. It is not made for transmitting and could damage your output stage if you connect it to your board.

And you should calibrate every time you change frequency… not just on power up.

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What if I remove the resistor? Also I never planned to use this as an antenna, my initial plan was to use to to practice with the VNA, also removed the pols made some 1090mhz (ADSB) antennas from wire… I was amazed how we’ll it worked.

Do you have any recommendations antenna types?

Yes removing the resistor will make it safe to TX.

I would short the center pin to discharge static if you use it with your SDR without the resistor.

Antenna recommendations thread.

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After a few days and making a few different types and learning how to tune them, made this for adsb

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I will be attempting to make a 433mhz Jpole, will post the results here.

I think this will be my first version, took me a few hours, but finally got it dialed

I welcome any feedback, I will figuring a way how to encase it, maybe in a 1/2 inch PVC pipe.

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