Tuning Your Antenna Tuner using an Antenna Analyzer or VNA (007d)

[@jmcexx]

Excellent video. I really appreciate you taking the time to show the simultaneous videos of the tuner and analyzers while tuning.

[@eie_for_you]

Thank you! I thought it was quite cool to see how the controls of the tuner changed the way the trace looked on the VNA. 🙂

[@Knklhd77]

Keep putting out some very informative videos. I see your subscriptions are growing. It’s a slow process. But your short informed videos, will be popular. Thanks again.

[@eie_for_you]

Thank you! I keep trying. :-)

[@kirkjohnson8259]

This is an excellent explanation and demonstration. Most timely considering I just got an old HealthKit 1000w roller inductor antenna tuner. And I have been having trouble tuning with it. Going to connect my nano analyzer to it later to see if I can at least get a baseline on each band. Thank you sir Kd9rek 73

[@eie_for_you]

Thanks, man! I am glad that you found the video helpful. I'd be interested to hear how that works out for you. 🙂

[@buddyhoover57]

Excellent demo. I'm a very new ham and thoroughly enjoyed the explanation.

[@eie_for_you]

Thanks so much! I am so glad that this was helpful.🙂

[@AB1Vampire]

That's a rare Dentron. Thanks for posting

[@eie_for_you]

You're welcome! :-)

[@donaldsmith3048]

I have a MFJ 949E. I think it would tune like that last one you did. It doesn't have a band switch, or rotating inductor, but has a inductor selector. Thank you for the information! I wished I had that tuner. But it may take up all the room I have for all my equipment. 73

[@eie_for_you]

You are very welcome! It was a fun video to make. 🙂

[@larrypicard5969]

In my experience, adding a Smith Chart curve (on the VNA) greatly simplifies the process. Adjusting the Smith Chart curve so that the closest point on that chart is nearest prime zero at the frequency of interest shortens the process of reaching an optimal match.

[@eie_for_you]

I can see where the Smith Chart approach would be very helpful. Unfortunately, most people's eyes kinda glaze over when faced with a Smith Chart, partially because they do not fully understand it. The SWR view is something most everyone understands. For an even more definitive view of the tuning point, the Return Loss format would be ideal.

[@SpinStar1956]

Great Video Ralph! I was wondering about the VNA calibration-plane. Did you just calibrate at the VNA or did you calibrate at the antenna tuner to zero out the coax that would normally go to the Xmtr? Also, I have built a 1:1 balun (that is to be used for a friend's amateur radio club for their Winter FD) and have been able to successfully test for SWR and RL (using a SAA2-N VNA) but I wanted to do a supposed 'common-mode' test whereby you configure as a S21 measurement. In this setup, the VNA shield is continuous (between S11 & S21 ports; but has NO connection whatsoever to the balun) but the S11 center-conductor is connected to the center-conductor of the input SO-239 (through a series-resistor) and that same S11 center-conductor is also connected through another series-resistor on the SO-239 back-shell. Then on the S21 side, its center-conductor is also connected (also through a resistor) to one of the balun's output legs and again, the S21 center conductor is also connected to the other output leg through another resistor. The problem is that when I try to duplicate this experiment, I just get really weird results (RL looks somewhat believable but SWR is in the hundreds!). I also don't know exactly what the value of these resistors should be and if there is any 'calibration-plane' involved and where it lies. In short, I have no feel for the measurement or any confidence in any data. Is there any way to contact you (if your willing) so that I could email you this setup and additional ancillary information? Thanks & 73...

[@eie_for_you]

I can identify! I have not done a lot of this. I did find this article helpful, however. www.kn5l.net/Balun-CM/BalunMeasure/ Port 1 is connected to the balun's input side...both center conductor and ground. The ground of port 1 is connected to the ground of port two. Now, on the balanced side of the balun (this article assumes a 1:1 balun), there is a 25 Ohm resistor between balanced side A and port two's center conductor and another 25 Ohm resistor between balanced side B and port two's center conductor. This gives the proper balanced termination for a 1:1 balun. Calibration would be performed at the end of the cables as close to where you would be making the measurement as possible. The S11 calibration plane is at the end of the cable connected to port 1 where you performed the VNA "Enhanced Response" calibration. "Enhanced response" will calibrate for both S11 and S21 measurements; so, open, short, load, thru and isolation. I think with the nano VNA, this is what they consider a full two-port calibration (S11 and thru). I can be contacted via ARRL. I also have a Facebook account by the same name as this channel. Hope this helps! 🙂

[@eie_for_you]

This all has piqued my own interest. I think it deserves a video. I do not know when I will get to it. I have several videos in queue at the moment. But, I have added it to the queue. It'll be fun! 🙂

[@SpinStar1956]

@@eie_for_you first off, thank you very much for responding and researching my comment. I will definitely look into the article you sent and very much appreciate you, including that! I think this would make a very good video as there is great ambiguity, about not only the method, but the theory behind this measurement. I have seen this measurement made by other, KZbinrs, however, when contacted, they do not respond to specific questions regarding how they came up with certain values, or seemingly mystical correction factors that they just gloss-over or assume to be common knowledge. Thanks again Ralph I really appreciate it! 73 …

[@eie_for_you]

@@SpinStar1956 You are very welcome! 🙂

[@boxingday11]

Thanks 👍🇬🇧

[@eie_for_you]

You are welcome! It was a fun project for me.

[@victoryfirst2878]

How would I be able to check my Free To The Air antenna VHF UHF for TV Sir ???

[@eie_for_you]

I am assuming you are talking a 300 Ohm system. A VNA assumes a 50 Ohm. Let me ping a friend of mine and see what he says.

[@victoryfirst2878]

@@eie_for_you 300 ohm to 75 ohm balun. Thanks for your help fella.

[@eie_for_you]

Yes, understood. If we assume a 300 Ohm to 75 Ohm balun is in play, then the VNA or antenna analyzer is still expecting to see a 50 Ohm impedance and will report its findings accordingly. So, let's talk an entire system which will include your antenna (300 Ohm) through your 4:1 BALUN (==> 75 Ohm). The antenna analyzer or VNA will be "seeing" 75 Ohms when this system is in perfect tune. This represents a 1.5:1 SWR. I did, indeed, ping my friend about this situation and will report back as soo as I hear back from him.

[@eie_for_you]

Well, my guy didn't reply, so I did some research. If you are using something like a nanoVNA or miniVNA tiny to make the measurements, then you simply calibrate the VNA with a 75 Ohm load (assuming you are looking out at the antenna through your 4:1 balun). If you are trying to use an antenna analyzer, you are stuck with the whole 50 Ohm thing. :-( A perfect SWR would be 1.5:1. Most of what I found had to do with 75 Ohm, not as far out as 300 Ohms. In the end, the VNA calibrates out all of the reflections and other errors as part of its calibration process. My guess is that, even at 300 Ohms, you might be able to calibrate with a 300 Ohm dummy load and make your SWR measurements; the reported SWR should be right. Some inaccuracies are going to be introduced, but the whole process of tuning an antenna is not a terrifically precise process, so these should not affect the outcome in any significant way. Everything I do lives in the 50 Ohm world, so this is somewhat new territory for me. I'd be **really** interested in what comes out of this.

[@victoryfirst2878]

@@eie_for_you Thanks for giving me information that I asked for Sir. I will keep you in the loop no matter what the outcome will be Sir. I have found one learns more about anything when the outliers are investigated and figured out. Now the fun begins for me fella. Good day and peace too. vf

[@bigdaadio.K2WW]

You had 2 different setting on the tuner using analyzer and VNA or was I looking at it wrong?

[@eie_for_you]

The SWR curve is actually pretty broad. So, it is not inconceivable to have different settings putting you somewhere within this relatively broad dip. Furthermore, there is the difference in accuracy between the antenna analyzer and the VNA. 🙂

[@bigdaadio.K2WW]

@@eie_for_you Great Videos Thanks for taking the time to help new ies and old-timers alike! Not many of us left, no more in sight!

[@eie_for_you]

@@bigdaadio.K2WW True that! I'm no spring chicken myself. I just *have* to share what I know and what I am learning (or re-learning) while I still have a brain to do it. There *is* going to come a time when I cannot. You are very welcome. It is my pleasure! 🙂