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some Nano VNA SAVER 40m antenna graphs

Barry K3EUI Member Profile All Messages By This Member #33809 Getting Ready for the new ** MidAtlantic 40m NBEMS net ** testing: Saturday and Sunday 10 AM EDT on 7068 kHz (vfo) coverage over a 300 mile radius from Philadelphia THOR 22 check in THOR 56 traffic (new alpha mode: w1hkj.com/alpha) Hope to have the net begin by October 7/8 2023 Need 5-8 net control ops from the MidAtlantic region I now have three 40m antennas to compare prop paths 1) Traditional Inv V dipole, center fed with 1:1 BALUN 66 ft 2) Full one-wave horizontal loop (140 ft) 3) 34 ft alum tubing Vertical (lashed to a tall tree) with two above gnd 30 ft radials and matching coil at base (like an inverted T ) I had to mess a bit with the length of vertical to get it resonant where I wanted it. de k3eui barry Aug 22 2023 40 m Vertical 2 radials above gnd TUNER.jpg 40m loop antenna 4 graphs.jpg 40m Dipole Center Fed July 25 2023.jpg
DougVL All Messages By This Member #33810 That will be a very interesting comparison test! I hope you publish all the details and measurements. (Great choices of antennas, too. My full-wave horizontal loop is terrific.) -- Doug, K8RFT
Barry K3EUI Member Profile All Messages By This Member #33828 What I found reassuring is that the four graphs (on all three antennas) all agree with each other! The RETURN LOSS (dB) is sharp (yes, I plot it as a negative value) showing the reflections are least (greatest return loss) where the SWR is lowest, and where the PHASE graph crosses ZERO degrees, and also where the Smith Chart is closest to the Bull’s Eye. Now “matching” makes more sense to me. Any one graph predicts the others. I passed all of these ham radio tests (teenager) without really understaning any of these graphs. Now (I think) I understand the relationships. the Nano VNA forced me to really learn what these concepts are all about. TU VNA SAVER author de k3eui barry
W0LEV All Messages By This Member #33830 Excellent work, Barry. I've always contended introduction of the NANOVNAs would be an outstanding tool for learning. You've proved that. The universities ought to be buying these in the 100s to teach what you have learned. Dave - W?LEV toggle quoted message Show quoted text On Thu, Aug 24, 2023 at 12:37?PM Barry K3EUI <k3euibarry@...> wrote: What I found reassuring is that the four graphs (on all three antennas) all agree with each other! The RETURN LOSS (dB) is sharp (yes, I plot it as a negative value) showing the reflections are least (greatest return loss) where the SWR is lowest, and where the PHASE graph crosses ZERO degrees, and also where the Smith Chart is closest to the Bull’s Eye. Now “matching” makes more sense to me. Any one graph predicts the others. I passed all of these ham radio tests (teenager) without really understaning any of these graphs. Now (I think) I understand the relationships. the Nano VNA forced me to really learn what these concepts are all about. TU VNA SAVER author de k3eui barry -- Dave - W?LEV -- Dave - W?LEV
Jim Lux All Messages By This Member #33831 On 8/24/23 8:09 AM, W0LEV wrote: Excellent work, Barry. I've always contended introduction of the NANOVNAs would be an outstanding tool for learning. You've proved that. The universities ought to be buying these in the 100s to teach what you have learned. Dave - W?LEV The universities are buying these by the dozen. Prof Ashwin Iyer at University of Alberta used them in a "intro class" along with a VOM (ECE 478) a bunch of parts and modules, etc. Even a soldering iron. During COVID isolation. They had a great experience. Might be behind a paywall A. K. Iyer, B. P. Smyth, M. Semple and C. Barker, "Going Remote: Teaching Microwave Engineering in the Age of the Global Pandemic and Beyond," in IEEE Microwave Magazine, vol. 22, no. 11, pp. 64-77, Nov. 2021, doi: 10.1109/MMM.2021.3102649. They did a great job. They had multiple resources, TAs who could explain on a one-to-one basis, etc. If you want to pursue more info, Prof Iyer would probably be happy to talk to you. Prof. Ashwin K. Iyer <iyer@...>
W0LEV All Messages By This Member #33832 Thanks, Jim. As you have likely gathered by now from my (too many) posts, in retirement I'm into promoting the hard sciences and math to the HS bunch and helping others learn the finer points of all things RF. Yes, I will contact Dr. Iyer. Thank you so much for the reference! Dave - W?LEV toggle quoted message Show quoted text On Thu, Aug 24, 2023 at 4:39?PM Jim Lux <jimlux@...> wrote: On 8/24/23 8:09 AM, W0LEV wrote: Excellent work, Barry. I've always contended introduction of the NANOVNAs would be an outstanding tool for learning. You've proved that. The universities ought to be buying these in the 100s to teach what you have learned. Dave - W?LEV The universities are buying these by the dozen. Prof Ashwin Iyer at University of Alberta used them in a "intro class" along with a VOM (ECE 478) a bunch of parts and modules, etc. Even a soldering iron. During COVID isolation. They had a great experience. Might be behind a paywall A. K. Iyer, B. P. Smyth, M. Semple and C. Barker, "Going Remote: Teaching Microwave Engineering in the Age of the Global Pandemic and Beyond," in IEEE Microwave Magazine, vol. 22, no. 11, pp. 64-77, Nov. 2021, doi: 10.1109/MMM.2021.3102649. They did a great job. They had multiple resources, TAs who could explain on a one-to-one basis, etc. If you want to pursue more info, Prof Iyer would probably be happy to talk to you. Prof. Ashwin K. Iyer <iyer@...> -- Dave - W?LEV -- Dave - W?LEV

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