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What about the cores in computer power supplies? What are those good for?

Thank you so much for this video. I havent thought about the resistance between each terminal for different Attenuation networks and i certainly didnt expect them to be all identical! I tried modeling a bridged T Attenuator on SimSmith but unfortunaly i cannot figure out how to do it, since with SimSmith you cannot add a bridging resistor with the sequential box scheme. I downloaded your files on drop box but i realize i need to actually read the manual. Anyway i am eternally greatfull for SimSmith to exist.

That is interesting, I'm glad I found this channel.

谢谢你。 你的视频全是我最需要有知识！！ 再次感谢你的知识传播！！

I have been investigating winding toroid inductors. I start with a T50-2 core from Amidon. 1 turn, 2, 3, 4, 5, 6, ... 15 turns of #24 insulated wire. I repeated the same experiment with a T50-6 core with very similar results. I am winding them at 100%. I am measuring the impedance using a Tektronix TTR503A VNA properly calibrated at the end of the clips where the toroid is connected. I consistently get more inductance than the equations from Amidon would tell me that I would have. This increase is generally on the order of what would be expected with 1 additional turn on the core. Based on this video here, it seems that this is not unusual and that the calculated inductance from the official formula is more of a minimum value than it is an actual expected value. Maybe you can help me understand this a bit. Thanks.

That's all well and good (sent me to sleep it did with the drone sounds, never mind the missus put it in pause before tapping me on the shoulder.. sleeping dear she said..?? Nah was listening I said (and then spotted hw much I had missed). Oh buggah well it hadn't woken me up with what I wanted to know.. So, how do I use a toroid then? I want a 1:1 audio toroid, to accept 20hz to 20 kilo hertz, at approx. 150 watts? Which toroid core should I buy and hiw much of what sized enamelled wire will I need?

Sendust? Are they same acros the industry?

Is it possible to make a speaker transformer out of one of these for 8 ohms for tube radio?

Great

I'm learning how to make SWPS for car audio...attempting real high power values. This is great info, and yes the fact that any medium has an effect on the reading is both surprising and expected. Audio has led me to concepts in physics and understanding the nature of light and waves, it's no surprise that at high frequency, there appears to be a sensitivity to matter.

did not get it, not yet, don't know what is inductance, flux, cores materials for 60hz or for 20 khz, nothing...

I am interested in building an impedance matching circuit for phasing two vertical antennas. Can you point me to any pod cast you or others may have done on multi winding impedance matching simulation using SimSmith? Thanks!

Why does flux density matter? Why impose a 100 flux limit?

Larry, thanks for this video. Did you notice the SWR values for the 80m band are different from LastZ.txt in EZNEC vs that same file pulled into SimSmith? Or, are my old tired eyes deceiving me? The EZNEC Swr/Pwr view shows just under 1.5 at the lowest point in the 80m band but the LastZ.txt file pulled into SimSmith shows over 2.0 at the same lowest point in the 80m band. JT, NO5X

I have some questions about RUSE blocks. If you build a passive LC filter in a RUSE block, can you define the Q of each capacitor, inductor and have them available/settable below the block like an individual component element filter? Can the power within, voltage across, and current through each RUSE block element be displayed outside the block like an individual component element filter?

Fantastic Series Larry. Thank you for your hard work and dedication.

Larry, can you explain what VNA, PC platform, and PC software you used to create the two .csv files for the 11 and 14 turn chokes? Where did you come up with RCM = 290 ohm and XCM = j600? Can you provide a link to Kevin Smith W9CF's paper on common mode impedance? Thank, JT

Really well done!

Hi. I find this stuff fascinating but conflicting. Maybe you can help me. There’s a guy on RUclips (Dazecars), who has a nice design for a variable speed controller for a 130 vdc treadmill motor using a SCR. After the SCR, he goes to a toroidal inductor to reduce noise (it’s still AC then). My question is 1. What type and size toroid do I use? 2. How many wraps for hot and common wires? 3. Does it matter if the wraps are equal spaced? 4. Does it matter how each wire starts it’s wrap? Above or under? Both the same etc.? I really appreciate your help here. Thanks, Paul

Hello Larry and thank you for what you do and all that you share. My question is not regarding simsith but I'm still hoping that you can offer your thoughts on this topic. My question is in regards to selectable autotransformers / unun. I am planning on running a random wire configuration with the MAT-40 tuner. At times I will be able to run 41' but on the trail that may decrease to 17.5'. So are the 4:1, 9:1 dual step or 4:1, 9:1 & 16:1 autotransformers worth the convenience or does having the selectability decrease the efficiency and effectiveness and is it best to have dedicated transformers? Thank you kindly Gary

Question for you. I'm interested in constructing a inverter for a old BC611 hand held. I need a 88mh toroid. Can you give me a rough idea of physical size of the core?

Thanks for the video. I’m operating at 100w so based on this I think I’m good even with a random wire antenna, but definitely with a correctly measured dipole. Have a 240-31 which I’m going to wrap with some RG316 and will just test myself it to make sure. Again, thanks for the video.

Larry, first off thanks for doing this video. I'm still trying to get the hang of all this. One thing that hangs me up about SimSmith, is (to me) the odd grouping of compartments LG1 & LG2; which have components grouped together that are actually from separate distinct circuits. Can you explain if the reason that the boxes encompass the components the way they do? Thank You Very Much & 73...

Oh please, I'm not looking for a software tutorial. I want a simple explanation of the physics involved in using circulators, isolators, a few phase shifting cables and the use of a few dummy loads. Good bye

How are we actullay importing the core materials characteristics into simsmith?

I find I learn the way you teach. I rewatch your videos as I need to remind myself of what I need to know. They are an easy to understand treasure trove of RF engineering knowledge, along with hints and observations that take years to learn on one's own, and you charge nothing for any and all of it. You're a true Elmer Thank you.

Great video, a lot of enthusiasm, thanks for sharing. On the "SimSmith" part of the video we see a clever solution to obtain the load impedance range given a matching network impedance range, Incredibly usefull when trying to get the components to build a real thing, which a lot of times is a headache for component searching. That will be fine, as you stated on the "Graphing" part of the video, for a single frequency but not for a frequency spweep due to the diferent increment that the reactive components have since WL is not equal to 1/WC.

I like the decision tree you made for choosing the crystals. I just got a bunch for cheap and need to do this, want to build an IF crystal ladder filter

Impedance is not so important in an absorber. Because these tores are in serie with what appear as an antenna in some case it can deteriorate the filtration that you try to achieve you need resistance.

Great video, thanks for sharing experience and knowledge. It helps a lot when you're trying to get into this components. If I'm allowed to make a suggestion/request... It will be great if you can explain the core materials, it's nomenclature, what they mean, what should we have into consideration when you say for example this is material 30

My kinda guy🤘

Thanks for your perfect explanation

It doesn't have a problem or a "dark side". It's a "Medical" Isolation Transformer, not a "Lab" Isolation Transformer. It's exactly how it's supposed to be. Obviously, it's easily converted but, to say it has a dark side is incorrect.

Sir i am making a DC DC Buck converter with input voltage of 120 v and output of 15v with 20 amps and frquency is 100khz for this i need to design a inductor so how to choose a core for this or can u suggest any core i can used for this application

GAMES TO PLAY...

Thanks Larry for this graphical explanation. 73... I do have a question: Since we have reflections coming back to the generator, can we consider the generator as an instantaneous short-circuit so that current is produced in the 50-Ohm generator source-resistor; like we do for DC-sources whereby their (ideal) internal resistance is considered to be zero? Retired now so trying to get back into RF which was my childhood initial interest; so trying to learn LTSpice and SimSmith while also building receivers and transmitters.

Great video! Thanks Larry!

Watching this again was a huge help. If you don't mind me asking, what's your background to have such knowledge on the subject? Thanks again for taking the time to make the video as it seems that you've done a ton of research on the subject.

Excellent video Larry. Always a cut above.

Two questions 1) SimSmith is up to version 18. A video updating the features of SimSmith would be helpful. Is it still worth while for someone to set up a Version 15 edition of SimSmith to complement a Version 18 edition? 2) The nanoVNA-H4 has addressed many of the short comings of the original nanoVNA. Does that warrant an update video for the nanoVNA?

tooo fast to comprehend

Again, very interesting. Enjoy the mountain biking.

Brilliant useful presentation. Lots of ideas

Hi Larry Two questions for you. The first regards the Fair-rite Data sheets for the ferrite cores. Under the Material Tab The first graph displays 2 Curves for Complex Permeability. One curve is labelled u' the second curve is u". I can't find a legend table that specifies what these curves are plotting. I want to determine what the performance difference is between 67 & 68 material in the application for a resistance transformer in the HF to VHF range. From the overall description it seems like u" is more significant and needs to stay as low as possible. The Application also is a critical factor. While material types of 67 & 68 are best for transformer applications at HF 43 material is needed for EMI Suppression in the same frequency range. How did they come up with that ? ? ? It's very confusing. AA6XE Bob

Thanks for the hints snd tips Larry. They are very helpful

This has been very instructional It would be very helpful to be able to see how to actually wire up the components in an antenna system according to the design in Sim Smith. So a video of you actually connecting a pine network onto an antenna or a stub match onto an antenna So far this is all been theoretical it would be nice to see the practical application of actually placing these components to see how they'll look

It's just dumb firmware. The VNA should have the ability to calibrate across a range of frequencies saving all the data during each step. Every time you fit a short an open or a load it should sample a range of frequencies, rather than it just taking one frequencies measurement at a time. With 3 calibrations it should be able to save the data for an entire range why don't they just update the VNA's to work this way?

Thanks Larry I just keep coming back to these SimSmith video's they always add to my insight.. 73

I'm wanting a VNA from 160M to at least 10M But i want to be able to attach it at the feedpoint 60ft up and then read what the antenna is saying in situ. I was looking for a vna with bluetooth so i could observe it from on the ground. I'm planning on using open wire 300 Ohm ribbon but can't find much info on using a vna with open wire. Wondering if the way to do it is to calculate a good coax length with the vna, then observe the antenna so it can be tuned with the tuned coax, then swap out the coax for open wire?

Du bist n Guter, das merkt man gleich! Stabil!