Відео

Aaah, so someone copied from the A.R.R.L. (or did they copy from someone else?). Isn't it *FUN* to play with antenna designs?! 🙂

Well ... it isn't recommended, but, I suppose, in a pinch, if it is carefully and thoughtfully performed, it *might* be possible. It is pretty tipsy until the guys are in place. I have a 20 foot mast made of steel pipe that I put up by myself. The guys are already attached and premeasured. Pushing the mast up and against the guys as I sweep the base along the ground, I get the job done alone. With that said, it is a LOT easier ... and **safer** with two. 🙂

You're right. I've passed the supporting rope through a pulley and down to a 40 pound weight. As the tree blows in the wind, the weight goes up and down and the tension on the antenna remains the same. This saved my antenna a lot of grief. 🙂

Yup, they are a great design! ... and inexpensive, too! I've seen the eye bolt used, too. 🙂

Thanks! 🙂

😲

You aren't the only one. I hear it all the time with folks who are so "quick on the switch" that the courtesy tone doesn't even get a chance to do its thing. Admittedly, it's hard to remember to leave that space. 🙂

I'm glad you found it helpful! Welcome aboard! 🙂

I cannot answer that question with confidence. Sorry. :-)

You are most welcome! 🙂

Our God (the One and Only) is an awesome God! :-)

I've seen that kind of setup in the more recent handbooks. In those illustrations, they show the feet of the ladder sitting in a hole that they dug for it. :-)

Thank you very much!:-)

That's something! The problem with the average rope is stretching and degradation due to ultraviolet light. Eons ago I used the real heavy gauge, galvanized steel electric fence wire (like 12 AWG). A regular, real tower ... not such a good idea. You will see why when my next video comes out. 🙂

@@eie_for_you Polyester and nylon are sunlight resistant, especially polyester. (those pants from the '70's will never break down!) On another note, I did knowingly make some contacts while my antenna was on the ground after an ice storm and it performed rather well! Of course a matching unit was involved. They should have a contest like field day where the whole point is to have the most dysfunctional antenna that can still make contacts. Can be a lot of fun and teach about antenna physics (physics is phun)! Take care!

The funny thing is, I bought a 500 ft roll that's been unopened in my attic since 2012! The open wire works so well, I haven't bothered to replace it. Lil' Abner would be proud of my ant. :) 73!

@@W1RMD I can see it now ... rope woven out of a whole bunch of disco suits that you bought from the thrift store! LOL 😀

@@eie_for_you I meant to say LMR-400 above. I have an unopened 500 foot spool of it! The ladder line works so well on every band 80-10 meters, I just can't see replacing it. Some heavier gauge wire and better spacers to make the ladder line would be a great start. I don't know if 600 ohm would be electrically better feed line, but it would be more robust mechanically and less likely to short against itself.

Hi

Sometimes that is sooo true! 🙂

I can see your point, especially when made with 2x2s. I made mine with 2x4s, so that didn't end up being an issue for me. 🙂

It sure is. My first exposure to it was with a 1940 handbook! 😲

Suggestion: When using synthetic guy rope, use four to six foot of metal guy at the ground anchor point. It eliminates problems that one could have with chewing animals, minor grass fires, and string trimmer accidents.

I've never used anything but wire rope or metal wire for guy wires. I'm still a wire rope kinda guy (pun intended). For something like this with as many guys as it has on it, we are not talking very big stuff, for sure. Interesting thought about this synthetic stuff. 🙂

@@eie_for_you A friend who is a commercial tower climber introduced me to synthetic line. Apparently that's what they use on a lot of commercial broadcast tower installations these days. Ever since then that's what I have used for tower installations. The end is terminated just like a commercial wire rope would be, a eyelet type "dead end". Think of a piece of wire rope folded over to form a eyelet and then each end is twisted around like a barber pole. The inside diameter of that twisted barber pole is coated with a grit material. It is wrapped around the synthetic rope end (actually the same thing has been used with wire rope guy lines for a few decades) and that's it, no clamps needed.

@@mikesradiorepair Cool! 🙂

This a great idea you have resurrected from arrl. I wonder if a vertical wire run along the upper part would work too?

Merry Christmas to you and yours, too! 73 🙂

There sure is! You can find the download links here: nanorfe.com/nanovna-v2-software.html The basic capabilities of the nanoVNA remain the same, there is some degree of expansion to how they are used with these programs and the user interface is entirely different. Merry Christmas! 🙂

@@eie_for_you Thanks!

Thanks Vic! 73 and Merry Christmas to you and yours! 🙂

I very carefully placed electrical tape where the trace and any other copper needed to be, leaving all the rest exposed. I then etched it using Ammonium Persulfate. NOTE: This stuff likes to be *real* warm in order to work. I had to have my etching container on a heating pad (for my back) turned up to high to make it work. 🙂

You are very welcome! 🙂

It depends entirely on what you are trying to do, actually. Like receiving CW (Morse Code), you want a very narrow bandwidth so that adjacent signals do not interfere with what you are trying to receive. On the other hand, listening to an A.M. signal, you want much wider bandwidth because the signal is wider. Notice, too, that the difference is the height of the resonance, not the width of the base. 🙂

Yes, I most likely would have done it the same way you describe in you comment for this simple example. But this would not have demonstrated the whole conductances in parallel simply add together. This principle is really important when dealing with complex impedances. 🙂

The one thing that folks forget to include is the 'j'. Z=R+Xj and j*j=-1. If you do not include this in your calculations, then ... 🙂

@@eie_for_you The reason your formulas at 9:16 and 9:31 are wrong is very simple. It is known that the parallel combination of two impedances are ALWAYS less than the smaller of the two. According to your formulas the parallel resistance is GREATER than the series resistance and the parallel reactance is GREATER than the series reactance. This is not possible.

@@Jnglfvr I am now sitting here looking at my A.R.R.L. Handbook for Radio Communication, 2008 edition, page 4.45. Here on this page you will see in formulas (102) and (103) the exact same formulas that you see on the screen on my video at 9:16 and 9:31. Remember, these are used to convert the Series R+jX circuit into its parallel equivalent circuit. They are not the equations used to calculate the resulting impedance of two impedances in parallel. I hope this helps to clear this up. 🙂

@ well then I’m not sure what is meant by “equivalent parallel impedance” do you? If the impedances are different then so are the currents. So in what way, exactly, are they “equivalent?”

@@Jnglfvr If I have an impedance of, say, 3 + j8, this implies a 3 ohm resistance in series with an inductor whose reactance is 8 Ohms at a particular frequency. So, what if I want to represent this same impedance in terms of a resistance in parallel with some reactive component instead. The overall impedance would be the same. It just happens to be made up of two parallel entities instead of two series entities. These equations allow you to calculate the values of these new entities. Hope this helps. 🙂

The point of all of my videos is not just the "how to" but the "why" behind it all. I appreciate your point of view on this ... and, yes, I can see your point. However, the point of my channel is for those who want to know more, understand the why, be able to extrapolate past the "how-to" to their own application. This requires more information which I provide. 🙂

@ You certainly do 😀

@@russc788 Thanks! 🙂

I am so very glad that this was so helpful. Thank you for letting me know! 🙂

I would not apply any more than 250 mW to the input either AC (e.g. RF) or D.C.(3.5 V) 🙂

You are welcome! 🙂

Thanks, man! I'm glad this was a help! 🙂

You are very welcome! 🙂

There is nothing special about the loads for the nanoVNA except the connector (SMA). I'm assuming that you are wanting something other than SMA connector. The trick is NOT to look for "calibration standards" but to look for 50 Ohm R.F. terminations. Be mindful of the "accuracy" or they might specify this in terms of maximum SWR. Inexpensive ones will run about $30'ish. Good one's a lot more. On the other hand ... you could build your own if you are not to concerned with absolute precision. You can put 2 x 100 Ohm or 4 x 200 Ohm, 0.1%, size 1206, surface mount resistors in parallel. Then very carefully solder them into a connector being very, very careful to keep the lead lengths as short and massive as possible. Not great, but adequate for a number of applications. Hope this helps. 🙂

Thanks! And it was fun to do, too! 🙂

Really good question! The big difference between very expensive, lab quality shorts and opens and the kind that are "good enough" for our use is certain aspects of construction and calibration (measurements of delays and the like). For what we do, you can take a connector, remove its center pin and you have an open "standard." The short standard is a bit more of a challenge. I used braid (coax shield or pieces of solderwick) to make the most massive short between the center pin and the body of the connector that I could possibly make. For what the average guy does, this would work just fine. Hope this helps. 🙂

@@eie_for_you Ralph, Yes its does thanks for the explanation I do have the SMA standards for the VNA, but no N-type or PL type standards. Looking on Ebay and other places the price of lab quality standards can get pricey so making my own is my best option as of right now.

@@U812-k7j Yeah, lab quality standards are ridiculous. You could use your nanoVNA using a port extension to evaluate your resulting standards. Cal with the SMA standards, add adapters to bring you to where you can connect your homemade standards, do the port extension, then connect your standards and see how they look. As a note ... in the professional R.F. world, the SO-239 is referred to as a "UHF female" and the PL-259 is referred to as a "UHF male." Knowing this will help you find stuff on the more professional sites. 🙂

🙂

Thank you so much, man! May God bless you and your family as well. 🙂