Video looking at the some experiments with a Tandem style SWR coupler. The coupler uses two FT50-37 toroid cores, each with 10T. Details at: zl2ctm.blogspo...
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@ae0ai3585 жыл бұрын
this is very cool! Interesting to see what a low frequency directional coupler looks like!
@CharlieMorrisZL2CTM5 жыл бұрын
Hi. I don't have 160m in the shack, but it seemed to work well using the sig gen. Charlie
@moustaphamuhammad70135 жыл бұрын
I love When it comes to the pigtail of coaxial cables terminals. And also your pin and paper explanation.good keep up the good work.
@CharlieMorrisZL2CTM5 жыл бұрын
Thanks Moustapha. Hopefully, the log amps will arrive soon and I can continue.
@moustaphamuhammad70135 жыл бұрын
Charlie Morris we'll be waiting for the latest 😀
@bundylovess5 жыл бұрын
Good progress mate its looking good big thumbs up 👍
@CharlieMorrisZL2CTM5 жыл бұрын
Thanks Allan. I'm debating about trying a log op amp again as I wait for the AD8307s to arrive. That or work on the SNA.
@32cdromcz2 жыл бұрын
tnx bravo since the libraries from you fit me to my arduin now only a mustek and and I can have you thank you
@christinamarks63495 жыл бұрын
Hi Charlie! Just a question/observation (because it wasn't clear in the video).... In almost every rendition I have seen with directional couplers, the forward and reflected sense ports, in this video going to the oscilloscope, are typically terminated with resistors (respectively) matching the transmission line impedance, the obviously most common being 50 ohms. I didn't know if your oscilloscope has input terminations and, other than the discussion about padding, you didn't mention it in the video. I would think that the lack of, in this case, 50 ohm terminations on the respective sense ports could impact your measurements. Again, just a question/observation. 73 :)
@CharlieMorrisZL2CTM5 жыл бұрын
Hi Christina. Yes, you are quite right. Both the FWD and REV ports do have 50 ohm terminations. You can see the 2 parallel 100 ohm resistors that I used for each port on the video banner picture. I also understand that these are important to minimize high voltages across the transformer windings.Charlie
@christinamarks63495 жыл бұрын
Yep. totally missed that! LOL!
@CharlieMorrisZL2CTM5 жыл бұрын
No worries Christina, I do it all the time. Apparently, I have 'boys eyes'... :o)
@watsok5 жыл бұрын
Great video as always. With many hams rig being 100 w, could you discuss the pad values needed at 150 watt?
@CharlieMorrisZL2CTM5 жыл бұрын
Hi Kenneth. I could, but the problem is I don't know what the FWD port will produce at 100W input. I'll see what i can do.
@angeldelvax72194 жыл бұрын
Looking at the coupler box; does it make a difference for the measurements on what side of the coax you connect the ground?
@CharlieMorrisZL2CTM4 жыл бұрын
Hi Ronald. I must admit I struggled a little with the same question. In the end I went with the configuration in the original article. If you have the time, try both options and see how it works.
@raafatalheety8265 жыл бұрын
Good morning The is box is very large
@CharlieMorrisZL2CTM5 жыл бұрын
Yes it is. Probably an overkill, but i did want to keep the transformers away from the sides (increase d-distance) to reduce capacitance.
@ashave91005 жыл бұрын
Hi Charlie -Thank you for the over my head video -Hi Hi !!! It will take me a week to try and unravel the maths !! Can I ask you- where do you find the 10 Log power numbers from ? (It is the only bit that stumps me) ! If it is not to much trouble(and your valuable time ), would it be possable to do a short run though the 10 Log power calculations on your next video please ? I am sure there must be someone else out there confused by them ! Thank you again -M
@CharlieMorrisZL2CTM5 жыл бұрын
Sure thing. I'll add that into the next video. In the mean time, this may be of help: en.wikipedia.org/wiki/DBm Charlie
@CharlieMorrisZL2CTM5 жыл бұрын
I'll aim to put up another short video tonight that looks specifically at the calculations. Hopefully, that will be of use.Charlie
@ashave91005 жыл бұрын
@@CharlieMorrisZL2CTM Hi Charlie-Thank You, that would be brilliant, I would then have a great reference point to work back though all of the sums you have completed since your very first video. Thank you again for you time and patience -M
@CharlieMorrisZL2CTM5 жыл бұрын
Gidday. I've just put up a video. No doubt there will be some errors, but hopefully, you will find it useful. Charlie