JP1QEC, Mot invented a variabe wire length antenna, namely PT-antenna.The following video explains the novel antenna suitable for portable operations with his permission. JG1GPY Takeshi Abe.
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A Very Good Concept. Well Constructed. Thank You for the Video. 73de Paul M0CQE.
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Nice video Takashi I have Mr Mot’s version of the SOFT which is not wind up but is made with links for different bands. We had many QSO’s when Mot was busy on SOTA. It is always good to chase you on SOTA and I hope to hear you again soon on the air with this antenna.
Regards
Ian vk5cz …
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Thank you for the comment, Paul-san!
Ian-san, Mot is busy for stagazing recently, but still doing SOTA occasionally. He is invening gadgets for astronomy as well; he is always very innovative!
BTW I thank you for chasing me all the time. If you hear my signal better, my throwing skill is improved. Stay tuned! Thanks and 73 JG1GPY Takeshi
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Dear Takeshi,
Do you have details (photos) of the wire winding system for this antenna?
73’s
Laurent F8CZI
Laurent:
Let me ask Mot about your request if he has any relevant information, for you.
There is no special trick in the winding part according to Mot. The wodden part prevents wire from touching the metallic shaft in the middle. I hope it helps. Takeshi JG1GPY
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Dear Takeshi,
Thank you very much for the picture. It will help to avoid reinventing hot water 
.
Below a picture of the antenna I use for my sota activations, which is of a similar type.
73’s
Laurent F8CZI
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Dear Laurent:
Thank you for sharing the photo. I suppose the white-yellow container is the wire spool right? I am glad to know antenna of the similar concept is used in the different continent! I will tell Mot on this. FB DX JG1GPY Takeshi
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I use the same concept here, but mine is primitive! It’s an old gift card cut to give points I can hold between my thumb and middle finger to spool the wire off, and wings I can loop the wire around in a half-hitch to lock the wire at the resonant point. I was going for small and lightweight.
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I could’t find your spool first, but now figured out what you are talking about. Yeah, your antenna is primitive but I guess it is lighter and cheaper! Thank you sharing your antenna. JG1GPY Takeshi
JG1GPY: Greetings! I enjoyed you vedeo and especially like the concept and I would like to build
one for my own use. I have all the materials and tools, but I have a question…how is the connection
made from the antenna to the winding? Do you use some kind of rotating contacts some kind of
rotating connector? I have everything figured out except for that one connection. I hope you can
enlighten me/us who would like to build this for experimation, etc. A drawing or picture with some
explaination would be much appreciated! Thank you and 73, AE5UN.
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The spool you use is similar to the one used in the other antenna. Is it popular in Europe?JG1GPY
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Mot told me that the antenna wire is not connected at the end of spool to the matching part but at the point where the wire is comming out from the box. A smart idea, huh? I hope it helps, JG1GPY
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They are popular i think. I found it in a store for camping accessories and Amazon.
Peter
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I will take a look at Amazon. Thanks!
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Search for “coghlan laundry reel”. Many people use the reels from chalk lines that carpenters and masons use.
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Thank you!