Wednesday 16 October 2024

Parabolic Umbrella update

It has been an enjoyable few years experimenting with fabric antennas and i'm happy to have been featured on Tech Minds youtube channel this week. I feel very lucky to have this attention from the amsat crowd and I am indeed an amateur just like everyone in the hobby. Making things has always been something which I have delved into to help me learn about things which I find interesting, I come from a tech background, something which I have studied too at university level, my early childhood learning was surrounded by artists, painters & sculptors. Making things with my hands has always been there along the way. I think it was around 2010 when I built my own 3d printer, and in 2016 I built my own cnc router and along with this I learned how to use cad design software to help me come up with answers to ideas in my head; I think it is this early art exposure which made me see the world a bit differently, to look around, to read articles, to hear stories. It was in 2019 when I was sitting thinking about alternatives to aluminium mosquito screen door mesh for antenna building as I felt it was unsuitable due to it not collapsing thus cancelling out portability, being sharp with splinters once cut and trimmed, and only being semi rigid. I was sat one day thinking about alternatives and saw something called RFID Blocking fabric and having not seen it being used in any antenna designs before, my mind considered if it was not just blocking but reflective of radiowaves so I gave it a try and was stunned by it's performance and potential, I knew it was right for me, my discovery was made which led me to my invention which is starting to lead to other amateurs coming up with their own ideas. I might sometimes interpret things in a way which may or may not be on the path of normality. However I learned that it is my interpretation and in art how can that be wrong but for other people to decide.


I have had the pleasure of having buyers of my ideas as varied as aerospace engineers, corporate aerospace seniors, prop departments, youtubers, even hollywood film studios, Sony Pictures, Shinfield, Culver City, Hamburg prop companies, Raytheon, Boeing, Bletchley, King Saud University, and so on, this past few years of fabric exploration.


My designs are forever being adjusted, and my iterations change as I go along. I have experimented with glass fiber poles, aluminium mosquito door mesh, real rain umbrellas, beach balls, lots and lots of different designs. I experimented at the beginning with true parabolic designs, and indeed i still do. But the one design I believe true to myself is the design I sell right now. It is a compromise on manufacturing. As I live in a small humble flat with a cramped backyard shed I use the tools and parts that I have available and I build things to mass produce according to the time I feel I can put into making them and I judge the price by a few rules, postage price, ebay sales cut percentage, international fees, parts purchasing, my time, what i feel it is worth, packaging time, packaging supplies, tools and sundries. That is the way of iphones, cars, sneakers, farming, basic economics. I am not blind to the path I choose in my design, and in my backyard shed I have other designs which I do not sell due to the costs of the list above being too great to do repeatedly, so I choose to release the things I make as a reflection of what I have available. There has been no crowdfunding sought, no wish to deceive, no investment from banks or private investors to help me with machinery or workspace, nor do I have any access to the old university research cash fund. I do what I do in the best way I do. Doo Bee doo doo.

As a further update to my umbrella designs I wish to help the amsat community who have not used one of these antennas, or a fabric antenna, but have attempted to decide that the antenna is a flat circle, or that it is not parabolic in any sense. Some adjectives describing it have been rather well suspicious and I do have knowledge of pernicious activity going on but I  have better things to do than wander down that path.

Anyway, here are a few photos of my backyard shed antennas in my backyard shed being made and I present them with a flat bamboo cane sat across horizontally to help show just what shape it is.

 


 And you will find if you want to be more exact about the design it would likely be described as a truncated cone, or conical frustum. And according to antenna design perfectly capable :) 


As per the idea that this is flat, shallow or unsuitable I pledge to differ about that, afterall a parabola is in fact just a conic section of a cone and by that definition the parabola owes much to the cone.

Compared to my 1.2m offset dish:


And as per lacking suitable gain, I ask that you read my previous post which has images showing screenshots of it in use and both the swr (db) and peak swr (db) which was actually better than my early parabola design. One of the reasons I chose to add parabolic in the title of the ebay listing is precisely because of that, an ebay listing will only attract buyers who search for certain keywords and by adding the word it will hopefully reach more prospective buyers.

Thanks for reading and who knows if the fabric cone shall become a parabola again (or if it is necessary as I already explored) :)

Also here is an early parabola design iteration with bendy fiberglass poles and sure looks fancy futuristic cad prints but takes a hella time. Feel free to read my past posts for more on that.

Parabolically conical.