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Old 7th Oct 2021, 6:27 pm   #1
AdrianH
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Join Date: Mar 2020
Location: Blackburn with Darwen, Lancashire, UK.
Posts: 1,097
Default 5FP7 project starting with the focusing coil.

The eventual plan is to build a valved old fashioned SSTV/NBTV monitor using this ex RADAR tube for the display. It is also a learning exercise for me, in that I hope to understand more of the principles of electro-magnetic deflection.


Although I believe, a LOPT will not be driving the scans for such a slow unit I also want to understand these better and how they work and are calculated etc. So as time goes on expect lots of questions that may seem trivial, but please understand before taking up the hobby I was not a TV engineer.


The coil former was turned from black nylon, 42.35mm diameter and 52mm long where the wires will go. I then parallel wound 7000 turns of two 0.16mm dia, enamelled wire, giving a max rating of around 12mA.


It takes 66mA to focus the spot at 2KV EHT and 82.5mA at 3.5KV EHT. Scan coils and static deflection to follow at some point.

https://youtu.be/BU0NfyYazbI


Adrian
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