UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - 5FP7 project starting with the focusing coil.

dalekmoore2007 · 9th Oct 2021, 11:46 am

Hi Adrian !
I see we are very like minded on the CRT interest ...Nice tube .
Below is my you tube channel top line my NBTV SSTV system 240 line with a very low frame rate keep it all in audio bandwidth .

https://www.youtube.com/channel/UC9e..._E3FpVgyObW8LA

Yes as you know i too with valves are trying the same sort of idea my tube is faster than yours ..

I infact had your CRT tube about 1990 before i moved to Melbourne and made a SSTV with it ,it stated out as a failed project by another constructor who gave it to me , so i didn't have to wind the focus coil thank goodness ...but it sort of put me off focus coils as i found after a bit of use the coil heated up a bit and would defocus the raster spot a bit .
i think it would of needed more turns to fix this .

I would work on deflection easy to burn your CRt with out this .or run it very defocused.

9th Oct 2021, 11:46 am	#4
dalekmoore2007 Pentode Join Date: Aug 2008 Location: Melbourne, Australia Posts: 213	Re: 5FP7 project starting with the focusing coil. Hi Adrian ! I see we are very like minded on the CRT interest ...Nice tube . Below is my you tube channel top line my NBTV SSTV system 240 line with a very low frame rate keep it all in audio bandwidth . https://www.youtube.com/channel/UC9e..._E3FpVgyObW8LA Yes as you know i too with valves are trying the same sort of idea my tube is faster than yours .. I infact had your CRT tube about 1990 before i moved to Melbourne and made a SSTV with it ,it stated out as a failed project by another constructor who gave it to me , so i didn't have to wind the focus coil thank goodness ...but it sort of put me off focus coils as i found after a bit of use the coil heated up a bit and would defocus the raster spot a bit . i think it would of needed more turns to fix this . I would work on deflection easy to burn your CRt with out this .or run it very defocused.