The Beast
Posted: Thu Mar 25, 2021 9:19 pm
This one has come about due to my 60s oscilloscope BWD 421A mains transformer kicking the bucket and i am unlikely to find a replacement so pretty much junk and now spare parts to me ..nothing lasts forever as they say .
So been studying up on the GEC 1025H cathode ray tube,its the same tube as the 1000 H used in the D 43 Scope pdf posted apart from a different phosphor
its also equivalents are CV8299 SE4D31 what phosphor they use i don't know mines Green as in the phosphor PDF below .
This double gun cathode ray tube with spiral helix PDA was made by GEC-MOV. Also used in the Telequipment D43 scopes.
The tube 1074H is the same tube with different phosphor.
GEC CRT numbering system:
first two digits= screen size in mm =10
next two= screen type. 24 or 74 or 25
24= short, green, as P31 or GH.
74= as 24 with Aluminised screen (by adding 50 to phosphor type)
the 25 screen is short, green-yellow, as P2 or GL.
Letter indicates tube type/characteristic. H = two guns, with PDA.
The CRT is of interest dual deflection as it will push me to learn how to tame this Beast thus the name
Rather interesting Tube with 2 guns 2 sets of deflection plates for the Y The X i think it uses one half for either gun or perhaps you could use both for one gun ,unless i am misreading the D43 scope schematic .
So 2 EHT supplies also needed for this and some other supplies as shown in the D43 Schematic and data .
The Mu metal screen was rather grubby so cleaned that and gave if a paint job for the New Project ,i also had a case large enough to reuse for this
Now the Tube needs to be mounted as its not safe with these power supplies ,so this step is where i am up to took a little while to work out the best way with the case i have .
The 2 silver panels and hidden door panel will hold the controls ,still need to cover holes back of case .
This CRT is all experimental depending on how well i can control it will depend on how it ends up ,what i would like it to do is similar 2 the 240 line 2 hz frame rate test on the Devil monitor but horizontal scanning so something like 120 180 240 line frame rate select ..using low frame rate i can use the audio bandwidth of my PC to display higher quality which would be lost trying a higher frame rate also the phosphor is a little longer so more suited to a low frame rate ..any case if it gets to this stage i will play around here.
I forgot if i can also do a dual display i will do something similar to the Binocular monitor but unlike having a sperate CRT for the scope and have a scope display below the video image on the same crt ,well want and can do depends first up if i can light this Beast .
OH well Fingers crossed one hand behind my back and here we go again ...
So been studying up on the GEC 1025H cathode ray tube,its the same tube as the 1000 H used in the D 43 Scope pdf posted apart from a different phosphor
its also equivalents are CV8299 SE4D31 what phosphor they use i don't know mines Green as in the phosphor PDF below .
This double gun cathode ray tube with spiral helix PDA was made by GEC-MOV. Also used in the Telequipment D43 scopes.
The tube 1074H is the same tube with different phosphor.
GEC CRT numbering system:
first two digits= screen size in mm =10
next two= screen type. 24 or 74 or 25
24= short, green, as P31 or GH.
74= as 24 with Aluminised screen (by adding 50 to phosphor type)
the 25 screen is short, green-yellow, as P2 or GL.
Letter indicates tube type/characteristic. H = two guns, with PDA.
The CRT is of interest dual deflection as it will push me to learn how to tame this Beast thus the name
Rather interesting Tube with 2 guns 2 sets of deflection plates for the Y The X i think it uses one half for either gun or perhaps you could use both for one gun ,unless i am misreading the D43 scope schematic .
So 2 EHT supplies also needed for this and some other supplies as shown in the D43 Schematic and data .
The Mu metal screen was rather grubby so cleaned that and gave if a paint job for the New Project ,i also had a case large enough to reuse for this
Now the Tube needs to be mounted as its not safe with these power supplies ,so this step is where i am up to took a little while to work out the best way with the case i have .
The 2 silver panels and hidden door panel will hold the controls ,still need to cover holes back of case .
This CRT is all experimental depending on how well i can control it will depend on how it ends up ,what i would like it to do is similar 2 the 240 line 2 hz frame rate test on the Devil monitor but horizontal scanning so something like 120 180 240 line frame rate select ..using low frame rate i can use the audio bandwidth of my PC to display higher quality which would be lost trying a higher frame rate also the phosphor is a little longer so more suited to a low frame rate ..any case if it gets to this stage i will play around here.
I forgot if i can also do a dual display i will do something similar to the Binocular monitor but unlike having a sperate CRT for the scope and have a scope display below the video image on the same crt ,well want and can do depends first up if i can light this Beast .
OH well Fingers crossed one hand behind my back and here we go again ...