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  #91  
Old 11-06-2014, 10:14 AM
old_coot88 old_coot88 is offline
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In the absence of a width sleeve or an operative width control, there's a coupla ways to reduce width.

1. increase the value of the resistor feeding the screen grid (G2) of the H output tube. This reduces the voltage on G2.
First try about a 5% increase in value of the resistor, and go from there.

2. Add resistance in the cathode leg of the H output tube. Try 50 ohms as a starting point.

The caveat to these methods is that HV is reduced proportionately with the width.
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  #92  
Old 11-06-2014, 11:02 AM
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Username1 Username1 is offline
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You could add resistance to the horiz. winding on the yoke.... No real HV issues....
You may have to change the timing cap for the discharge loop..
eh.... probably not....

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Last edited by Username1; 11-06-2014 at 11:23 AM.
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  #93  
Old 05-22-2015, 10:10 PM
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MIPS MIPS is offline
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Dammit.
Set has been gradually losing control over vertical hold over the last six months and now it finally reached the point where after a few minutes no fiddling with the vertical hold will cure it. Looking at my old worksheet I've already changed out the resistors around the vertical hold control and the 12BH7 still tests good but there's three other resistors around that tube I can only suspect are drifting out as they warm up.
Back onto the bench it goes. UGHHHHHHHH.
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  #94  
Old 04-02-2016, 10:07 AM
broadcaster broadcaster is offline
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Great job on the cabinet!
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  #95  
Old 04-09-2016, 05:15 AM
ronl ronl is offline
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Hi MIPS ,
perhaps try anouther vert tube or 2-just because it tests good doesnt mean its gonna work properly in cct or be temp stable.
if you need a tube, i can look through my stash for a free used one.you are not that far so shipping would be cheap, or if you are heading into Van in the next while,feel free to drop by and p/u. if i got a few ,i can send you several to try.
RonL
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