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Dim Picture Nanao ms2931

Did you end up trying the resistor swap? IIRC it was originally recommended by grantspain to give the chassis a heater resistor that more closely matches that found on a MS9.
 
I did not. I'll probably try it.

The problem is that a smaller ohm resistor will put more voltage to the heater which could reduce the life of the tube if it's more than 6.3V what these tubes are specced for. Yes, you get a brighter picture, but you're also shortening the life of the tube.

Without accurately measuring the voltage it's all guess work. I don't own a RMS meter so I don't know if that gives at least a ballpark figure. The schematic in the elektrotanya link is for a meter than converts the heater voltage into light and then measures the intensity. It's pretty novel.
 
I think increasing the heater voltage will exponentially reduce tube life. It’s a good thing to do if you have literally no other options.
 
If the voltage is less than 6.3V, that's not good for the tube either. Like I said, without accurately measuring the voltage, it's guesswork.

2930 / 31 seem to reach lower emissions faster than many other monitors, so I wouldn't be surprised if the voltage is more than 6.3V with these chassis.
 
nem said:
I did the resistor swap. It's definitely brighter.

I'll leave the resistor in.

#YOLO
Click to expand...
can you toss me a link to the resistor you bought or a picture. I think sharp image is almost done with my chassis.
 
It's just a regular 2.2 ohm 1W flameproof resistor. I picked it up from a local electronics store.
 
ok I'll try it. I also got a b&k 467 rejuvenater supposedly working but soon as I turned it on got red light to turn on once now nothing.
 
Does anyone know the equivalent resistor on the ms2930 ? Tube is dim, even with a different , recapped chassis.
 
If the heater pins 9 and 10 measure ~6.3V, then the resistor isn't the answer, though. Having talked with @codecrank it sounds like the heater is already at the correct voltage. It might be a good hack to get more brightness out of an EOL tube, but a restore / rejuv is a good first step towards that imo.
 
I have a 2933 with correct tube. If I change the heater resistor from a 3 ohm to 2.2 ohm will it make the picture brighter?
 
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