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#1
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If you could post the schematic(s) of the power supply and deflection circuits, the collective wisdom available here should probably be able to walk you thru it.
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#2
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I have been working with the schematic from early television. I don’t remember what the b+ should be 125v or 150v
Last edited by timmy; 02-03-2024 at 03:46 PM. |
#3
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The riders shows 150v but when I recapped this set the b+ was low 90v so I added a diode to the positive rec tube and I think it came up to 125v so to bring the b+ up would I add a second diode in series with the one I put in already.
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#4
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But what would be the best path to take in raising the b+ or would resistors have to be changed from b+ to the vertical
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#5
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In addition to trying to get more sweep voltage to the plates, it may also be a factor of adjusting the coupling caps / resistors .005uf /47m to better match the new tube to make what you give it most effective, but have no idea what it may or may not have to be changed to!
__________________
=^-^= Yasashii yoru ni hitori utau uta. Asu wa kimi to utaou. Yume no tsubasa ni notte. いとおしい人のために |
Audiokarma |
#6
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Well I’m thinking of adding another diode in series to see if this makes any difference
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#7
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as far as I know putting in another diode will lower the voltage.
__________________
=^-^= Yasashii yoru ni hitori utau uta. Asu wa kimi to utaou. Yume no tsubasa ni notte. いとおしい人のために |
#8
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In series it should come up some I think. There’s one in there already if it don’t come up I don’t know what else to do to get the voltage up more to see if it makes any difference
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#9
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Quote:
ANY diode, no matter the type, solid or tube type, will have a forward voltage loss, solid having the least, and schottky type having the lowest forward loss. the more in series, the more the loss
__________________
=^-^= Yasashii yoru ni hitori utau uta. Asu wa kimi to utaou. Yume no tsubasa ni notte. いとおしい人のために |
#10
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I had put a 1n4007 at the 25z6 positive tube and the voltage came up from 90v to iirc 125v common for these sets to have low b+
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Audiokarma |
#11
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Series’s meaning I would add another to the one in there now
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#12
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The only thing that makes sense to me to raise positive bias is to remove the 25z6 and replace with one1n4007 , leave the heater connected, and wire in the diode from the 10 ohm resistor on the plates to the 40 UF / spkr field coil, making sure to keep the cathodes p 4/8 unhooked.
This will raise the B+ by a lot, but may also have an effect on the negative bias.
__________________
=^-^= Yasashii yoru ni hitori utau uta. Asu wa kimi to utaou. Yume no tsubasa ni notte. いとおしい人のために |
#13
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Quote:
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#14
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the forward voltage of the 25z6 is 22v and the forward voltage of the 1n4007 is lest than one, you gain almost 21v by changing to so;id state.
__________________
=^-^= Yasashii yoru ni hitori utau uta. Asu wa kimi to utaou. Yume no tsubasa ni notte. いとおしい人のために |
#15
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Well that would bring it close to 150v as riders says
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Audiokarma |
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