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Old 9th April 2012, 11:33 AM   #631
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Tried the dual resistor trick in above example and it was a no go. Something is not right. I am wondering if i need to increase resistor value. THe dual 100R resistor seemed to sink all the current from the tube. I connected ground point to first node of filter, should I have taken int to common ground?
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Old 9th April 2012, 08:55 PM   #632
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I need some help with this. I tried the two resistors tied on one end to each filament and other end tied together on to ground point at first cap. It not only didnt work, it caused smoke. This makes no sense to me except for a reference somewhere about not tying the ground point of dual resitor setup to cap due to spikes in voltage. also saw where some put a cap between dual resistors and ground. What am i doing wrong here. I have a 1K pot to try humdinger, maybe 500ohm, but i cannot find any diagram that shows something different than what I have done. I really want to listen to this thing, because i can tell it has changed, even with the hum.
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Old 9th April 2012, 09:11 PM   #633
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Better show a diagram of what you are doing so it will be easier for members to comment I think.
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Old 9th April 2012, 09:35 PM   #634
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Here ya go. Picture is actually slightly incorrect. The CL60 and .15R resistor come after the joining together of the two 6.3V secondaries.
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Old 9th April 2012, 10:56 PM   #635
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Those 100R would drop all the heater voltage and get smoking. They could be located at each plate in series with the 330V taps instead of having a single 165R for damping maybe.
100R+100R in non center tapped heater secondaries they use between them not in series, to ground reference or voltage lift AC heated signal tubes.
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Old 9th April 2012, 11:08 PM   #636
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how Salas ?

they're dissipating around 100mW each , from 6V3 heater voltage


edit:
whoa!!!!!!!!!

I didn't saw that buzz connect them to gnd !!

sorry - they will be tossed , but not drawing from heater winding
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Old 9th April 2012, 11:09 PM   #637
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Quote:
Originally Posted by Salas View Post
Those 100R would drop all the heater voltage and get smoking. They could be located at each plate in series with the 330V taps instead of having a single 165R for damping maybe.
100R+100R in non center tapped heater secondaries they use between them not in series, to ground reference or voltage lift AC heated signal tubes.
are you saying that the 100R should not be connected to each other. Could you draw a pic. This is not making sense as everything I have seen shows this kind of setup, but clearly I am missing something. IT would seem that having the two resistors tied together would indeed make a series connection were one should not be, bypassing the internal connection of the heater.
For instance, the link i posted earlier,
The Valve Wizard
what am I missing here?. I know its me, but i dont get it.

FWIW, my star ground point is chassis, with single wire going to earth. I have not lifted starground, but everything I have read seems to suggest this is ok for PSU.
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Old 9th April 2012, 11:38 PM   #638
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point is in "signal valve"

you need to reference heaters of those to some potential (ground or lifted) , not rectifier tube's heater
it's either made as DHT or IDHT (often with cathode+heater tied) ....... and - look! - magically already referenced to Ub+

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Old 9th April 2012, 11:46 PM   #639
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So, do i have recourse for my hum other than winding custom balanced secondary with CT as TRiode Al suggested?
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Old 9th April 2012, 11:50 PM   #640
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As Zen explained in more words, see what you did to B+. Did those two resistors in the red path smoke?
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