Old Sony SE OPT's /w 600r tap... cathode feedback maybe?

[Zen Mod]

Hmmm... do you think "signifigant" as in + 10%, or 'signifigant' as in+30% or more?

hehe
time for vote


computing that is simple
all you need is to calc dissipation in that winding

then (using wire gauge,calculated mass of wire) calculate increasing in temperature of winding

then-using tempco for Cu ,calculate increasing of R............


nah- you can't calculate increasing of temperature in real life xformer winding,if that xformer is not in steady condition; there is musak pulsating through it.......😉


time for measure,enough voting


sole restricting factor in this test is -gauge of 600 ohm winding ;
is it wire diameter big enough for no more than 2A/cm^2 in dynamic conditions?
for answering that-all you need is micrometer and calculator

 

[aletheian]

I think I'll go ith the good 'ol fashioned, "try it and see". At least in this instance, the only REAL danger is biasing the tube too cold. Theoretically, I would only be running about 40mA through it from the cathode, so it should be able to take that without too much sweating.

 

[Dave Cigna]

Hmmm... do you think "signifigant" as in + 10%, or 'signifigant' as in+30% or more?

10% would imply a rise in temp of almost 30C. I would say that's an upper limit. If you get more than 10% then you're probably running more current than you should.

-- Dave

 

[rdf]

At least in this instance, the only REAL danger is biasing the tube too cold.

More an advantage than a danger I think. You probably want some resistive loading across that secondary winding to terminate it anyway.