[Boatanchors] More on Carbon Comp V ratings

[Brian Harris]

Barry,

Just because a resistor has B+ (600V) on one end does not mean it has 600 Volts across it. If you have a 20K resistor from B+ to a tube screen which is at 300 Volts, then the 20K resistor has 300 Volts across it. No problem for a 350 Volt capable resistor.  By the way, if you are going to be working with vintage gear you might to start picking up NOS carbon comp resistors at hamfests whenever you find them.  I have thousands of them and that's not enough.  One more thing, before you replace all those resistors be absolutely certain your meter is correct. Also, I don't typically change a resistor unless it is more than 20% off but I am an electrical engineer with 50+ years of experience in electronics so I make judgements calls.  Good luck.  WA5UEK

Sent from my iPhone

> On Feb 15, 2018, at 9:16 AM, Barry Pfeil <barrypfeil at gmail.com> wrote:
> 
> Wow, you guys really like to go at it!  Thanks for all the info and
> opinions on my first post.  Getting back to my little Adventurer, FYI the
> parasitic chokes are actually wound on 100 ohm resistors and, since I can't
> measure them in-circuit (DC short) I'll probably replace them just to be
> sure since half the other carbon comps in the rig are way high.  But some
> of the other bad resistors WILL definitely see B-plus, which is 600V in
> this rig, so my question about resistor voltage ratings still stands,
> David (K6XYZ?) suggested Ohmite OX or OY.  Any other thoughts?
> 
> BTW, nice to see those 50 year old 10W wire wounds made by IRC are still
> right on the money in resistance value.
> 
> Thanks again ES 73,
> Barry K6RM
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