Corby Curious if you ever received any other comments or had success? Regards Paul WB8TSL
On Mon, Jan 16, 2017 at 5:07 PM, paul swed <paulsw...@gmail.com> wrote: > Corby thats a heck of a puzzle. I am trying to think about how you could > prove it. I have some thoughts that are not at all well formed. It comes > from my experiments on Frankenstein temp control. > > If you could please tell me what you might expect the alternate bridge > resistors to be overall I will look through my various bits to see if there > is anything. > > Regards > Paul > WB8TSL > > On Mon, Jan 16, 2017 at 3:58 PM, <cdel...@juno.com> wrote: > >> I've been doing some work on testing some HP 5061A/B tubes >> and came across something that's not making any sense! >> The R11 and R12 values marked on the tubes for use with the >> new style A11 are supposed to reflect a parallel value >> that is 10X larger than the thermistor reading. >> This to agree with the ratio of the bridge resistors in the >> A11 module. >> For instance a 3112A prefix tube shows values of 3.83K >> and 42.2K. This gives a parallel value of 3.511K which when >> divided by 10 gives 351.1 Ohm. The value marked on the tube >> was 352 Ohm. That all makes sense! >> Now I have three 3232A prefix tubes and they all do not >> reflect this ratio. >> For instance one has values of 51.1K and 5.11K which gives >> 4.65K. This divided by ten gives 465 Ohms. However the >> Thermistor value marked on the tube is 915 Ohms! >> I tested all three tubes and they come up to the proper >> temperature with the thermistor value marked on the tube. >> Did HP make a change to the A11 bridge resistor ratio, and >> if so where did they document it! >> If not and you used the R11 and R12 values you would >> seriously overheat the tube! >> >> Cheers, >> >> Corby >> >> _______________________________________________ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to https://www.febo.com/cgi-bin/m >> ailman/listinfo/time-nuts >> and follow the instructions there. >> > > _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.