[NJARC] Mystery radio

[antqradio at juno.com]

OK, I shouldn't have used the term "Vpeak", it should have all been in
RMS.
The math is correct though, the 0.636 term is 2/pi and is used to convert
RMS or effective voltage to average voltage.
I guess of tube loss might be a bit high though, I didn't bother to look
it up.  I just took a stab at it.
But that said, the result is pretty close to what was measured.  I don't
think that the speaker field coil is an effective inductor, just treat 
it as a resistor.  Whatever inductance it has is swamped by the wire
resistance.
Regards,
Jim


On Wed, 15 Feb 2006 11:08:58 -0500 Harry Klancer <klancer2 at comcast.net>
writes:
> Visit our web site - See http://www.njarc.org
> _______________________________________________
> Steve, Jim and Mike,
> 
> Umm. Interesting thread, and I'm really rusty on this, but it seems 
> to me
> that 720 VAC (rms) or, if you flip over alternate peaks, 360 VAC 
> (rms)
> is actually about 360 x 1.414 ~ 509 v (peak). If you lose 50 v to 
> the
> rectifier, you still have about 450 v (peak) or, still assuming 
> full-wave
> rectification, approx. 450 x 0.707 ~ 350 V which should be the 
> effective dc
> value. I am using the peak to rms relationship of a sinusoid here, 
> with the
> 0.707 value. If you were doing half-wave rectification, it would be
> 450 x 0.5 ~ 225 v. Or I could be wrong, and the factor could be 
> 0.636 which
> is the peak to average value.
> 
> I'm not sure about this last part, but I'm confident in the first 
> part about
> the 450 V peak value. So, I don't think we're there yet on the 
> transformer
> question.
> 
> Or maybe it's just the result of 40 years of brain rust on this 
> end.
> 
>                                                      Harry K
> 
> 
> 
> 
> At 2/15/2006 10:31 AM, you wrote:
> >Visit our web site - See http://www.njarc.org
> >_______________________________________________
> >Hi Jim & Mike:
> >
> >Thanks guys...
> >
> >Looks like the numbers are real close..interesting to see the tube 
> sucking up
> >50 volts too...Good math there Jim...I learned something.
> >
> >Mike - you sure put me onto a good reference web site....thanks.
> >
> >Now....how & where can I get these tubes tested???
> >
> >R,
> >Steve
> >_______________________________________________
> >NJARC mailing list
> >NJARC at mailman.qth.net
> >http://mailman.qth.net/mailman/listinfo/njarc
> 
> 
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