Re: 811a coil/ bad diode?

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "rheidlebaugh by way of Terry Fritz <twftesla-at-qwest-dot-net>" <rheidlebaugh-at-zialink-dot-com>

Steve: I hope you are saying micro wave oven diode not micro wave diode. Big
differance.  You are correct  Your schematic you posted is not correct.  The
schematic of my coil I sent uses the tube as a diode to rectify the AC power
in. Your circuit uses the diode to produce a negative grid bias, with
correct conections you could use your tube as your rectifier also. Hy 811
coil gets about the same spark length as yours with out overdriving it.
   Robert  H

> From: "Tesla list" <tesla-at-pupman-dot-com>
> Date: Thu, 04 Jul 2002 12:52:15 -0600
> To: tesla-at-pupman-dot-com
> Subject: 811a coil/ bad diode?
> Resent-From: tesla-at-pupman-dot-com
> Resent-Date: Thu, 4 Jul 2002 12:57:18 -0600
> 
> Original poster: "Steven Ward by way of Terry Fritz <twftesla-at-qwest-dot-net>"
> <srward16-at-hotmail-dot-com>
> 
> Hi group,
> 
> I think that i may have come across my problem with my small VTTC that ive
> been working at for awhile.  I decided to check out all of my components
> today and found that my diode is not testing good.  It reads open circuit in
> both directions.  Is this a sign of a bad diode?  I know that it would
> usually be, but are microwave diodes different?  Another diode (suspected
> bad as well) i have reads 4kohm im both directions.  I think i may have
> blown the diode when someone on this board told me that the schematic was
> incorrect.  I followed his directions, and blew a 15A fuse, and was probably
> quite close to blowing my tube! im sure that amount of power could destroy
> that little diode.  So i followed the original plans and the coil works OK
> giving about 3" sparks at most, with unopredictable performace from time to
> time. Ive been running the coil for a few days with out realising my diose
> may be bad.  This makes me suspect the diode.  So do i need a diode?  or can
> i bypass it?  a new diode isnt much of a problem but i want to know it i
> even need it, and if i dont what other modifications do i need to make?
> Thanks,
> 
> Steve Ward.
> 
> 
> 
> 
>