Re: [TCML] New 833C VTTC - poor performance

[Kris Grillo <kristianisawesome@xxxxxxxxx>]

Hey list,

I GOT IT!!! I finally found the problem. The grid coil was wired BACKWARDS. I switched the leads and got 18" arcs instantly, without any plate glow! 

Thanks to everyone who offered help. I have learned a lot with this project. Once I recheck all the tuning and tweeking, I'm on to building the staccato controller (the eastern voltage research one). Anyone have any suggestions for a triac?

Thanks again,

Kris


--- On Sat, 8/2/08, futuret@xxxxxxx <futuret@xxxxxxx> wrote:

> From: futuret@xxxxxxx <futuret@xxxxxxx>
> Subject: Re: [TCML] New 833C VTTC - poor performance
> To: tesla@xxxxxxxxxx
> Date: Saturday, August 2, 2008, 1:07 PM
> Kris,
> 
> You have to retune the primary as you increase the power
> and as the sparks get longer.? A primary tune point
> that's best
> for a 10" spark, will be the wrong tune point for a
> 20" spark.
> This is because the length of the spark acts as an extra
> capacitor and changes the resonant frequency of the
> secondary
> while the spark is being produced.? You'll need to tune
> outward
> on the primary, (use more turns), as the sparks get longer.
> 
> This is most likely the problem you're having since I
> can't think
> of any other good reason for the weak sparks and red tube
> plate
> you're seeing.? 
> 
> 20 turns on the grid coil is probably OK.? You can try
> tapping
> off at 16 turns or so, but I doubt it will help.
> 
> Cheers,
> John
> 
> 
> -----Original Message-----
> From: Kris Grillo <kristianisawesome@xxxxxxxxx>
> To: Tesla Coil Mailing List <tesla@xxxxxxxxxx>
> Sent: Fri, 1 Aug 2008 8:03 pm
> Subject: Re: [TCML] New 833C VTTC - poor performance
> 
> 
> 
> John, list,
> 
> "I assume you have a breakout point above the toroid
> (about 4 to
> 5" tall or so maybe)"
> 
> I do have a breakout that extends 4" above the toroid.
> 
> "You have to tune at full power. If you tune at low
> power, the tune point will 
> be wrong at high power."
> 
> I'm not sure what you mean by full power. I brought the
> variac up slowly until I 
> noticed the plate glow, then I backed down a tad and made
> adjustments. I 
> repeated this process for hours. Once I got the primary
> dialed in, I didn't mess 
> with it at all. The power input couldn't change the
> frequency, could it? 
> 
> "I assume your caps can handle the power? Are they
> getting hot?"
> 
> As far as I know, they can handle the power. They are the
> TDK UHV-9A 202K 40KV. 
> One for the tank and one for the grid leak. They were on
> again off again for 
> quite a while and they do not even get warm as far as I
> could tell from 
> occasional touch testing.
> 
> "Also if you have an 833A, you can try that."
> 
> I don't have one.
> 
> "You can try using a higher grid resistance too. Just
> put another resistor in 
> series with the one you have."
> 
> I don't have an appropriate resistor on hand for this,
> but I will pick one up 
> and give it a try.
> 
> Could 20 turns of #26 be yet to many turns for the feedback
> coil?  
> 
> Thanks, 
> 
> Kris



      
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla