The grid as far as I know in theory, is supposed to be only influenced by
primary. But I have found it could come into play if up too high,
secondary higher built up voltage on windings on the way up secondary seems
to influence this, from what I have found, it will cut out the tube in the
grid. Not much current will flow. No matter however you change the grid
leak circuit.
Chris
Sent from my LG
On Dec 14, 2017 9:59 PM, "David" <zipo@xxxxxxxxxxx> wrote:
John thanks - 16" sparks from an 810, wow I would be happy with 11. I am
using a level shiftier w/ 2uF and the plate can get very red if I push it.
I have a milliamp meter on the ground side and it easy gets to 300ma or
more using a 140v variac. The tube can get very red if I push it to 250 to
300ma or more and that's at ~50% on the variac. I've ajusted primary turns
from 36 to 44 with very little change. I've adjusted the height of the grid
coil with little change tho it seem to work better the higher it is. Does
the grid coil couple with the primary coil or the secondary? Steve was
using a Staccato controller and I'm not yet. I'm using component values and
set up as outline on Steve's page. For spark capacitance on Java TC I add a
small diameter cylindrical topload by the length of spark in addition to
the toroid and it seems to be pretty close. For tube coils is the tank
suppose to match the secondary res frequency with spark and topload?
Dave
On 12/14/2017 8:22 PM, Futuret via Tesla wrote:
> Dave,
>
>
> If you're using the voltage doubler (level shifter), then you should
> get 16" sparks like Steve got. Does the plate of the tube get dull
> red if it runs awhile? This might be seen more easily in a dark room.
> If the plate gets red then it means the tube at least is capable of
> strong emission. Even without the doubler it should produce 11"
> sparks. However the coil will need to be tuned differently for
> high power vs. low power operation to adjust for the
> capacitance provided by the spark length. Is the 810 tube known
> to be strong and good? A weak tube will give weak sparks, and
> the plate will never get red (or probably won't). If you used JavaTC
> or some other program to tune the coil, you may need to use a 50%
> larger capacitor than the program suggests to adjust for the
> capacitance of the spark. I think JavaTC might have a feature
> that takes spark capacitance into effect (I forget). If it does then
> that can be used. But it still might need to be tuned a little
> differently. Also Steve might be using a step up type variac
> which can provide up to 140 VAC to the coil. That makes a
> large difference in spark length compared to using just 120 VAC.
> An easy way to check the tuning is to install different sized
> toroids (or no toroid), and see if the sparks get weaker or
> stronger. Here's my website where I show a smaller VTTC project.
>
>
> https://sites.google.com/site/jfuturet/home
>
>
> John
>
>
>
> -----Original Message-----
> From: David <zipo@xxxxxxxxxxx>
> To: tesla <tesla@xxxxxxxxxx>
> Sent: Thu, Dec 14, 2017 3:54 pm
> Subject: [TCML] 810 tube coil
>
> Hello everyone - I have completed my first tube coil using a 810 triode
> based on Steve ward's 810 coil outlined here,
> http://www.stevehv.4hv.org/VTTC4.htm
> I've almost exactly copied his design but with mica transmitting caps.
> I've been working with trying to tune primary turns and adjusting grid
> coil height and turns and have been getting ~4" sparks from the breakout
> point, I would have expected more.
> I'm not using a staccato yet but how much should I expect from a coil
> like this at 60Hz?
>
> Thanks
> Dave
> _______________________________________________
> Tesla mailing list
> Tesla@xxxxxxxxxxxxxxxxxx
> https://www.pupman.com/mailman/listinfo/tesla
>
> _______________________________________________
> Tesla mailing list
> Tesla@xxxxxxxxxxxxxxxxxx
> https://www.pupman.com/mailman/listinfo/tesla
>
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxxxxxxxxxx
https://www.pupman.com/mailman/listinfo/tesla
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxxxxxxxxxx
https://www.pupman.com/mailman/listinfo/tesla