Re: VTTC output

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

Original poster: "David Trimmell by way of Terry Fritz <twftesla-at-uswest-dot-net>" <davidt-at-pond-dot-net>

Herwig, It looks like you are getting very good performance from a 1KW
tube, but without more info it is hard to tell. How much plate current
were you pulling? How many wall watts? What is the Fr0 of the
secondary? And how much filtering were you using for your B+? I hazard to
say that if you go to a Level Shifted half wave approch to feeding the
plate you could get substantially longer sparks. Is there a particular
reson why you are wanting filted DC? Also the primary wire seems very
thin, #15? (AWG American Wire Gauge?), impresive that it wasn't getting
hot! I use #12 and it will get warm after a couple minuts of 2 KW Filtered
DC, whimpy 4-5 inch flame, ;-)

Regards,

David Trimmell

On Tue, 13 Feb 2001, Tesla list wrote:

> Original poster: "Herwig Roscher by way of Terry Fritz
<twftesla-at-uswest-dot-net>" <herwig.roscher-at-gmx.de>
> 
> 
> Hi all,
> 
> Trying to maximize the output of my system, I'm wondering what 
> the best methode could be. Pure observation by eye IMO is not 
> exact enough, especially at daylight conditions. Is monitoring the 
> value of the current flowing into the base of the secondary a better 
> choice? Which methodes do you use?
> 
> Some data of my system (please use constant distance font):
> tube            : 4PR1000
> plate           : 10 kV filtered dc
> screen grid     : up to 1000 V
> primary L       : 67 turns on 8" form
> primary C       : 714 pF
> secondary L     : 1370 turns on 4" form
> secondary C     : toroid/corona shield 1.18" x 6"
> sense resistor  : 5.1 Ohms between base of                         
> secondary and GND
> coupling        : secondary 1.2" above primary
> grid coil       : 8 turns on 8" form, 1.2" below primary
> grid leak R     : 30 kOhm
> grid leak C     : 3.7 nF
> 
> grid current    : 10.6 mA
> grid voltage    : 320 V
> sense voltage   : 20 Vpp, sinusodial (!) 
> 
> The brush is about 15"long and very intensive blue, starting from a 
> horizontal piece of rectangular aluminum sheet atop the toroid. 
> Reason: The toroid is made from foam and covered with aluminum 
> foil. Using a small discharge pin caused overheating and burned 
> the toroid. I'd better made it from copper tube!
> 
> Could I expect more output? At present primary (about AWG 15) 
> and secondary (about AWG 26) barely get warm. Much space for 
> improvements?!?
> 
> Any advice is appretiated very much.
> 
> Herwig
> 
> 
> 
>