Re: Videotape # 21 is ready (fwd)


index for tape 21 below,


<< Subject: Videotape # 21 is ready
  This new 2 hr. VHS tape covers classic TC, magnifier, and tube
  coil projects.  Tape # 21 index:
  1)  Discussion of large staccato TC,  2) Pulsed action of thyratron on
  large staccato TC is shown, 26" sparks,  3) Circuit is described,  4)
  level shifted (voltage doubler) tube coil is explained,  5) level shifted
  tube plate quickly glows red at high power under certain conditions,
  6) Large choke is used with level shifter,  7)  833A tube is replaced
  with 845 tube with graphite plate, runs cool,  8)  18" sparks are
  obtained from small tube TC after retuning and installing 1kW xfrmr.
  9) Spark gap (disruptive) TC is deliberately enfeebled to compare
  different inductances, primaries, etc,  10)  Further re-tuning of the
  small tube coils gives 17" sparks using microwave oven transformer
  with level shifting, sparks are now more dramatic in appearance,
  11)  845 tube is replaced by HF-300 tube,  12) larger microwave
  oven xfrmr gives better efficiency and longer (19") sparks,  13)  833A
  is re-installed but gives 1/2" less spark length,  14)  Level shifter 
  circuit in installed onto the large tube coil and gives 22" sparks using
  (1) 833A,  15)Staccato action is installed into the level shifted large tube
  coil.  Thyratron control tube flashes in sync with staccato pulsing,
  16) 60 BPS sync-gap tests (spark-gap TC) show better efficiency and
  surging, reaching, sparks,  17)  44" sparks at 600 watts are shown,
  18)  Power input/spark length data table is shown,  19)  30 BPS sync
  gap spark gap TC is tested but gives weak sparks, sounds very weird,
  20)  Discussion of positive feedback mechanisms in quenching,  21)
  Discussion of characteristics of 60 BPS sparks,  22)  Moveable
  mechanized slide table for coil winder is shown,  23) small TC testbed
  for classic TC vs. magnifier comparisons is set up and described, 24)
  Simple coupling measurement method using only ammeter and
  voltmeter is described and shown,  25)  Analysis of RF beats shows
  the effective coupling of a magnifier can be either loose or tight,  26) 
  Various secondary to extra coil ratios are used,  27)  Results are
  tabulated,  28)  Review of quench displays seen on scope,  29) 
  Set-up for modifying vacuum tubes to withstand higher than normal 
  plate voltages, (spark-knocking or debarnacling procedure),  30) 
  Coiling goals, magnifier work will continue on the next tape,
  closing comments.
  To order tape # 21, please send $16 check or MO to:
  John Freau
  49 Thiem Ave
  Rochelle Pk,   NJ   07662
  The price includes shipping by US postal priority mail.
  John Freau >>