[Amps] NCL-2000

[Carl]

Ground the cathodes as designed and try again. 

Carl



  ----- Original Message ----- 
  From: HOWARDLYON at aol.com 
  To: amps at contesting.com ; km1h at jeremy.mv.com 
  Sent: Friday, February 01, 2013 1:04 AM
  Subject: NCL-2000


  Hi Carl

  Finally getting back to the NCL-2000.  I shotgunned the HV supply and a new HV relay a couple years ago.  Same deal as the SB-220 PS job; 105*C radials in series/parallel; new diodes and bleeders.  The Heath has been purring for two years now, so should oughta work for the National, too.  Finally getting back to it now.

  I did the Kathode resistors (33-ohm x 3 for each socket).  Think that was a Rich Measures mod.

  Fired her up with the interlocks defeated.  Adjusted bias for 225mA.  Tuned and loaded for 40m into a Cantenna.  Drove her with my olde TS-530; adjusting drive with the Carrier control.

  Two things noted..... only about 3-5mA of grid.... and the screen metering jumps to about 40 or 50, and then slowly rolls back to 15mA.  

  Do I use the initial jump, or the pacified 15mA for the critical screen load?  Do I need more C shunt on the screen metering?

  Is the <5mA grid OK?  Or, indicative of....?

  Thinking of installing a 160 mod over top of the fan motor; around the phenolic, anti-shorting stick; and over the plate resistor and output choke.  I have about 2" high x 4" wide x 8.5" long.  Looks like enuf room for the toroid over the blower, the vac relays hanging between the blower and the stick, and the padders over the choke and the SO-239.  Even enuf room for a small relay PS, I think.  Is this worth the trubs?  Gud or bad idea?

  Thanx for the help.

  Unca Billy
  N3TR

  Wm. H. Taylor 
  General Contracting and Design 
  2249 Hickory Hill Rd 
  Oxford, PA 19363 
  610-932-3762 h 
  484-643-3220 c 
  n3tr at arrl.net

  Historical Restoration; Custom Stonework; Fireplaces
  Star Bolts; Structural repairs 



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