[Amps] Alpha 76A drive levels...

[Carl]

The tubes are rated at up to 30ma each so you can run them all at 60ma as now until they need replacinrg or a 2 x 3CX800A7 conversion.

I tune using the grid current peak only using the Load control to increase or decrease the grid current and the Tune control to do the peaking.

Carl



  ----- Original Message ----- 
  From: tz4am at aol.com 
  To: km1h at jeremy.qozzy.com ; amps at contesting.com ; wa6fgi at steeltrails.net 
  Sent: Wednesday, January 02, 2019 4:32 AM
  Subject: Re: [Amps] Alpha 76A drive levels...


  Carl:  


  I have a 3-holer, with so-so tubes.


  On 40 meters on the SSB setting, tuning to keep grid current maximum at no higher than 0.6 on the scale and a dip in plate current, I get about 1 KW forward power; it takes about 87 watts to get this output with so-so tube.


  On other bands, the same procedure yields about 850 watts with drive of between 40 and 60 watts.


  Is this the right procedure for tuning or should I be doing things differently?


  73,

  Jeff


  -----Original Message-----
  From: Carl <km1h at jeremy.qozzy.com>
  To: tz4am <tz4am at aol.com>; amps <amps at contesting.com>; wa6fgi <wa6fgi at steeltrails.net>
  Sent: Wed, Jan 2, 2019 2:24 am
  Subject: Re: [Amps] Alpha 76A drive levels...


  As low as required to peak the output at 1200W, about 30-40 ma total with 

  used tubes at 60W or so.



  I bought this amp as a basket case, bad tubes, transformer, bandswitch, etc, 

  so do not know what it did when new.



  Carl







  ----- Original Message ----- 

  From: tz4am at aol.com

  To: km1h at jeremy.qozzy.com ; amps at contesting.com ; wa6fgi at steeltrails.net

  Sent: Saturday, December 29, 2018 11:02 AM

  Subject: Re: [Amps] Alpha 76A drive levels...





  Carl,





  Thanks for the information. What is the grid current reading at 1200w?





  Jeff

  TZ4AM







  -----Original Message-----

  From: Carl <km1h at jeremy.qozzy.com>

  To: amps <amps at contesting.com>; Gary Smith <wa6fgi at steeltrails.net>

  Sent: Sat, Dec 29, 2018 2:59 pm

  Subject: Re: [Amps] Alpha 76A drive levels...





  Alpha offered a low drive mod for that series of amps, check their legacy



  amp docs.







  My 76PA 3 holer will easily run 1800W with100W drive, I back it down for



  1200W.







  Carl







  ----- Original Message ----- 



  From: "Gary Smith" <wa6fgi at steeltrails.net>



  To: <amps at contesting.com>



  Sent: Sunday, December 23, 2018 5:06 PM



  Subject: [Amps] Alpha 76A drive levels...











  > To the group:



  >



  > Have a friend who recently purchased a Alpha 76a two-holer.



  >



  > He currently is driving it about 65 watts getting 500 watts or so output.



  >



  > As he has no instructions on the amp, is this low level of drive okay or



  > should it be driven at a higher level of input power.



  >



  > Thanks to the group,



  >



  > Gary...wa6fgi



  >



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