[Amps] IMD

[jeremy-ca]

 >If you look at the AL-1200 specs they claim 1200W with 3 tubes so no matter how anyone wants to spin it Im not doing anything different at 750W with two.<
   

  ::The AL-1200 uses a single 3CX1200A7 and runs 1500W output using a tube having 1200W anode dissipation.  You must have a very different AL-1200.

   

  73, Steve WB2WIK/6 

   

  Sorry, I meant the AL-572 which you could just as easily have found by going a bit further on their web site.



  Carl







   

   

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

    From: Steve Katz 

    To: Gudguyham at aol.com ; la7sl at online.no ; amps at contesting.com ; km1h at jeremy.mv.com 

    Sent: Tuesday, September 25, 2007 4:37 PM

    Subject: RE: [Amps] 6 mtrs:

     

    Yep, things do change.

     

    I want to see the spectral analysis of the SB-200 (monoband or otherwise) operating at 750W PEP output on SSB, closing in on IM3-5-7 especially.

     

    When I've used this tube, it's provided only about 8 dB power gain.  With 100W drive that's <750W output, at any frequency.  The Cetron "ratings" per the old data sheet I have is 30 MHz max for full ratings; 7.5 dB gain; 2.4kV max and 250mA max per tube, yielding 300W output per tube (the data obviously assumes 50% efficiency).  At even 65% efficiency to achieve 750W out would be 1153W in, and 403W dissipation from a pair of tubes rated for 320W max dissipation at 30 MHz.

     

    I fully agree anything's possible.

     

    WB2WIK/6

     

     


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    From: Gudguyham at aol.com [mailto:Gudguyham at aol.com] 
    Sent: Tuesday, September 25, 2007 1:28 PM
    To: stevek at jmr.com; la7sl at online.no; amps at contesting.com; km1h at jeremy.mv.com
    Subject: Re: [Amps] 6 mtrs:

     

    In a message dated 9/25/2007 12:36:55 P.M. Eastern Daylight Time, stevek at jmr.com writes:

      But driving a pair of 572B's to 750W output  looks to a retired E 
      professional
      like pushing an old VW beetle to 100MPH would look to an auto engineer:
      Risky,- at best :-)
      May be I am too conservative ??? ...

    Hi Steve, the Sb-200 operators manual says that 100 watts is permissible,  Just because you are used to an SB-200 on HF or similar amplifier that with 100 watts makes only about 650 watts out, then why is the same 100 watts of drive any different on 6 meters?  To me, 100 watts drive is 100 watts drive either on 80 meters or 6 meters.  I think some of you guys have to think "outside the box".  When one fine tunes a design and makes it specific for a specific frequency we are talking a horse of a different color than an all band amplifier.  Things change.

     


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