[Elecraft] K3 losing RF power

[Jeff Cochrane - VK4BOF]

Paul,
It sounds to me like you have a voltage drop issue on transmit.
Have you checked your power supplies voltage under load and the supply leads to the radio?
That's where I'd be starting to look first.


Jeff Cochrane - VK4BOF
Innisfail, QLD, Australia
Elecraft K3# 4257

  ----- Original Message ----- 
  From: Paul Ormandy ZL4PW 
  To: elecraft at mailman.qth.net 
  Sent: Sunday, January 02, 2011 4:22 PM
  Subject: [Elecraft] K3 losing RF power


  Hi all,

  More info...

  Was unaware of the power recommendations on 50MHz...

  I was running 100W calling CQ on 50MHz when the problem suddenly arose.
  Maybe running 100W on 6M has been the cause?

  If I dial up 100W on any band, RF power as indicated on the K3 display is
  70W.

  I am unable to get more than 70W on any band...

  And running very latest software 4.22.

  Cheers,

  Paul


  Hi all,
  >  
  >  My K3 has developed a problem...
  >  
  >  Power output is down to 70W and the LCD back-light flickers on tx. The

  "Low Voltage" message flicked

  > >  up briefly once.
  > >  
  > >  I suspect a DC power problem but so saying, the voltage at the rig is
  13.9V on transmit at 70W and

  > >  the rig is drawing 13A. The problem seems worse on the 6mb.
  > >  
  > >  If I reduce the output RF control to around 60W, there is no perceptible
  LCD flickering.

  > >  
  > >  I will obtain another 20A power supply tomorrow and see if the problem
  persists.

  > >  
  > >  In the mean time, (apart from running low power), can anyone suggest what
  I should start looking for

  > >  internally?
  > >  
  > >  Kind regards,
  > >  Paul
  -- 
  Paul Ormandy ZL4PW ZM4M
  www.radiodx.com
  www.zl4pw.orcon.net.nz

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