[Elecraft] KAT2 question abt voltage at U4, pin7

[KC9GBX]

After a recent calamity while attempting PSK31, where I introduced 13.5v  
into microphone jack pin 6 (a 5v line), repairs have been made, and I have made 
 
contacts in both cw and ssb modes.
 
However, I seem to be getting more HI CURRENT warnings on bands and at  power 
levels where previously, I did not.
 
I re-initialized the KAT2, and, as I cycle through L0-L8 and C0-C8, all  
relays provide a nice click.
 
I performed the dc voltage checks at the bottom of KAT2 manual, page  22.  
Everything was fine, except for U4, pin 7 where I got a reading of  4.74v 
instead of the 0v or nearly 0v that the manual implies I should see.   Could 
this be 
the cause of the HI CURRENT warnings?
 
Thanks for your  consideration.   
 73,  Jef Fox kc9gbx
**Great Deals on Dell Laptops. Starting at $499. 
(http://pr.atwola.com/promoclk/10075x1217883258x1201191827/aol?redir=http://ad.doubleclick.
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Re: [Elecraft] KAT2 question abt voltage at U4, pin7

[Don Wilhelm]

Check the actual power with an external wattmeter - set the power 
control to 5 watts and transmit, then tell us if the actual power is 
near 5 watts or near the maximum power (12 watts or over).

It is possible that U4 is faulty.  Pin 7 is not used - there are 2 op 
amps in the LM358 package, so if the one having its output at pin 1 is 
OK, power will be controlled and it does not matter what pin 7 does 
because it is connected to nothing.  The power output check above will 
tell if the output at U4 pin 1 is working.

73,
Don W3FPR


kc9...@aol.com wrote:
 After a recent calamity while attempting PSK31, where I introduced 
 13.5v into microphone jack pin 6 (a 5v line), repairs have been made, 
 and I have made contacts in both cw and ssb modes.
  
 However, I seem to be getting more HI CURRENT warnings on bands and at 
 power levels where previously, I did not.
  
 I re-initialized the KAT2, and, as I cycle through L0-L8 and C0-C8, 
 all relays provide a nice click.
  
 I performed the dc voltage checks at the bottom of KAT2 manual, page 
 22.  Everything was fine, except for U4, pin 7 where I got a reading 
 of 4.74v instead of the 0v or nearly 0v that the manual implies I 
 should see.  Could this be the cause of the HI CURRENT warnings?
  
 Thanks for your 
 consideration.73, 
 Jef Fox kc9gbx

 
 Great Deals on Dell Laptops. Starting at $499. 
 http://pr.atwola.com/promoclk/10075x1217883258x1201191827/aol?redir=http://ad.doubleclick.net/clk;211531132;33070124;e
  

 

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