[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


KC9GBX at 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
>
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