K2SB and HI CURRENT

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K2SB and HI CURRENT

Tom Cleveland


I have been using my K2 Barefoot(Sn 4065)  for a few years as CW only and love the radio. I recently assembled the KSB2 adapter
and have a problem. When transmitting at any power level setting either CW or SSB I get a  HI CURRENT warning and the output folds back.

I checked a few signals and found that the ALC line was shorted to ground. After poking around i found that if i lifted pin 2 of
U1 the Hi Current went away , and that PIN 2 of this chip is indeed shorted to ground internally. Rather than assume this is the
only issue, wonder if i can get any suggestions on likelihood of a bad MCU, vs other causes.

I have checked out D1 D2 and Q1 and all are okay, and the Cap is removed from the RF board.
Re-examined all the solder connections and part orientations. Other thoughts would be appreciated.

Thanks
Tom '3RSA
     
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Re: K2SB and HI CURRENT

Don Wilhelm-4
Tom,

Yes, you will get HiCur messages if KSB2 U1 pin 2 is shorted, and there
will not be sufficient control over power output.

It certainly sounds like that KSB2 firmware IC input pin is toast.  If
there was any static gathered when you were inserting the IC, that is
probably when it happened.  Handle the replacement one with good
anti-static measures.

73,
Don W3FPR

On 3/7/2012 12:34 PM, Tom Cleveland wrote:

>
> I have been using my K2 Barefoot(Sn 4065)  for a few years as CW only and love the radio. I recently assembled the KSB2 adapter
> and have a problem. When transmitting at any power level setting either CW or SSB I get a  HI CURRENT warning and the output folds back.
>
> I checked a few signals and found that the ALC line was shorted to ground. After poking around i found that if i lifted pin 2 of
> U1 the Hi Current went away , and that PIN 2 of this chip is indeed shorted to ground internally. Rather than assume this is the
> only issue, wonder if i can get any suggestions on likelihood of a bad MCU, vs other causes.
>
> I have checked out D1 D2 and Q1 and all are okay, and the Cap is removed from the RF board.
> Re-examined all the solder connections and part orientations. Other thoughts would be appreciated.
>
>
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Please help support this email list: http://www.qsl.net/donate.html