[Elecraft] Bad start to FD - smoked a K3!!!!

[Brett Howard]

You may look into checking Q8 and Q9 in the post amplifier.  You can see
what I'm talking about in the top right section of page 8 on the
schematics (here):
http://www.elecraft.com/manual/K3_Schematics_Jun_2010.pdf

Also check the resistors around that area for stuff that looks like it
got hot...  R66, R68, R56, R75 and the like...

I had something similar happen to me and Q9 blew on my radio.  Replace
Q8 and Q9 together if its needed as well as any of the resistors that
had a hard day and you should be ok...

The K3 does have protection for this if you have the mod in place that
helps make it happen.  The current through this path is monitored and if
the power in gets too high it can turn off your preamp or engage the ATT
to try and protect itself.  However when running high power with
multiple stations in close proximity there are procedures and equipment
that should be in place or you're going to have problems no matter what
brand of radio you're running.

~Brett (N7MG)

On Sat, 2010-06-26 at 06:06 -0700, NZ0T wrote:
> We had one guy get on 75 with a KW with another on 40.  Guy on 40 didn't
> know.  He got the RFI warning, the K3 locked up and he smelled smoke.  Now
> his K3 has no RX at all.  I thought there was a high power protection
> circuit?  We have other rigs to use but any input as to what needs to be
> done with the smoked K3 would be appreciated before he sends it back to
> Aptos.
> 
> 73 Bill NZ0T  My K3 is OK