[Elecraft] K3 SO2R Question

[Brett Howard]

http://www.elecraft.com/K3/mods/K3%20rx%20protection%20mod,%20rev%20B.pdf

That document explains a mod that you should definitely make sure is
in place in your radio if you're worried about this condition.  I had
one of Q8 and Q9 blow in my radio after too much power came back in
from another operator who told me he *WAS* staying off of 20 meter
like to told him to do he was down on 14 meters!  ;)  Anyway we
replaced the Q and the rig came back to life.  But if you view that
document it says that when you get to +13 to +20dBm it will
automatically engage the preamp for you.  +20dBm is 100mW so that
would at least give you an added 10dB of protection on your way up to
the 1-2W realm.

~Brett (KC7OTG)

On Mon, Mar 8, 2010 at 2:03 PM, Jim Harris <w0em at q.com> wrote:
>
> Hi Folks,
>
> I'm currently selling an off-shore rig with the hopes of acquiring a second K3 for SO2R, primarily for RTTY contesting.  I believe I've seen somewhere in the not to distant past that is was said the K3 receive front end can withstand 1-2 watts without damage.  I've spent the last hour reviewing the email archive and can find no reference to that.  Can anyone confirm or deny my remembrance?  (Or, is it all just wishful thinking?)  Is there anyone on the reflector that is operating a K3 SO2R station without the thousand or so dollars of band pass filters needed to protect the radio's front end?
>
> Second part of the question is.....if possible to not damage the front end, what is the possibility of desensing or causing blocking or noise that would interfere with reception on one receiver when transmitting on the other radio.  I'm sure that is highly dependent on band(s) and separation of frequencies within the band.  I'll fully aware of the K3's ability to completely block signals a few kilohertz away but when RTTY contesting I do seem to notice there may be some desensing or AGC action from these signals even though they are not heard or processed by MMTTY.
>
> Comments very much appreciated.
>
> CU in the Colorado QSO Party Sept 4th, 2010.
>
> 73,  Jim, W0EM
>
>
>
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