Before the KPA100 came out I experimented with the K2 to see if I could get more output to
drive an external amplifier.
There IS a way, but I am sure there are lots of dangers involved. I will say that I did
this for a month or so until I got my KPA100. I am not recommending it!
The K2 has a closed-loop power control circuit. The MCU looks at the amount of power being
produced and adjusts the drive to increase or decrease it until it matches the setting of
the POWER control.
So if you lie to the MCU and tell it that less power is coming out than actually is, it
will increase the drive to try to make it reach the set point.
I have a KAT2 so all I had to do was adjust the forward power pot to say that there was
less output. I believe I got about 22 watts on 40 meters this way (less on other bands).
Again, you are undoubtedly stressing things beyond design limits when you do this and bad
things could happen. It might be better to get an external amplifier like the HF Packers use.
On 9/26/2013 5:55 AM, Allan Taylor wrote:
I have a very early K2 that I use for field operations. It functions as an
emergency communication source for serious
backcountry trips (multi-day wilderness whitewater rafting, etc.). I am
finding that a power output of, say, 20W would be
desirable as a compromise between more reliable communication and battery
usage. My K2 puts out about 14W. Thus I
ask the experts: has anyone revamped the TX RF stages sufficient to put out
20 -25W output? Yes, I know this amounts
to only a dB or two. But it can be the edge needed in very marginal
conditions.
Second issue. The K2 has always been on the low side for RX audio. Being no
longer a young buck, my hearing is not
perfect any more. Is there a known mod to add 5-10 dB to the audio chain
without drastic distortion? Presently I take along
a Radio Shack headphone 3-way amp that gives about that. It works fine but
is yet another piece of gear to bring along and
doesn't feed the internal speaker. When I had a KX1 (now sold) it had been
modified to have a second audio amp chip put
in and it really helped. Has anyone done a similar thing for the K2? I am
not a EE by any means so would prefer to follow
known modification paths.
Anyone?
--
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco/
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