[Elecraft] Driving (big) linear amps with the K2?

[phoon.usinet]

Has anyone used the K2 either barefoot, or with the KPA100 "cover top"
amplifier to drive a linear amplifier (Alpha, QRO, etc)?

I am considering the K2 for backpacking and emergency use, and the K2
combined with the QRO HF 2500 linear for home station emergency and mountain
states high noon net QRO operation.  Forest fire dangers are high this
summer in Colorado, and I live in an isolated mountain community.

I have not been able to find the required information about the K2 keyer
output at the K2 website.

The QRO  HF 2500 linear amp can put out healthy RF with surprisingly low
drive levels, as low as 5, 10 or 15 watts (1000 watts out with 20 watts of
drive on 40 - 80 meters).  Whether the KPA100 is necessary to drive the QRO
HF 2500 Linear, is open to debate.

In addition to RF drive, the QRO HF 2500 amplifier requires keying output
from the K2 transmitter, in a shielded audio cable connection, in one of two
possible ways:

Key XMT:  Relay contacts of xmtr must be open during receive, closed during
transmit, and must "sink" +12VDC to ground at 80 MA for CW.

OR:

+15V XMT:  Xmtr has a provision for +15VDC on xmt for keying external
devices such as linears.

1)  Does the keyer circuit of the K2 have such a capability?  I know that
the K2 has diode switching, but can it handle 80 Ma?

Is there an external "keyer out" jack on the back of the K2 with a phono
female jack?

2)  I assume that if the above keyer out put connection to the QRO HF 2500
can be made, that VOX SSB operation from the K2 to the vacuum QSK relay
inside the QRO HF 2500 is also doable. Comments welcomed on this point.

3)  The power output of the K2 is 12 to 15 watts "barefoot".  Has anyone
been able to increase the output to 20 or even 30 watts, perhaps by changing
the final amplifier transistors, and/or their biasing?  Or, by altering the
driver circuit that drives the final transistors?  That is, with out the
KPA100 "cover top" amplifier?

The idea here is that with a few mods to boost the K2 output up a bit, to 20
 or maybe even 30 watts, the  KPA100 would not be required to drive the HRO
2500 linear amplifier.

Any ideas, comments, pertaining to driving (big) linear amps with the K2
would be appreciated.

Thank You,

Peter
VE1CHS Lifetime Canadian Certificate
In Nederland, Colorado
phoon@attglobal.net