[Elecraft] Keying A Small Amp With A K2

[David Yarnes]

Hi All,

I haven't been paying much attention to the conversation 
here about keying amps, etc. since I rarely use one. 
However, a situation has arisen which suggests I should have 
paid closer attention.

I have a couple of small amps--an HL50B, and an HLA-150, 
that work well with QRP rigs for a little extra boost.  The 
HL50B works best with the K2 (and other QRP rigs) as it has 
good RF sensing, and keys right up when you hit the paddle. 
The HLA-150, however, doesn't do quite as well.  It 
supposedly has RF sensing too, as well as auto band 
switching, but on CW I find that it is just a tad slow in 
triggering.  Accordingly, it tends to cut off the first 
"dit" or "dah".  That's about the only complaint I have 
about it though.  With less than 10 watts of drive you can 
get over 100 watts out.  The auto bandswitching works very 
well.  The HL-50B puts out about 60 watts with 5 watts of 
drive.

The HLA-150 has a keying line input jack for direct 
connection to a transceiver.  However, the K2 doesn't have a 
keying line output that I'm aware of.  So, my question to 
you amp gurus is what would be the best (easiest) way to 
make this work?  I'd take my HL-50B, but I left it up in 
Oregon with my motorhome.  I'll rectify that mistake the 
next time I get up to Oregon.

Any suggestions?

Dave W7AQK