Elecraft 100w Amp

When I purchased my Elecraft K3/10 in late 2008 I pretty much made up my mind to operate QRP and keep the rig at a maximum of 10 watts. Now nearly three years later with 135 countries confirmed on 5 and 10 watts, I began to realize that if I wanted to work more countries I’d either need to add a tower and beam antenna or the Elecraft built-in 100 watt amplifier.

I looked closely at building a tower and have certainly scoped out some beam antennas. I also use a 15 meter Moxon on a temporary basis for contests. However, it has become clear that my yard won’t support a tower and beam, nor are we going to move to a new location any time soon.

The deciding factor in purchasing the 100 watt amplifier was reading W9KNI’s book The Complete DXer. In the book, Bob Locher states that one way or another you really need 100 watts ERP (effective radiated power) to get into the higher DX levels. He stated this particularly about working 80 and 40 meters. That was the moment I knew that I’d need to add the 100 watt amplifier.

This past week the amplifier arrived (under the guise of a Father’s Day gift). I had also looked at the various Elecraft hardware updates to install at the same time the case was off the unit. I found the Low Pass Filter that needs to be installed on the DSP board. This was the most challenging aspect of my kit building this weekend. I needed to take the front panel off and remove the DSP board. Then I needed to solder six wires onto the DSP board and mount the small low pass filter board. You can see this in the photo gallery below. It worked reasonably well. The price was $40 rather than swapping a board with Elecraft for $110. It turned out to be a smart move.

The KPA3 100 amplifier installed very nicely. I did confuse myself a few times when I turned the page of the assembly manual, skipping a page in the proces. Caught the error both times with no adverse effects. Then I moved to the calibration routines that were very straight forward using the K3 utility on my iMac which stepped through the routine. All is working well as demonstrated by a nice CW QSO with LU5OM in Argentina, right after I got all the cables installed once again.

I’m delighted with the K3. I’ve been able to add capabilities over the years as I’ve saved the money and as my operating needs/wants have changed. Plus, I’ve still got a very small footprint in my ham shack — everything’s installed inside the K3. I’ll also note that the firmware has been updated at least a dozen times over those three years — each time enhancing my rig and my operating fun!

KPA3 Installed with shield, boards, and fans

KPA3 Installed with shield, boards, and fans

KPA3 100 watt amplifier board

KPA3 100 watt amplifier board

Close up of KPA3

Close up of KPA3

K3 ready for KPA3 installation

K3 ready for KPA3 installation

Installed Low Pass Filter on DSP board

Installed Low Pass Filter on DSP board

Low Pass Filter on DSP board

Low Pass Filter on DSP board

What do you think?