Today, after completing a few chores, I finally got a chance to assemble my KXPA100. For the record, I did not pre-download the assembly or instruction manuals. Maybe I should have, but I didn't. I decided to just wing it and go with the flow after opening the box.
A few guys on the KX3 e-mail reflector claimed an assembly time of two hours. I completed mine in just a little over one hour. Basically, all you're doing is securing the autotuner board to the amplifier, and then putting the housing on. Not much work, easy as pie to do, and you end up saving a couple hundred dollars.
I learned a few things the hard way:
1) Don't assume you have the latest firmware in your KX3 just because you normally upgrade often. I thought I had the latest version, only to discover I didn't. When I couldn't get my KX3 to go above the 12 Watt level, I knew something was wrong. A firmware update took care of that.
2) Keep the KXPA tuned "off". Sounds strange, doesn't it? There is an "On/Off" switch on the KXPA100, but it is meant for when you are using the amp with a radio other than a KX3. If you use a KX3, it totally controls the amp. Turning on the KX3 turns on the KXPA100. Turning off the KX3 turns off the KXPA100. If you have the "On/Off" switch turned on while using the KXPA100 with a KX3, the LED indicators don't work properly. You may set the KX3 for, say 75 Watts - but the LED indicators won't light up properly. Turnng the switch off remedies that.
Item 1 was prominently mentioned in the manual. I had assumed something, and you know what happens when you assume. I didn't see anything about the "On/Off" switch in the manual, but admittedly, I glossed through it and did not read it as carefully as I should have - again, my fault.
It is working properly, and I did give it a trial run my making some ARRL DX Contest QSOs at higher power just because I could - not because I needed to. I think in most cases, QRP would have worked. Tomorrow, however, I want to take the amp on a "shake down cruise" and really give it a go - just to see how these boots feel and break them in a bit.
Not that I am abandoning QRP - by no means. For 95 to 99% of the time, my KX3 will continue to purr along at the 5 Watt or less level. But having this amp sure would have been handy a week ago for adding FT5ZM to my log. I'm enough of a DXer to regret having missed that opportunity.
73 de Larry W2LJ
QRP - When you care to send the very least!