[Elecraft] High Power PA Option vs. Auto-Tuner and Battery Options

[Mark J. Dulcey]

Kirby Davis wrote:

 
> 1. Rather than get the PA option and forfeit the other two options, would
> another option be to get an amplifier to up the power of the base K2 and keep
> the other two options? Or, does the 20W limit on the auto antenna tuner
> prevent the use of an amplifier on a base K2?


The catch is that such an amplifier can't legally be sold in the US. If 
it weren't for that little complication, your plan would work just fine. 
Tokyo Hy-Power makes a nice line of QRP-capable HF amplifiers, if you're 
willing to go abroad to buy one.

The 20W limit of the auto-tuner would have no effect on amplifier use, 
since the tuner would be before the amp. Of course, it would also have 
no effect on antenna tuning in that setup; if you wanted both high power 
and automatic tuning, you'd need a higher-power tuner to follow the amp, 
or an amp with a built-in tuner (if such a thing exists).

Elecraft has talked about a higher-power tuner as a companion piece for 
the KPA100. It's not an announced product, though, so it may or may not 
happen.

 
> 2. Any other comments/assistance regarding the pros/cons of the various
> options (including "purchase them and build them now when your building the
> base K2" vs "its just as simple to build and install them later to the base
> K2" suggestions) would be greatly appreciated!

Whether or not you buy the options right away, you should certainly 
build and test the base rig first. If you have the options on hand right 
off, you can install some of the connectors during the initial build 
(the instructions tell you which ones and where they go), saving a bit 
of disassembly later.

When you later install the options, you do have to remove a few jumpers 
and components from the K2 circuit boards, which can be a pain. An 
alternative is to build the "un-modules" that I designed 
(http://mail.buttery.org/mark/unmodule/); they let you build the rig 
without the modules (but with the connectors), and later add the modules 
without any main board rework.