[Elecraft] Standalone K2 Amp?

[Don Wilhelm]

Tom and all,

If you remote both the KPA100 and the KAT100 --

In addition to the 'instructions' below, you may have to change L1 on 
the KIO2 AUX2 board (the one that plugs onto the control board) with a 
higher current choke.

With both the KPA100 and the KAT100 drawing current from the 12CTRL 
line, the sub-miniature choke does not have enough current capacity. 
Either the KPA100 or the KAT100 alone will be OK with the stock choke, 
but both together may cause the smoke to be released from the choke.

A small ferrite toroid core with 10 to 12 turns on it is a good solution 
- the inductance is not critical.  An FT23-43 like that used for the RF 
Chokes on the KSB2 board with 12 turns fits nicely.

73,
Don w3FPR

Don Wilhelm wrote:
> Tom,
> 
> I don't believe there are any explicit instructions - BUT -
> If you assemble the KAT100-2 and put it into an EC2 enclosure, the 
> mating of the KPA100 should be fairly obvious.  There is a header on the 
> KAT100-2 board to accept the ribbon cable from the KPA100, a 2 pin 
> header for the RF input connector and another 2 pin header for the DC 
> power. (BTW, Elecraft offers a kit to change the KAT100-1 to a KAT100-2 
> which includes the required headers).
> 
> For the external connections, you need only 3 - 1) DC power to the 
> KPA100 (the KAT100 receives its power from the internal cable from the 
> KPA100.  2) The control cable is just like that one shown in the manual 
> for the KAT100, and plugs in just like the normal KAT100 cable (that is 
> where the KIO2 is required in the QRP K2).  3) Use a short piece of coax 
> with BNC connectors between the QRP K2 (either the ANT OUT jack or with 
> the KAT2 installed, the ANT1 jack from the KAT2).  The other end of the 
> coax connects to the AUX RF input jack on the KAT100 rear panel.
> 
> That is all there is to it - set the menus just the same as if the 
> KPA100 was installed internally.
> 
> If the KPA100 is installed in the EC2 enclosure without the KAT100, the 
> situation is only a little different - one must install a BNC input jack 
> on the EC2 back panel and connect the KPA100 input coax to it (order the 
> mating header from Elecraft and solder it to the back of the BNC 
> connector for the easiest installation).  The control cable (just like 
> the one used with the KAT100) plugs between the KIO2 and the KPA100 AUX 
> I/O, and of course DC to the KPA100 rear panel power jack.  That is it, 
>  not really difficult at all.
> 
> 73,
> Don W3FPR
> 
> Tom Zeltwanger wrote:
>> Don,
>>
>> I now have all the pieces to do this (remote the KPA100 and KAT100-2). 
>> I have seen many discussions on this subject, and I know there are 
>> directions out there for doing this. Is there any one set of 
>> directions that is best in terms of describing all the steps? I don't 
>> necessarily need photos, but I need something that covers everything 
>> that needs to be done.
>>
>> 73,
>>
>> Tom KG3V
>>
>