[Elecraft] [K2] Installing old KPA100 in a 2nd K2?

[Don Wilhelm]

Steve,

Both those K2s have the latest changes, so there should be no need to 
add C224 (it is already there).  Likewise the Control Board C42.
Firmware 2.40P is the next to the latest, and differs from 2.04r in that 
2.04r eliminates the selection of the sidetone source and 'glues' it to 
U8-4.  That eliminates many customer service calls because "my K2 has 
lost its sidetone".

You should only have to install the AUX RF and AUX 12V headers and 
remove Control Board P4 pin 4 to install the KPA100 - as well as scrape 
the paint from the side panels so the shield clips provide a good ground.

Any K2 above SN 4660 is the latest version, and the only thing missing 
from SN 4509 is the K2 Keying Waveshape Mod which is no longer available 
because the glass PIN diode to be used at D36 on the RF board is no 
longer available.
If you want to know how to add the K2 Keying Waveshape Mod to your K2 SN 
4509, please send me an email off-list and I can fill you in with the 
details.

You should check that used KPA100 to see if it has the latest updates.  
If it has blue core toroids at RFC1 and L16, then it is up to date, but 
if not, I highly recommend adding KPA100UPKT to bring it up to date.  
The shield should have clips to ground the shield to the K2 side panels 
and also have a narrow slot above the SO-239 jack with solder lugs 
connecting the outer surface of the shield to the SO-239.  In addition, 
it should have a shield over the speaker magnet.  The KPA100SHLDKT 
should be added if any of those conditions are not true.

The CAL TPA calibration is stored in the K2 EEPROM, so you will have to 
set it in the new K2.  The PA ON menu must also be set as well as CAL 
CUR and the 8R menu parameter should be set to HOLD.

73,
Don W3FPR


On 2/25/2015 10:47 AM, Steve Kavanagh wrote:
> I have recently acquired a used K2, my 2nd (S/N 5133).  I am just wondering what it would take to install the KPA100 from my older (S/N 4509) K2 in the newer one and keep it usable with the old one too.   I have been perusing the KPA100 manual (current version) and it appears to me that all I need to know is on pages 23-25 and 55.  S/N 5133 is missing the Aux RF plug P6 on the RF board and (I think) the associated C224, so those need to be added.  The manual which came with it says CNTL-C42 is already 0.1 uF (to be confirmed) and the MCU firmware is 2.04P.  The tasks on page 59 do not apply since the S/N is over 3000.  So it looks like all I have to do once RF-P6 and C224 are in place is to break off pin 4 on CNTL-P4, scrape off some paint and plug in the KPA100.  Am I missing anything ?  No alignment steps which might make it incompatible with the older K2?  What about CAL tPA (p. 49 of KPA100 manual)?  Is this calibration stored in the K2 or the KPA100? 73,Steve VE3SMA
>