[Elecraft] Erratic Power Problem after replacing PA transistors

[Raven, Timothy]

Hi there K2ers


I have just rebuilt the PA on my K2 using the K2PAKT, after one of the
devices failed and started drawing current on RX.

This has now cured the high current on receive, but I think I might have a
problem in the KAT2.

After switching back on, and pressing the Tune button, I noticed that the
tune power was not 3 watts, but over 10 watts with the Hi Current warning. 

The power control was also very erratic, and seemed to  jump from 0.2 of a
watt to 8 or 9 watts, and the KAT2 in auto mode couldn't match my 80 Metre
Dipole, which has a 1.2:1 SWR. 

The problem still occurs using a 50 Ohm dummy load and is also the same via
the 2nd Antenna socket

The Cal n, displayed HI, and the power was way over the 5 watts I set it
too.

I checked all the voltages on RX on the ICs in the KAT2, and they are OK.
Also the KAT2 commands work via the menu options.

If I disconnect the KAT2, the Power Control works fine, and gives out very
close to what I set it too, and I don't get any Hi Cur messages

I now wonder if the KAT2 has failed and that's what killed my PA, or was it
the other way round?. When the PA failed I heard relay noises from the KAT2,
but assumed that this was as a result of the PA impedance changing when the
PA failed

The RX side appears to be unaffected.

Any help would be greatly appreciated


73 Tim G4ARI  (QGRP 7809)



=======================================================
This message contains information that may be privileged or confidential and is the property of the Cap Gemini Ernst & Young Group. It is intended only for the person to whom it is addressed. If you are not the intended recipient, youare not authorized to read, print, retain, copy, disseminate, distribute, or use this message or any part thereof. If you receive this message in error, please notify the sender immediately and delete all copies of this message.
=======================================================