[Elecraft] K2 VCO Problem

[walter renner]

Hi I am new to the list, but I am having a heat related problem with my =
K2 serial # 3511 when I added the KPA100. With With PA installed on the =
K2 case, and just used on receive  for several hours or so, if the K2 is =
switched for the lower bands (160, 80, 40) to higher band 30m and above =
and then returned to  40, 80, or 160, the VCO will not start up. You can =
return to band higher than 40 m, and the VCO  will operate fine. This =
all happens with a heat sink temp. of 23 degrees C, and if the K2 is  =
shut off the heat sink temp must drop to at lest 21 degrees C for the =
VCO to start up again on the 40, 80, 160 m bands.
With the PA removed from the K2 the VCO works fine. I am monitoring the =
VCO voltage at R30 on the RF board when this happens.=20
This relates to a temp of only about 72 degrees F, and I have tried =
using a heat gun to blow hot on the VCO area on the RF board with =
limited success in producing the the same results. Have not found a way =
to raise the temp of individual components yet.
Any ideas on what components are related to the 160, 80, and 40m bands =
that could be producing this condition?
Kurt K0ARO

--- StripMime Report -- processed MIME parts ---
multipart/alternative
  text/plain (text body -- kept)
  text/html
The reason this message is shown is because the post was in HTML
or had an attachment.  Attachments are not allowed.  To learn how
to post in Plain-Text go to: http://www.expita.com/nomime.html  ---