Want to inform list members that as far as I
have been told by Vasco LZ1JK they have
made everything possible to fix the problem
with Jukka's PA and as soon as possible he
might be able to run full power again on 160m.
I know VP6BR problem , since I have had the
same problem myself with my ACOM few
months ago.
This happens when PA is run in very dusty
or wet environment. Some dust helps an arc
to form between the separation sheet which
separates the power supply board from RF
portion of the amplifier.
Distance there is more than enough (6mm)
but in dusty conditions high voltage arc
could be formed between the board and metal
separating sheet. ( in my case it was a long
hair - Hi, which helped this to happen).
Problem is solved within 20 min, if one
has some soldering experience to be able
to replace the resistor which in this case
is burned out ( the bang is heard) with the new one.
This problem in ACOM PA is currently solved
by covering the margin of the board with PTFE
and placing a filter over the hole at the rare of
the PA.
Otherwise ACOM PA is really fool proof - it
happened to me to use it by mistake without
any antenna ( Hi) during the last CQWW and
protection worked amazingly. Don't know if
any other PA would survive after such "test"
- Hi ?
Wally LZ2CJ
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