I have a relatively new Alpha 9500 that clearly is experiencing some
problems:
1) Last weekend I keyed up the rig on 20 m and noticed the power and
grid current LEDs were pegged in the red. The amp immediately faulted with
fault 15 (excessive grid current).
2) This behavior was repeatable and persisted even after I powered down
and then back on.
3) I also had one or two fault 8's when I tried exercising the band
switch.
4) I also saw that the tube was getting hot so I powered down and sent
a message to RF Concepts.
5) They asked me to check to see if the grid current problem persisted
even with no RF drive - it does.
6) When performing these second tests (Thursday) I noticed that the amp
would draw current (about 125 mA) when in the operate mode even when not
keyed up.
7) Finally, last night and this morning I noticed that when the amp is
warming up and I go to Operate mode (flashing green) the tube would start to
draw current (starts at 30 mA and then to 125 mA) as it warms up. Also the
tube was getting very hot (even with blower on).
I suspect a problem with grid voltage supply. However, does anyone else
have ideas?
I have several calls into RF Concepts but they haven't responded yet.
BTW, the amp is only about a year old. I baby it.never hot switch between
bands and it only gets about 8 hours of operating time per week.
Thanks for reading.
73, Jeff
W3KL
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