Hello to the group.
Thanks to all of the fine pictures and discussions on C tubes it has me
thinking a lot about what actually happens in a mighty old tube.
We always assume the tube has used up the Cesium as to why there is no beam
current. The dead tube answer.
But because of all the details shared recently I am starting to question
that answer.
I do wonder about the internal state magnets. As old as these are they most
likely loose the strength they started with. As such the separation of the
Cesium atoms in each state selector becomes less over time.
The bad Cesium ions may actually be missing the getter targets at each end
of the tube and moving towards the main beam.
The effect increased noise as more and more of the wrong C's hit the
ionizer.
Why would I think this?
Because as a ham I recovered numbers of Travelling Wave Tubes (TWT) by
moving magnets around the tube to refocus the beam and essentially stop
helix overloads.This was a standard trick hams that used TWTs knew about. A
TWT is very much like a CBT.
The placement was different on every tube because as the magnet performance
declined which magnet was the issue. There could be several magnets.
Kind of a strange test would be to find a weak tube or bad.
turn off any frequency locking.
Somehow remove shields Skip knows how to do that and try it out.
Or is it even possible for a strong magnet to get through the shields as is
and influence the state selectors????? A really simple experiment.
Might need to order a strong magnet from ebay.
Thanks
Paul
WB8TSL
Hello to the group.
Thanks to all of the fine pictures and discussions on C tubes it has me
thinking a lot about what actually happens in a mighty old tube.
We always assume the tube has used up the Cesium as to why there is no beam
current. The dead tube answer.
But because of all the details shared recently I am starting to question
that answer.
I do wonder about the internal state magnets. As old as these are they most
likely loose the strength they started with. As such the separation of the
Cesium atoms in each state selector becomes less over time.
The bad Cesium ions may actually be missing the getter targets at each end
of the tube and moving towards the main beam.
The effect increased noise as more and more of the wrong C's hit the
ionizer.
Why would I think this?
Because as a ham I recovered numbers of Travelling Wave Tubes (TWT) by
moving magnets around the tube to refocus the beam and essentially stop
helix overloads.This was a standard trick hams that used TWTs knew about. A
TWT is very much like a CBT.
The placement was different on every tube because as the magnet performance
declined which magnet was the issue. There could be several magnets.
Kind of a strange test would be to find a weak tube or bad.
turn off any frequency locking.
Somehow remove shields Skip knows how to do that and try it out.
Or is it even possible for a strong magnet to get through the shields as is
and influence the state selectors????? A really simple experiment.
Might need to order a strong magnet from ebay.
Thanks
Paul
WB8TSL
