I have a common cathode, tetrode amplifier with mechanical tuning memories.
The way it is usually used is to tune it for the middle of the band (or in
the middle of a half of a band if the band is pretty big like 10m) with a
dummy load. Then to recall the memory and work on the entire band (or a
half) without manual tuning at all.
After a small incident of arcing in my DIY SWR meter at SWR of about 2.2 I
started wondering what is the amount of stress bad SWRs subjects all the
components to (cables, connectors and so on).
I've never saw any discussion of what is an acceptable "bad" SWR with a
tube amp. I suppose because it is relatively easy to adjust the tuning.
Except in case of this amp it might make more sense not to retune.
The amp is built like a tank (in fact people add another tube, or two
bigger tubes and run it at double or triple the power with no issues) so I
know the amp can take it. But all the other components that are sized for
1500W and a 50 ohm load like relays, connectors, cables and so on. These
are the things I'm worried about.(and when they smoke they might turn an
SWR of 2 into 20 which may end up damaging the amp).
So could someone please explain or point me towards some books/articles
that talk about what happens exactly with voltages/currents at bad SWR?
Many thanks,
Łukasz , SP4IT and SQ4KW
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