[Elecraft] linear amp shutdown (was ALC)

[Geoffrey Mackenzie-Kennedy]

 From: David Cutter G3UNA

> I take your point entirely which is why I said
>
> "ALC is an analog signal for gradually reducing drive, which
> might not be appropriate for shutdown."
>
> Shutdown for me is for protection against gross overload and for this 
> another signal might be more appropriate.  Since many users do not connect 
> ALC, some other signal for protection should/could be provided.  The 
> problem yet again is that users might still ignore what the manufacturer 
> offers, so, the amplifier must protect itself.

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David,

It has always been my understanding that normal and good practice is for a 
shutdown system to actually *shutdown* the entire transmitter affected in 
the event of gross overload / failure, e.g. *abnormal* VSWR, cooling system 
failure etc.  A system which protects the amplifier only could still result 
in damage to the exciter / driver under some circumstances of gross overload 
/ failure, for example when using my K2/100 a while back during some contest 
wind toppled a large pine across the antenna in use, the KAT100 sparkled and 
both the KPA100 and K2 were damaged. My K2/100 is now protected by the total 
shutdown system used with my other rigs, something that I should have done 
before ever using the K2/100 at this location.

I take your point that the amplifier should be able to protect itself  if 
people ignore what is offered.

73,
Geoff
GM4ESD

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