[Elecraft] linear amp shutdown (was ALC)

[N2TK]

David,
I hope when Elecraft comes out with their amp that it has features like my
Acom 2000A - if there is an arc, high swr or overdriven the amp shuts down
quickly without damage to it. When this happens I can quickly check to see
if I am on the wrong antenna, too much drive or a problem with an
antenna/feedline. When this happens I am still able to run barefoot.

With most of my rigs over the years I have used a power mosfet to key the
amp. With the Kenwoods and Icoms I have bypassed their amp keying relay to
pick up a quicker transmit-on signal from the rig. This way I have a better
chance of the amp's relay pulled in before RF gets to the amp. Some rigs put
out an RF spike at key-down. This causes the amp to kick out. None of the
rigs I have had so far have had this problem. I don't use the mosfet keying
with my K2 since it really doesn't have fast QSK. Hopefully the K3 will have
QSK as good as the TS-930 and TS-940.

73,
N2TK, Tony

-----Original Message-----
From: elecraft-bounces at mailman.qth.net
[mailto:elecraft-bounces at mailman.qth.net] On Behalf Of David Cutter
Sent: Tuesday, December 04, 2007 8:33 AM
To: Geoffrey Mackenzie-Kennedy
Cc: Elecraft Discussion List
Subject: Re: [Elecraft] linear amp shutdown (was ALC)

Geoff

With so many combinations of rig and amplifier a 'standard' would be good, 
(the Collins ALC started it all I understand) but in its absence each 
operator needs to make provision for their own station protection.

With the advent of solid state amplifiers there was a chance to make a new 
standard to help us all, perhaps someone knows if this was taken up .  It 
would be good to know how folks have covered themselves with various 
rig/amplifier combinations and  I wonder how the Elecraft linears will do 
this.  I see the SPE linear has 3 stages of protection for instance: SIMPLE 
= audible alarm, SERIOUS = switch to standby and FATAL = complete shutdown, 
but these do not shutdown the driving transmitter as far as I can see. 
After all, running barefoot is better than nothing in a contest, so, 
shutting down the transmitter is not always desirable.

David
G3UNA