[Elecraft] K3 Keying Up For A Split Second When Power Button, IsPushed (Tom W8JI)

[Art K6XT]

It is not normal behavior for my K3. The red tx light comes on for a 
split second but there is no amp keying or RF output.
73 Art

-- 
73 Art
Allison, Colorado
"Whether you believe you can do a thing or
not, you are right."  --Henry Ford.

Message: 51
Date: Thu, 1 Apr 2010 07:50:22 -0400
From: "Tom W8JI" <w8ji at w8ji.com>
Subject: Re: [Elecraft] K3 Keying Up For A Split Second When Power
	Button	IsPushed
To: "-.-.  --.-N3TU -.-.  --.-" <connectmenow at hotmail.com>,
	<elecraft at mailman.qth.net>
Message-ID: <B545DB30C1794028B301FBF152F950A0 at radioroom>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
	reply-type=original

<<<Is it normal for the K3 to key up right away for a split 
second when turned
on. I have a Drake L4B with a soft key behind the radio. If 
by accident the
amp is out of the  stand-by mode and you turn on the K3, it 
will key the amp
for a split second. Is this normal? Don't get me wrong, I 
try to put it in
standby but every now and then I'll forget. >>>

That's normal behavior for the K3.

I don't like it either, but a properly designed step-start 
should still be OK with just the quiescent current of the PA 
tubes so long as RF is not applied. The only problem would 
come in when the step-start and the radio both have issues. 
If the step-start isn't planned well, and blows a fuse or a 
resistor when starting under quiescent current loads, then 
the radio doing closing the relay line at power-on  becomes 
a problem.

As a suggestion you could easily build a time-delay start up 
for the amp, which it should have if simply closing the 
relay control line at amplifier power-on causes damage. 
You'd have to add a small relay and wire it in series with 
the relay control jack.

My amplifiers start just fine at quiescent loads, so I don't 
worry (although what you observe annoys me too and I can see 
where it could cause step-start damage in some systems).

73, Tom