KPA100 Tightening the finals...

[Ward Willats-3]

Just finished the KNB2 for my K2 (a birthday present from the in-laws
-- yea!) and while I was inside the K2 to install it I tightened up
the screws on the KPA100 finals per Elecraft's recommendation, since
I've been using the radio for about 6 months now and this was
probably overdue. They all took a little snugging up, maybe a little
less than 1/8 turn.

My question is: will they stay tight now for all time? Or do I have
to check them now and then? What's the theory on the thermal cycling
here and how it effects these screws?

Just wondering...

-- Ward / KG6HAF
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[Ron D'Eau Claire-2]

I haven't noticed any looseness in mine since tightening them a few months
after the initial build, and I did some testing of the "drift" mods that had
me cycling the K2 finals over and over again hard enough that the heat sink
was too hot to leave my hand on for any length of time.

So I'd guess that you're fine, now that you've done the initial
re-tightening.

Checking heat sink screws whenever I have a rig open is sort of "second
nature" to me after servicing gear professionally for a few years. On the
other hand, you don't want to crank 'em down so tight you damage the gaskets
and washers on the hardware. Snug 'em but don't do what I like to call
"Godzilla" them <G>.

Ron AC7AC

-----Original Message-----

Subject: [Elecraft] KPA100 Tightening the finals...


Just finished the KNB2 for my K2 (a birthday present from the in-laws
-- yea!) and while I was inside the K2 to install it I tightened up
the screws on the KPA100 finals per Elecraft's recommendation, since
I've been using the radio for about 6 months now and this was
probably overdue. They all took a little snugging up, maybe a little
less than 1/8 turn.

My question is: will they stay tight now for all time? Or do I have
to check them now and then? What's the theory on the thermal cycling
here and how it effects these screws?

Just wondering...

-- Ward / KG6HAF _______________________________________________


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[johnny-52]

I share the same experience as Ron.

73

Johnny Siu VR2XMC
----- Original Message -----
From: "Ron D'Eau Claire" <[hidden email]>
To: <[hidden email]>
Sent: Monday, July 05, 2004 9:29 AM
Subject: RE: [Elecraft] KPA100 Tightening the finals...


I haven't noticed any looseness in mine since tightening them a few months
after the initial build, and I did some testing of the "drift" mods that had
me cycling the K2 finals over and over again hard enough that the heat sink
was too hot to leave my hand on for any length of time.

So I'd guess that you're fine, now that you've done the initial
re-tightening.

Checking heat sink screws whenever I have a rig open is sort of "second
nature" to me after servicing gear professionally for a few years. On the
other hand, you don't want to crank 'em down so tight you damage the gaskets
and washers on the hardware. Snug 'em but don't do what I like to call
"Godzilla" them <G>.

Ron AC7AC

-----Original Message-----

Subject: [Elecraft] KPA100 Tightening the finals...


Just finished the KNB2 for my K2 (a birthday present from the in-laws
-- yea!) and while I was inside the K2 to install it I tightened up
the screws on the KPA100 finals per Elecraft's recommendation, since
I've been using the radio for about 6 months now and this was
probably overdue. They all took a little snugging up, maybe a little
less than 1/8 turn.

My question is: will they stay tight now for all time? Or do I have
to check them now and then? What's the theory on the thermal cycling
here and how it effects these screws?

Just wondering...

-- Ward / KG6HAF _______________________________________________


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[Don Wilhelm-2]

The initial re-tightening seems to be all that is required.
I believe the thermal pads will slightly thinner after an initial period of
being exposed to the pressure from the initial tightening and that normal
'squeezing' process may be shortened by the thermal cycling.  I have not
been able to torque my KPA100 screws any significant amount after the first
re-tightening (the first time WAS significant).

If my theory is correct - anytime the thermal pads are replaced, one should
do the re-tightening just as on a new KPA100.

73,
Don W3FPR

Life is what happens when you are making other plans

> ----- Original Message -----
>
> I haven't noticed any looseness in mine since tightening them a few months
> after the initial build, and I did some testing of the "drift" mods that
had
> me cycling the K2 finals over and over again hard enough that the heat
sink
> was too hot to leave my hand on for any length of time.
>
> So I'd guess that you're fine, now that you've done the initial
> re-tightening.
>


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