KPA100 Upgrade to revision D

[John E. Reiser]

Hello everyone,

I just downloaded and read the KPA100 upgrade instructions to revision D.  It is available now on the Elecraft website.

What is missing, for me anyway, is a detailed explanation from Elecraft exactly what these changes are designed to accomplish.  I have two pre-revision-D KPA100s that work fine as far as I can tell.

An explanation from Elecraft would go a long way towards motivating me to fix something that doesn't seem "broke."

Can anyone illucidate?

72 and 73,

John, W2GW

K2/100 #5570; K2/100 #4970; K1(6) #2105; KX1 #1258; KPA100(1);  etc.
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[wayne burdick]

Hi John,

The present changes are intended to eliminate the large RF choke that
had been positioned near the antenna jack (100 uH, RFC10). Some
builders had difficulty positioning this choke correctly, and in rare
cases this could lead to feedback between the amplifier and the
40-meter band-pass filter on the RF board.

With the choke out of the circuit, the amplifier should never have any
feedback on 40 meters.

If you don't have any issues with the amplifier there should be no need
to do the mods.

73,
Wayne
N6KR

On Nov 10, 2006, at 5:06 PM, John Reiser wrote:

> Hello everyone,
>
> I just downloaded and read the KPA100 upgrade instructions to revision
> D.  It is available now on the Elecraft website.
>
> What is missing, for me anyway, is a detailed explanation from
> Elecraft exactly what these changes are designed to accomplish.  I
> have two pre-revision-D KPA100s that work fine as far as I can tell.
>
> An explanation from Elecraft would go a long way towards motivating me
> to fix something that doesn't seem "broke."
>
> Can anyone illucidate?
>
> 72 and 73,
>
> John, W2GW
>

---

http://www.elecraft.com

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[Bernie Gardner]

Wayne,

On a related question, I have a K2 (5707) which is working fine in as a qrp
rig.  I purchased the KPA100 kit when I purchased the K2, but have not built
and installed it yet.  Is reasonable to assume that if I'm careful with
RFC10, there's no need to get the upgrade for the KPA 100 before I build it?

Bernie Gardner
W1AZ

On Friday 10 November 2006 20:52, wayne burdick wrote:

> Hi John,
>
> The present changes are intended to eliminate the large RF choke that
> had been positioned near the antenna jack (100 uH, RFC10). Some
> builders had difficulty positioning this choke correctly, and in rare
> cases this could lead to feedback between the amplifier and the
> 40-meter band-pass filter on the RF board.
>
> With the choke out of the circuit, the amplifier should never have any
> feedback on 40 meters.
>
> If you don't have any issues with the amplifier there should be no need
> to do the mods.
>
> 73,
> Wayne
> N6KR
>
> On Nov 10, 2006, at 5:06 PM, John Reiser wrote:
> > Hello everyone,
> >
> > I just downloaded and read the KPA100 upgrade instructions to revision
> > D.  It is available now on the Elecraft website.
> >
> > What is missing, for me anyway, is a detailed explanation from
> > Elecraft exactly what these changes are designed to accomplish.  I
> > have two pre-revision-D KPA100s that work fine as far as I can tell.
> >
> > An explanation from Elecraft would go a long way towards motivating me
> > to fix something that doesn't seem "broke."
> >
> > Can anyone illucidate?
> >
> > 72 and 73,
> >
> > John, W2GW
>
> ---
>
> http://www.elecraft.com
>
> _______________________________________________
> Elecraft mailing list
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> You must be a subscriber to post to the list.
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>
> Help: http://mailman.qth.net/subscribers.htm
> Elecraft web page: http://www.elecraft.com

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[wayne burdick]

Bernie Gardner wrote:

> Wayne,
>
> On a related question, I have a K2 (5707) which is working fine in as
> a qrp
> rig.  I purchased the KPA100 kit when I purchased the K2, but have not
> built
> and installed it yet.  Is reasonable to assume that if I'm careful with
> RFC10, there's no need to get the upgrade for the KPA 100 before I
> build it?
>

Yes, but since you haven't built it, and since the mods are so simple,
I'd suggest making them.

73,
Wayne
N6KR


---

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