Elecraft › [K3]

KPA3 misbehaving

Classic

List

Threaded

8 messages Options

Steve Reed

KPA3 misbehaving

Today my trusty K3 developed a strange and sudden problem -- I can't turn
the power output past 12 watts -- the KPA3 isn't clicking in! It was
working perfectly yesterday, but today not so well. Went through all the
menus, even tried resetting the radio from scratch and re-enabling the KPA3
in the config menu. The fan test works fine, and the PA test works fine
too (I can hear the relay click). But going past 12 watts with the power
control no longer works.

Anyone seen this before and know what the cause may be?

Steve, AI7AZ
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

w0mu

Re: KPA3 misbehaving

Didn't someone else have this issue recently? What is your serial
number. I believe there were issues with the pins on this board.....I
could be mistaken. DeOXit might be a cure.

Mike W0MU

W0MU-1 CC Cluster w0mu.net

On 5/4/2012 9:38 PM, Steve Reed wrote:

> Today my trusty K3 developed a strange and sudden problem -- I can't turn
> the power output past 12 watts -- the KPA3 isn't clicking in! It was
> working perfectly yesterday, but today not so well. Went through all the
> menus, even tried resetting the radio from scratch and re-enabling the KPA3
> in the config menu. The fan test works fine, and the PA test works fine
> too (I can hear the relay click). But going past 12 watts with the power
> control no longer works.
>
> Anyone seen this before and know what the cause may be?
>
> Steve, AI7AZ
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html

Steve Reed

Re: KPA3 misbehaving

In reply to this post by Steve Reed

Thanks for the speedy replies.

I should also add that the only thing I did was remove my K3 from the shack
and take it with me for use at a remote location for the 7-land QSO party
this weekend. I gently put it on the car seat and drove to the remote site
here in Arizona. When I plugged the K3 in, the power output wouldn't go
above 12 watts. It was moved around, but not roughly in any way. I took
off the top cover and checked the voltage at the PA -- the 12v was
present. Also, when I turned on the rig I received some strange"High
Current" and 12v alerts and then those went away. RX is good and the rig
otherwise operates fine, but anything about 12w is a no-go.

Steve, AI7AZ
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

Arthur Burke

Re: KPA3 misbehaving

In reply to this post by Steve Reed

This sounds like the dreaded "12v error" although you don't mention seeing
that specific message on the display.

This happened to several I've heard about, including mine (S/N 1153) and,
in my case, was the "corroded pin" problem. Elecraft sent me a kit (free of
charge) but it not only involved partial disassembly of the rig (the easy
part) it involved some soldering and, since we're talking pins here, we're
talking close quarters - at least close for someone like me.

I opted for sending the rig back to Elecraft. In the long run, I was glad I
did as a couple of other problems were discovered and rectified.
Additionally, a couple of upgrades/updates that had not been done were also
performed. It wasn't that bad overall. Despite all the hullabaloo over the
KX3, my K3 was only out of pocket for a couple of weeks.

Art - N4PJ

On Fri, May 4, 2012 at 11:38 PM, Steve Reed <[hidden email]> wrote:

Steve Reed

Re: KPA3 misbehaving

All,

Here's the latest on my K3, now that I'm back from 7QP and can put it up on
the bench and focus on this.

When the PA setting is set to "normal", I can in fact hear the relay click
when I turn the power control past 12 watts. However the display keeps
indicating "Hi Curr" and kicks it all back to 12 watts or lower. As you
turn the power knob up, you can see the power setting increase, but "Hi
Curr" keeps flashing in the display. This is all *without* the K3
transmitting. Go into transmit mode and all you get is definitely 12 watts.

The serial number is 5662.

I plan on calling Elecraft about this tomorrow. In the meantime, anyone
have some ideas?

Steve, AI7AZ
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

Steve Reed

Re: KPA3 misbehaving

OK, another update.

I tried the PA alignment procedure with the K3 utility. The 5 watt
alignment goes fine. The 50 watt alignment fails with "Hi Curr".

Removed the KPA3, checked for anything obviously loose (all looks good) and
reinstalled. Same error....

Guess this will be a call to Elecraft tomorrow, unless someone in this
forum can help.

Steve, AI7AZ

On Sun, May 6, 2012 at 10:04 AM, Steve Reed <[hidden email]> wrote:

> All,
>
> Here's the latest on my K3, now that I'm back from 7QP and can put it up
> on the bench and focus on this.
>
> When the PA setting is set to "normal", I can in fact hear the relay click
> when I turn the power control past 12 watts. However the display keeps
> indicating "Hi Curr" and kicks it all back to 12 watts or lower. As you
> turn the power knob up, you can see the power setting increase, but "Hi
> Curr" keeps flashing in the display. This is all *without* the K3
> transmitting. Go into transmit mode and all you get is definitely 12 watts.
>
> The serial number is 5662.
>
> I plan on calling Elecraft about this tomorrow. In the meantime, anyone
> have some ideas?
>
> Steve, AI7AZ
>
>
>
>

Russ Tobolic

Re: KPA3 misbehaving

Steve;

I believe you have the same problem I had a few years ago on my K3 s/n 732. It turns out that the current sensor IC, U6 on the KPAIO3 board was toast. When you go above 12W this sensor measures the current to the KPA3. There is also the same sensor (U1) on the RF board which is protected against reverse voltage on the 12V in. The sensor on the KPAIO3 board is not protected against reverse voltage as this is connected directly to the input connector. Please don't ask me how I found this out. Could you have possibly reversed the 12V to the rig momentarily? I replaced U6 and that fixed it.

Russ, N3CO

________________________________
From: Steve Reed <[hidden email]>
To: Elecraft Discussion List <[hidden email]>
Sent: Sunday, May 6, 2012 3:55 PM
Subject: Re: [Elecraft] KPA3 misbehaving

OK, another update.

I tried the PA alignment procedure with the K3 utility. The 5 watt
alignment goes fine. The 50 watt alignment fails with "Hi Curr".

Removed the KPA3, checked for anything obviously loose (all looks good) and
reinstalled. Same error....

Guess this will be a call to Elecraft tomorrow, unless someone in this
forum can help.

Steve, AI7AZ

On Sun, May 6, 2012 at 10:04 AM, Steve Reed <[hidden email]> wrote:

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

Steve Reed

Re: KPA3 misbehaving

Interesting! As far as I know the power hasn't been reversed. Possibly,
however, that current sensor has gone south for other reasons.
Fortunately, my K3 is still under warranty, I'll be talking with Elecraft
support this morning.

Steve, AI7AZ

On Mon, May 7, 2012 at 7:38 AM, Russell Tobolic <[hidden email]> wrote:

> Steve;
>
> I believe you have the same problem I had a few years ago on my K3 s/n
> 732. It turns out that the current sensor IC, U6 on the KPAIO3 board was
> toast. When you go above 12W this sensor measures the current to the KPA3.
> There is also the same sensor (U1) on the RF board which is protected
> against reverse voltage on the 12V in. The sensor on the KPAIO3 board is
> not protected against reverse voltage as this is connected directly to the
> input connector. Please don't ask me how I found this out. Could you
> have possibly reversed the 12V to the rig momentarily? I replaced U6 and
> that fixed it.
>
> Russ, N3CO
>
> ------------------------------
> *From:* Steve Reed <[hidden email]>
> *To:* Elecraft Discussion List <[hidden email]>
> *Sent:* Sunday, May 6, 2012 3:55 PM
> *Subject:* Re: [Elecraft] KPA3 misbehaving
>
> OK, another update.
>
> I tried the PA alignment procedure with the K3 utility. The 5 watt
> alignment goes fine. The 50 watt alignment fails with "Hi Curr".
>
> Removed the KPA3, checked for anything obviously loose (all looks good) and
> reinstalled. Same error....
>
> Guess this will be a call to Elecraft tomorrow, unless someone in this
> forum can help.
>
> Steve, AI7AZ
>
>
> On Sun, May 6, 2012 at 10:04 AM, Steve Reed <[hidden email]> wrote:
>
> > All,
> >
> > Here's the latest on my K3, now that I'm back from 7QP and can put it up
> > on the bench and focus on this.
> >
> > When the PA setting is set to "normal", I can in fact hear the relay
> click
> > when I turn the power control past 12 watts. However the display keeps
> > indicating "Hi Curr" and kicks it all back to 12 watts or lower. As you
> > turn the power knob up, you can see the power setting increase, but "Hi
> > Curr" keeps flashing in the display. This is all *without* the K3
> > transmitting. Go into transmit mode and all you get is definitely 12
> watts.
> >
> > The serial number is 5662.
> >
> > I plan on calling Elecraft about this tomorrow. In the meantime, anyone
> > have some ideas?
> >
> > Steve, AI7AZ
> >
> >
> >
> >
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>
>
>