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K3/AL-811 questions

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John Shadle

K3/AL-811 questions

Hi all,
This could be tangentially related to a K3 issue, or maybe K3 experts can
give some insight here. FYI, when I am not using the amp, I can get 100W
from my K3 with no problem. Please keep reading...

I have been using my AL-811 (not new, but new to me) successfully at 500W
for the past few weeks. Recently (actually, the second time this has
happened), my fuses both blew and I replaced them. Since I replaced them,
behavior has not been typical. I can't get anything over 200W (most is in
the 175W range). I use a tuner after the amp, and I know that the antenna
is matched quite well to the amp, but my SWR meter on my rig (K3) is
showing a high value.

When I tune up at 20-25W I can get about 100W out from the amp. When I move
to 50-65W I get < 200W. And there is clicking. I can't tell if it's a relay
or if it's something else.

So, the main issues are
1. High SWR from the rig to the amp (when the antenna is < 2:1 SWR to the
amp)
2. Low power from the amp to the antenna

Happy to provide other information if folks have ideas on where to look.

Thanks.
-john W4PAH
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Jim Bennett

Re: K3/AL-811 questions

John -

I've got an AL-811 but this (luckily) has not happened to me. I suggest a call to Ameritron / MFJ, as it sounds like a component in the input circuitry in the amp has gone flakey: able to withstand low amounts of RF but fails under higher power. I had an issue with my AL-811 not being able to load up on 80 meter CW - they were extremely helpful on the phone.

Jim / W6JHB

On Aug 9, 2013, at 8:37 AM, John Shadle wrote:

> Hi all,
> This could be tangentially related to a K3 issue, or maybe K3 experts can
> give some insight here. FYI, when I am not using the amp, I can get 100W
> from my K3 with no problem. Please keep reading...
>
> I have been using my AL-811 (not new, but new to me) successfully at 500W
> for the past few weeks. Recently (actually, the second time this has
> happened), my fuses both blew and I replaced them. Since I replaced them,
> behavior has not been typical. I can't get anything over 200W (most is in
> the 175W range). I use a tuner after the amp, and I know that the antenna
> is matched quite well to the amp, but my SWR meter on my rig (K3) is
> showing a high value.
>
> When I tune up at 20-25W I can get about 100W out from the amp. When I move
> to 50-65W I get < 200W. And there is clicking. I can't tell if it's a relay
> or if it's something else.
>
> So, the main issues are
> 1. High SWR from the rig to the amp (when the antenna is < 2:1 SWR to the
> amp)
> 2. Low power from the amp to the antenna
>
> Happy to provide other information if folks have ideas on where to look.
>
> Thanks.
> -john W4PAH
> ______________________________________________________________
> 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

John Shadle

Re: K3/AL-811 questions

I should also note that sometimes the amp simply being powered on (not in
OPER position, but just ON) has flipped my GFCI. This has happened a few
times.

So odd. And annoying, since my computer is also plugged in there--which
requires a restart! ;-)

-john W4PAH

On Fri, Aug 9, 2013 at 11:46 AM, Jim Bennett <[hidden email]> wrote:

> John -
>
> I've got an AL-811 but this (luckily) has not happened to me. I suggest a
> call to Ameritron / MFJ, as it sounds like a component in the input
> circuitry in the amp has gone flakey: able to withstand low amounts of RF
> but fails under higher power. I had an issue with my AL-811 not being able
> to load up on 80 meter CW - they were extremely helpful on the phone.
>
> Jim / W6JHB
>
>
> On Aug 9, 2013, at 8:37 AM, John Shadle wrote:
>
> > Hi all,
> > This could be tangentially related to a K3 issue, or maybe K3 experts can
> > give some insight here. FYI, when I am not using the amp, I can get 100W
> > from my K3 with no problem. Please keep reading...
> >
> > I have been using my AL-811 (not new, but new to me) successfully at 500W
> > for the past few weeks. Recently (actually, the second time this has
> > happened), my fuses both blew and I replaced them. Since I replaced them,
> > behavior has not been typical. I can't get anything over 200W (most is in
> > the 175W range). I use a tuner after the amp, and I know that the antenna
> > is matched quite well to the amp, but my SWR meter on my rig (K3) is
> > showing a high value.
> >
> > When I tune up at 20-25W I can get about 100W out from the amp. When I
> move
> > to 50-65W I get < 200W. And there is clicking. I can't tell if it's a
> relay
> > or if it's something else.
> >
> > So, the main issues are
> > 1. High SWR from the rig to the amp (when the antenna is < 2:1 SWR to the
> > amp)
> > 2. Low power from the amp to the antenna
> >
> > Happy to provide other information if folks have ideas on where to look.
> >
> > Thanks.
> > -john W4PAH
> > ______________________________________________________________
> > 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
>
>

Iain MacDonnell - N6ML-2

Re: K3/AL-811 questions

Definitely sounds like something is damaged in the amp. It's hard to
say what without more diagnosis than can be covered here.

That "clicking" that you hear my be arcing. You want to STOP when you
hear that, as it will cause further damage inside the amp.

Sounds like you need to find someone with experience who can help you
troubleshoot the amp... or try Ameritron support, as Jim suggests.

73,

~iain / N6ML

On Fri, Aug 9, 2013 at 8:48 AM, John Shadle <[hidden email]> wrote:

> I should also note that sometimes the amp simply being powered on (not in
> OPER position, but just ON) has flipped my GFCI. This has happened a few
> times.
>
> So odd. And annoying, since my computer is also plugged in there--which
> requires a restart! ;-)
>
> -john W4PAH
>
>
> On Fri, Aug 9, 2013 at 11:46 AM, Jim Bennett <[hidden email]> wrote:
>
>> John -
>>
>> I've got an AL-811 but this (luckily) has not happened to me. I suggest a
>> call to Ameritron / MFJ, as it sounds like a component in the input
>> circuitry in the amp has gone flakey: able to withstand low amounts of RF
>> but fails under higher power. I had an issue with my AL-811 not being able
>> to load up on 80 meter CW - they were extremely helpful on the phone.
>>
>> Jim / W6JHB
>>
>>
>> On Aug 9, 2013, at 8:37 AM, John Shadle wrote:
>>
>> > Hi all,
>> > This could be tangentially related to a K3 issue, or maybe K3 experts can
>> > give some insight here. FYI, when I am not using the amp, I can get 100W
>> > from my K3 with no problem. Please keep reading...
>> >
>> > I have been using my AL-811 (not new, but new to me) successfully at 500W
>> > for the past few weeks. Recently (actually, the second time this has
>> > happened), my fuses both blew and I replaced them. Since I replaced them,
>> > behavior has not been typical. I can't get anything over 200W (most is in
>> > the 175W range). I use a tuner after the amp, and I know that the antenna
>> > is matched quite well to the amp, but my SWR meter on my rig (K3) is
>> > showing a high value.
>> >
>> > When I tune up at 20-25W I can get about 100W out from the amp. When I
>> move
>> > to 50-65W I get < 200W. And there is clicking. I can't tell if it's a
>> relay
>> > or if it's something else.
>> >
>> > So, the main issues are
>> > 1. High SWR from the rig to the amp (when the antenna is < 2:1 SWR to the
>> > amp)
>> > 2. Low power from the amp to the antenna
>> >
>> > Happy to provide other information if folks have ideas on where to look.
>> >
>> > Thanks.
>> > -john W4PAH
>> > ______________________________________________________________
>> > 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

John Shadle

Re: K3/AL-811 questions

I called Ameritron/MFJ and they suggested that the tubes were bad and that
D16 may possibly be bad as well. Apparently that has to do with metering.

Another fellow (off-list) suggested that the GFCI blowing has to do with a
leak to the ground. So, that could be a bad tube, right? Or something
else...

Guess I should start with tubes. Best place to get the 811A tubes still RF
Parts?

Thanks.
-john W4PAH

On Fri, Aug 9, 2013 at 12:04 PM, iain macdonnell - N6ML <[hidden email]>wrote:

> Definitely sounds like something is damaged in the amp. It's hard to
> say what without more diagnosis than can be covered here.
>
> That "clicking" that you hear my be arcing. You want to STOP when you
> hear that, as it will cause further damage inside the amp.
>
> Sounds like you need to find someone with experience who can help you
> troubleshoot the amp... or try Ameritron support, as Jim suggests.
>
> 73,
>
> ~iain / N6ML
>
>
>
> On Fri, Aug 9, 2013 at 8:48 AM, John Shadle <[hidden email]>
> wrote:
> > I should also note that sometimes the amp simply being powered on (not in
> > OPER position, but just ON) has flipped my GFCI. This has happened a few
> > times.
> >
> > So odd. And annoying, since my computer is also plugged in there--which
> > requires a restart! ;-)
> >
> > -john W4PAH
> >
> >
> > On Fri, Aug 9, 2013 at 11:46 AM, Jim Bennett <[hidden email]> wrote:
> >
> >> John -
> >>
> >> I've got an AL-811 but this (luckily) has not happened to me. I suggest
> a
> >> call to Ameritron / MFJ, as it sounds like a component in the input
> >> circuitry in the amp has gone flakey: able to withstand low amounts of
> RF
> >> but fails under higher power. I had an issue with my AL-811 not being
> able
> >> to load up on 80 meter CW - they were extremely helpful on the phone.
> >>
> >> Jim / W6JHB
> >>
> >>
> >> On Aug 9, 2013, at 8:37 AM, John Shadle wrote:
> >>
> >> > Hi all,
> >> > This could be tangentially related to a K3 issue, or maybe K3 experts
> can
> >> > give some insight here. FYI, when I am not using the amp, I can get
> 100W
> >> > from my K3 with no problem. Please keep reading...
> >> >
> >> > I have been using my AL-811 (not new, but new to me) successfully at
> 500W
> >> > for the past few weeks. Recently (actually, the second time this has
> >> > happened), my fuses both blew and I replaced them. Since I replaced
> them,
> >> > behavior has not been typical. I can't get anything over 200W (most
> is in
> >> > the 175W range). I use a tuner after the amp, and I know that the
> antenna
> >> > is matched quite well to the amp, but my SWR meter on my rig (K3) is
> >> > showing a high value.
> >> >
> >> > When I tune up at 20-25W I can get about 100W out from the amp. When I
> >> move
> >> > to 50-65W I get < 200W. And there is clicking. I can't tell if it's a
> >> relay
> >> > or if it's something else.
> >> >
> >> > So, the main issues are
> >> > 1. High SWR from the rig to the amp (when the antenna is < 2:1 SWR to
> the
> >> > amp)
> >> > 2. Low power from the amp to the antenna
> >> >
> >> > Happy to provide other information if folks have ideas on where to
> look.
> >> >
> >> > Thanks.
> >> > -john W4PAH
> >> > ______________________________________________________________
> >> > 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
>

dmb@lightstream.net

Re: K3/AL-811 questions

In reply to this post by John Shadle

Hello John,

That 'clicking' could very well be arcing -- as another reader has
suggested. I have an AL-811H that has since been replaced by a KPA500 that
also made a few clicking sounds that I recognized as arcing and though I
shut it off immediately, the damage had been done. The tubes were fine,
but several of the diodes in the HV power supply, most of the bleeder
resistors as well as ALL of the filter capacitors were damaged. I suspect
it was a chain-reaction caused by a single bleeder failure which allowed
the voltage across other caps to become excessive, etc...

Fortunately, they are all easy to check and replace (capacitors held to a
pc board via screw terminals), and the cost of the components from
Ameritron/MFJ was very reasonable. After replacing them, the amp worked
just fine again.

Of course BE VERY CAREFUL when working on your amplifier, and assure that
all capacitors have been fully discharged before doing ANY work on it.

Best of luck w/ your troubleshooting.
73, Dale
WA8SRA

> Hi all,
> This could be tangentially related to a K3 issue, or maybe K3 experts can
> give some insight here. FYI, when I am not using the amp, I can get 100W
> from my K3 with no problem. Please keep reading...
>
> I have been using my AL-811 (not new, but new to me) successfully at 500W
> for the past few weeks. Recently (actually, the second time this has
> happened), my fuses both blew and I replaced them. Since I replaced them,
> behavior has not been typical. I can't get anything over 200W (most is in
> the 175W range). I use a tuner after the amp, and I know that the antenna
> is matched quite well to the amp, but my SWR meter on my rig (K3) is
> showing a high value.
>
> When I tune up at 20-25W I can get about 100W out from the amp. When I
> move
> to 50-65W I get < 200W. And there is clicking. I can't tell if it's a
> relay
> or if it's something else.
>
> So, the main issues are
> 1. High SWR from the rig to the amp (when the antenna is < 2:1 SWR to the
> amp)
> 2. Low power from the amp to the antenna
>
> Happy to provide other information if folks have ideas on where to look.
>
> Thanks.
> -john W4PAH
> ______________________________________________________________
> 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
>

Scott Manthe-2

Re: K3/AL-811 questions

In reply to this post by John Shadle

John,
It is very unlikely that the only think wrong with your amp is the
tubes. My experience with AL-811s is that if you've arced a tube, and it
sounds like you have, you'll probably have at least the D16 failure and
possibly some of the resistors at the base of the tubes, and maybe even
a cap. I don't remember exactly what failed the last time I arced a tube
in an AL-811H, but while it was more than one component, the fix wasn't
terribly bad. So that's the good news, but given the output you're
getting, it sounds like maybe you've blown two of the three tubes.

Do you know some hams there that maybe have some experience in these
kinds of issues? Madison's a decent-sized city, os there are probably a
few hams that might be able to help you out.

73 and good luck,
Scot, N9AA (A former resident of Madison...)

On 8/9/13 12:07 PM, John Shadle wrote:

> I called Ameritron/MFJ and they suggested that the tubes were bad and that
> D16 may possibly be bad as well. Apparently that has to do with metering.
>
> Another fellow (off-list) suggested that the GFCI blowing has to do with a
> leak to the ground. So, that could be a bad tube, right? Or something
> else...
>
> Guess I should start with tubes. Best place to get the 811A tubes still RF
> Parts?
>
> Thanks.
> -john W4PAH
>
>
>