When Transmitting on FT8 - KPA500 has issues - KD8ZYD

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When Transmitting on FT8 - KPA500 has issues - KD8ZYD

KD8ZYD - Fred
Hi,

I have a K3, P3, KPA500, KAT500 and a SignaLink for sound.  Sometimes when
I transmit on FT8 running full power on the KPA500, the KPA500 will click
on/off.  The power doesn't turn on/off, it seems like a relay inside.  The
power meter will go to about 500 watts, then down to 0, then to abut 500
watts...and down to 0 maybe once a second.  I have a short video I can send
if someone would like to see it.  When I bypass the KPA500 and use 50 watts
or so just on the K3, no issues.

Please let me know if you have any questions.

73, Fred

KD8ZYD
--
Thanks,

Fred
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Re: When Transmitting on FT8 - KPA500 has issues - KD8ZYD

wa2lbi@gmail.com
Fred,

Does this condition also happen on SSB, RTTY, CW or only while running
digital mode?

Is it possible the PTT/key line is being dropped?  When the power drops is
there an asterisk (*) on the left side of the KPA500 display?  An asterisk
will appear on the left side of the LCD display if there is a valid PA KEY/
PTT signal is being received from the transceiver. If there is no asterisk
the amp isn't receiving a valid PA KEY/PTT signal from the transceiver.  If
there is an underscore instead of an asterisk it means that the amplifier
keying is being inhibited by a low signal on pin 11 of the AUX connector.

Ken
WA2LBI





On Mon, Jul 1, 2019 at 9:06 PM Fred <[hidden email]> wrote:

> Hi,
>
> I have a K3, P3, KPA500, KAT500 and a SignaLink for sound.  Sometimes when
> I transmit on FT8 running full power on the KPA500, the KPA500 will click
> on/off.  The power doesn't turn on/off, it seems like a relay inside.  The
> power meter will go to about 500 watts, then down to 0, then to abut 500
> watts...and down to 0 maybe once a second.  I have a short video I can send
> if someone would like to see it.  When I bypass the KPA500 and use 50 watts
> or so just on the K3, no issues.
>
> Please let me know if you have any questions.
>
> 73, Fred
>
> KD8ZYD
> --
> Thanks,
>
> Fred
>
>
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Re: When Transmitting on FT8 - KPA500 has issues - KD8ZYD

Jim Brown-10
In reply to this post by KD8ZYD - Fred
How are you setting power out?  The K3 power out should be set to about
25W to get full power.  What SWR do the KPA500 indicate and KAT500
indicate?

73, Jim K9YC

On 7/1/2019 6:05 PM, Fred wrote:

> Hi,
>
> I have a K3, P3, KPA500, KAT500 and a SignaLink for sound.  Sometimes when
> I transmit on FT8 running full power on the KPA500, the KPA500 will click
> on/off.  The power doesn't turn on/off, it seems like a relay inside.  The
> power meter will go to about 500 watts, then down to 0, then to abut 500
> watts...and down to 0 maybe once a second.  I have a short video I can send
> if someone would like to see it.  When I bypass the KPA500 and use 50 watts
> or so just on the K3, no issues.
>
> Please let me know if you have any questions.
>
> 73, Fred
>
> KD8ZYD


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Re: When Transmitting on FT8 - KPA500 has issues - KD8ZYD

Don Wilhelm
In reply to this post by KD8ZYD - Fred
Fred,

Is the KAT500 trying to do a TUNE?  It sounds like it may be.
If left in AUTO mode, the KAT500 can occasionally detect a false SWR
result.  When that happens, the KAT500 will break the keying line to the
KPA500 while it tunes.

With the KAT500 in AUTO - train the tuner for all band segments and
antennas you use, then set the KAT500 to MAN for operation.

Do that and see if the problem stops.

If that is not the problem, connect the KPA500 (not the KAT500) to a 500
watt or greater dummy load and see if you can duplicate the problem.

If it fails on the dummy load, contact [hidden email].

73,
Don W3FPR

On 7/1/2019 9:05 PM, Fred wrote:

> Hi,
>
> I have a K3, P3, KPA500, KAT500 and a SignaLink for sound.  Sometimes when
> I transmit on FT8 running full power on the KPA500, the KPA500 will click
> on/off.  The power doesn't turn on/off, it seems like a relay inside.  The
> power meter will go to about 500 watts, then down to 0, then to abut 500
> watts...and down to 0 maybe once a second.  I have a short video I can send
> if someone would like to see it.  When I bypass the KPA500 and use 50 watts
> or so just on the K3, no issues.
>
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Re: When Transmitting on FT8 - KPA500 has issues - KD8ZYD

KD8ZYD - Fred
In reply to this post by wa2lbi@gmail.com
Hi Ken,

It only happens when running digital mode FT8. And it doesn’t happen all the time when running digital mode. Ken I’ll send the video I made. I just looked at it and it has an *.

Thanks,

Fred
248-613-4086

Sent from my iPhone

> On Jul 1, 2019, at 9:22 PM, Ken Winterling <[hidden email]> wrote:
>
> Fred,
>
> Does this condition also happen on SSB, RTTY, CW or only while running digital mode?
>
> Is it possible the PTT/key line is being dropped?  When the power drops is there an asterisk (*) on the left side of the KPA500 display?  An asterisk will appear on the left side of the LCD display if there is a valid PA KEY/PTT signal is being received from the transceiver. If there is no asterisk the amp isn't receiving a valid PA KEY/PTT signal from the transceiver.  If there is an underscore instead of an asterisk it means that the amplifier keying is being inhibited by a low signal on pin 11 of the AUX connector.
>
> Ken
> WA2LBI
>  
>
>
>
>
>> On Mon, Jul 1, 2019 at 9:06 PM Fred <[hidden email]> wrote:
>> Hi,
>>
>> I have a K3, P3, KPA500, KAT500 and a SignaLink for sound.  Sometimes when
>> I transmit on FT8 running full power on the KPA500, the KPA500 will click
>> on/off.  The power doesn't turn on/off, it seems like a relay inside.  The
>> power meter will go to about 500 watts, then down to 0, then to abut 500
>> watts...and down to 0 maybe once a second.  I have a short video I can send
>> if someone would like to see it.  When I bypass the KPA500 and use 50 watts
>> or so just on the K3, no issues.
>>
>> Please let me know if you have any questions.
>>
>> 73, Fred
>>
>> KD8ZYD
>> --
>> Thanks,
>>
>> Fred
>>
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Re: When Transmitting on FT8 - KPA500 has issues - KD8ZYD

Mark Goldberg
Can you watch the SWR when this happens? If the antenna is hard to tune,
the tuner may find a match, but it may actually be fairly lossy, with power
being dissipated in the tuner. As the tuner inductors heat up, they change
value, and the SWR goes up, triggering a retune. You should be able to see
the same thing with just a carrier at high power. If that is the case, you
should do something to your antenna to make it easier to tune up. This
happens to me on 160. My antenna is too short and presents a low impedance.
The tuner can tune it, but not for very long before it heats up.On SSB or
CW, the lower duty cycle doesn't heat things up as much.

73,

Mark
W7MLG


On Mon, Jul 1, 2019 at 6:29 PM Fred <[hidden email]> wrote:

> Hi Ken,
>
> It only happens when running digital mode FT8. And it doesn’t happen all
> the time when running digital mode. Ken I’ll send the video I made. I just
> looked at it and it has an *.
>
> Thanks,
>
> Fred
> 248-613-4086
>
> Sent from my iPhone
>
> > On Jul 1, 2019, at 9:22 PM, Ken Winterling <[hidden email]> wrote:
> >
> > Fred,
> >
> > Does this condition also happen on SSB, RTTY, CW or only while running
> digital mode?
> >
> > Is it possible the PTT/key line is being dropped?  When the power drops
> is there an asterisk (*) on the left side of the KPA500 display?  An
> asterisk will appear on the left side of the LCD display if there is a
> valid PA KEY/PTT signal is being received from the transceiver. If there is
> no asterisk the amp isn't receiving a valid PA KEY/PTT signal from the
> transceiver.  If there is an underscore instead of an asterisk it means
> that the amplifier keying is being inhibited by a low signal on pin 11 of
> the AUX connector.
> >
> > Ken
> > WA2LBI
> >
> >
> >
> >
> >
> >> On Mon, Jul 1, 2019 at 9:06 PM Fred <[hidden email]> wrote:
> >> Hi,
> >>
> >> I have a K3, P3, KPA500, KAT500 and a SignaLink for sound.  Sometimes
> when
> >> I transmit on FT8 running full power on the KPA500, the KPA500 will
> click
> >> on/off.  The power doesn't turn on/off, it seems like a relay inside.
> The
> >> power meter will go to about 500 watts, then down to 0, then to abut 500
> >> watts...and down to 0 maybe once a second.  I have a short video I can
> send
> >> if someone would like to see it.  When I bypass the KPA500 and use 50
> watts
> >> or so just on the K3, no issues.
> >>
> >> Please let me know if you have any questions.
> >>
> >> 73, Fred
> >>
> >> KD8ZYD
> >> --
> >> Thanks,
> >>
> >> Fred
> >>
> ______________________________________________________________
> 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
> Message delivered to [hidden email]
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Re: When Transmitting on FT8 - KPA500 has issues - KD8ZYD

Bob McGraw - K4TAX
In reply to this post by KD8ZYD - Fred
Sounds like the power from the K3 is too high.   Should be about 25 or
so watts.  Actually, 20 watts drives my KPA500 to 500 watts output on
all bands.  I trust the SWR as seen by the amplifier is 1.5:1 or less.

Do you get any FAULT LED indications on the KPA500? You can use the
KPA500 Utility to download and examine the fault table.

73

Bob, K4TAX


On 7/1/2019 8:05 PM, Fred wrote:

> Hi,
>
> I have a K3, P3, KPA500, KAT500 and a SignaLink for sound.  Sometimes when
> I transmit on FT8 running full power on the KPA500, the KPA500 will click
> on/off.  The power doesn't turn on/off, it seems like a relay inside.  The
> power meter will go to about 500 watts, then down to 0, then to abut 500
> watts...and down to 0 maybe once a second.  I have a short video I can send
> if someone would like to see it.  When I bypass the KPA500 and use 50 watts
> or so just on the K3, no issues.
>
> Please let me know if you have any questions.
>
> 73, Fred
>
> KD8ZYD

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Re: When Transmitting on FT8 - KPA500 has issues - KD8ZYD

Elecraft mailing list
Fred sent me the video, which is actually very revealing. First the change rate is very rapid, higher than I initially expected. The asterisk is on constantly, and the power off time is not long enough for power to drop to zero. But what I found very interesting is that the output power indication on the K3 is fluctuating at the same rate as the KPA500 is indicating. That leads me to believe that the K3 output is rapidly changing on and off. The next question is what might be causing this - it might be the K3, but it also could be upstream, in Fred’s Signalink or perhaps the computer / program that is feeding audio to the radio system.

With that in mind, and knowing the calibre of folks on the list who are very adept at digital setups, let's see if we can troubleshoot the system and get Fred going again the way things should be.

73!
Jack, W6FB


> On Jul 1, 2019, at 7:32 PM, Bob McGraw K4TAX <[hidden email]> wrote:
>
> Sounds like the power from the K3 is too high.   Should be about 25 or so watts.  Actually, 20 watts drives my KPA500 to 500 watts output on all bands.  I trust the SWR as seen by the amplifier is 1.5:1 or less.
>
> Do you get any FAULT LED indications on the KPA500? You can use the KPA500 Utility to download and examine the fault table.
>
> 73
>
> Bob, K4TAX
>
>
> On 7/1/2019 8:05 PM, Fred wrote:
>> Hi,
>>
>> I have a K3, P3, KPA500, KAT500 and a SignaLink for sound.  Sometimes when
>> I transmit on FT8 running full power on the KPA500, the KPA500 will click
>> on/off.  The power doesn't turn on/off, it seems like a relay inside.  The
>> power meter will go to about 500 watts, then down to 0, then to abut 500
>> watts...and down to 0 maybe once a second.  I have a short video I can send
>> if someone would like to see it.  When I bypass the KPA500 and use 50 watts
>> or so just on the K3, no issues.
>>
>> Please let me know if you have any questions.
>>
>> 73, Fred
>>
>> KD8ZYD
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
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>
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> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]

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Re: When Transmitting on FT8 - KPA500 has issues - KD8ZYD

Michael Walker
Good to send the video

It sounds like the Sound card is dropping audio frames then and can he test
with WSJTx in their TUNE mode.  Does the same thing happen.

If it was me, I would review the sound card settings for the sound card
device.  Make sure it IS the one you think it is.

Could the computer be suffering from high DPCs.. aka, is it busy doing
something else like a virus scan or indexing?

This is one of those times that it would be good to know more about the
computer hardware, like CPU speed, memory, etc.

Mike va3mw


On Mon, Jul 1, 2019 at 11:15 PM Jack Brindle via Elecraft <
[hidden email]> wrote:

> Fred sent me the video, which is actually very revealing. First the change
> rate is very rapid, higher than I initially expected. The asterisk is on
> constantly, and the power off time is not long enough for power to drop to
> zero. But what I found very interesting is that the output power indication
> on the K3 is fluctuating at the same rate as the KPA500 is indicating. That
> leads me to believe that the K3 output is rapidly changing on and off. The
> next question is what might be causing this - it might be the K3, but it
> also could be upstream, in Fred’s Signalink or perhaps the computer /
> program that is feeding audio to the radio system.
>
> With that in mind, and knowing the calibre of folks on the list who are
> very adept at digital setups, let's see if we can troubleshoot the system
> and get Fred going again the way things should be.
>
> 73!
> Jack, W6FB
>
>
> > On Jul 1, 2019, at 7:32 PM, Bob McGraw K4TAX <[hidden email]>
> wrote:
> >
> > Sounds like the power from the K3 is too high.   Should be about 25 or
> so watts.  Actually, 20 watts drives my KPA500 to 500 watts output on all
> bands.  I trust the SWR as seen by the amplifier is 1.5:1 or less.
> >
> > Do you get any FAULT LED indications on the KPA500? You can use the
> KPA500 Utility to download and examine the fault table.
> >
> > 73
> >
> > Bob, K4TAX
> >
> >
> > On 7/1/2019 8:05 PM, Fred wrote:
> >> Hi,
> >>
> >> I have a K3, P3, KPA500, KAT500 and a SignaLink for sound.  Sometimes
> when
> >> I transmit on FT8 running full power on the KPA500, the KPA500 will
> click
> >> on/off.  The power doesn't turn on/off, it seems like a relay inside.
> The
> >> power meter will go to about 500 watts, then down to 0, then to abut 500
> >> watts...and down to 0 maybe once a second.  I have a short video I can
> send
> >> if someone would like to see it.  When I bypass the KPA500 and use 50
> watts
> >> or so just on the K3, no issues.
> >>
> >> Please let me know if you have any questions.
> >>
> >> 73, Fred
> >>
> >> KD8ZYD
> >
> > ______________________________________________________________
> > Elecraft mailing list
> > Home: http://mailman.qth.net/mailman/listinfo/elecraft
> > Help: http://mailman.qth.net/mmfaq.htm
> > Post: mailto:[hidden email]
> >
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> > Please help support this email list: http://www.qsl.net/donate.html
> > Message delivered to [hidden email]
>
> ______________________________________________________________
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> Please help support this email list: http://www.qsl.net/donate.html
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When Transmitting on FT8 - KPA500 has issues - KD8ZYD

ANDY DURBIN
In reply to this post by KD8ZYD - Fred
"That leads me to believe that the K3 output is rapidly changing on and off"

I have not looked at the video but this sounds very similar to a problem I have seen.   In my case HDSDR sound output had spontaneously changed to TS-590 TX CODEC creating a feedback loop through the PC.  Break the loop and all is normal.

73,
Andy, k3wyc
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Re: When Transmitting on FT8 - KPA500 has issues - KD8ZYD

Bob McGraw - K4TAX
A clue..... at 500 watts with the KPA500 there is an issue.  At 50 watts
using just the K3 there is no reported issue.  What's the difference?  
RF field strength.  Sounds like it might be and RFI issue.

Check all PL-259's and make sure they are VERY TIGHT.   Check jumper
cables, between each piece of equipment and make sure they are in good
condition and connectors are properly attached and installed.   If in
doubt, replace them.

73

Bob, K4TAX

On 7/1/2019 10:44 PM, Andy Durbin wrote:

> "That leads me to believe that the K3 output is rapidly changing on and off"
>
> I have not looked at the video but this sounds very similar to a problem I have seen.   In my case HDSDR sound output had spontaneously changed to TS-590 TX CODEC creating a feedback loop through the PC.  Break the loop and all is normal.
>
> 73,
> Andy, k3wyc
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
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>

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Re: When Transmitting on FT8 - KPA500 has issues - KD8ZYD

Mark Goldberg
I'm going to take these two postings and suggest the possibility of RF
getting into the USB link to the PC causing it to drop samples.

Check the grounds and make sure there is a good ground connection between
the PC, Signalink and the radio equipment. Try ferrite beads (Mix 31) on
the USB line or a different USB cable.

73,

Mark
W7MLG


On Mon, Jul 1, 2019 at 9:06 PM Bob McGraw K4TAX <[hidden email]> wrote:

> A clue..... at 500 watts with the KPA500 there is an issue.  At 50 watts
> using just the K3 there is no reported issue.  What's the difference?
> RF field strength.  Sounds like it might be and RFI issue.
>
> Check all PL-259's and make sure they are VERY TIGHT.   Check jumper
> cables, between each piece of equipment and make sure they are in good
> condition and connectors are properly attached and installed.   If in
> doubt, replace them.
>
> 73
>
> Bob, K4TAX
>



On Mon, Jul 1, 2019 at 8:41 PM Michael Walker <[hidden email]> wrote:

> Good to send the video
>
> It sounds like the Sound card is dropping audio frames then and can he test
> with WSJTx in their TUNE mode.  Does the same thing happen.
>
> If it was me, I would review the sound card settings for the sound card
> device.  Make sure it IS the one you think it is.
>
> Could the computer be suffering from high DPCs.. aka, is it busy doing
> something else like a virus scan or indexing?
>
> This is one of those times that it would be good to know more about the
> computer hardware, like CPU speed, memory, etc.
>
> Mike va3mw
>
>
> On Mon, Jul 1, 2019 at 11:15 PM Jack Brindle via Elecraft <
> [hidden email]> wrote:
>
> > Fred sent me the video, which is actually very revealing. First the
> change
> > rate is very rapid, higher than I initially expected. The asterisk is on
> > constantly, and the power off time is not long enough for power to drop
> to
> > zero. But what I found very interesting is that the output power
> indication
> > on the K3 is fluctuating at the same rate as the KPA500 is indicating.
> That
> > leads me to believe that the K3 output is rapidly changing on and off.
> The
> > next question is what might be causing this - it might be the K3, but it
> > also could be upstream, in Fred’s Signalink or perhaps the computer /
> > program that is feeding audio to the radio system.
> >
> > With that in mind, and knowing the calibre of folks on the list who are
> > very adept at digital setups, let's see if we can troubleshoot the system
> > and get Fred going again the way things should be.
> >
> > 73!
> > Jack, W6FB
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Re: When Transmitting on FT8 - KPA500 has issues - KD8ZYD

KD8ZYD - Fred
In reply to this post by KD8ZYD - Fred
I’m going to try and answer all the questions that have shown up in this
thread.  I really appreciate all the ideas and things to check.  I do have
a day job (7 years to go) so I only have time to play with this at night
and try and debug.



I drive my KPA 500 with somewhere between 20 and 25 watts from the K3
depending on the band



I do not get any faults on the KPA 500 or KAT 500.



The fault log on the KPA 500 was clean



I will test with WSJTx in the Tune mode and report back.  I will check the
sound card settings to make sure they are correct



My computer is home built, i5-4590 CPU @ 3.3 GHz, 16 GB Memory, SSD Drive,
decent graphics card



Andy, K3WYC posted - I have not looked at the video but this sounds very
similar to a problem I have seen.   In my case HDSDR sound output had
spontaneously changed to TS-590 TX CODEC creating a feedback loop through
the PC.  Break the loop and all is normal.  – Question, how do you break
the loop?



All connections are good.  When I built the K-Line, I made all new Co-ax
cables with Amphenol connectors.  All Elecraft cables are less than 2 years
old.



I need to add a ground from my MFJ Anderson Power Poll connection strip.
Everything else is grounded to a ground bar, to a 10 foot copper rod
outside the house, connected to another 10 foot copper rod at my tower and
so on.



I have not tried to see if this happens at 200 watts.  I need to pay
attention to see if it happens just on certain bands, or only on my Mosley
or my wire dipole.  It never happens if I am not using the KPA 500.



Jack, W6FB if I let this go and check things as it is happening, do you
think I could damage my equipment?  That is one thing that worries me so
when it happens, I kill the transmit ASAP



I want to thank everyone in the Elecraft community for all the replies!!
Thanks a lot!!



Please let me know if anyone has any other questions.



Fred, KD8ZYD

--
Thanks,

Fred
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Re: When Transmitting on FT8 - KPA500 has issues - KD8ZYD

ANDY DURBIN
In reply to this post by ANDY DURBIN
"In my case HDSDR sound output had spontaneously changed to TS-590 TX CODEC creating a feedback loop through
the PC.  Break the loop and all is normal.  

– Question, how do you break the loop?"

In my case I simply changed HDSDR sound output back to the Virtual Audio Cable it was intended to be assigned to.   If not using VAC the normal output selection would probably be PC speakers.

The symptoms of the feedback loop were oscillation of power output and TS-590 ALC at about 1 Hz.   The oscillation frequency depends on the delay between signal detection by my SDRPlay RSP, demodulation by HDSDR, and output on PC USB audio to the TS-590.   Seen it several times.  The first time was quite alarming.  Quick fix is to kill HDSDR.

I don't remember hearing any relay click at 1 Hz but I suppose it's possible the feedback loop could cause the KPA500 attenuator relay to activate.

73,
Andy, k3wyc

73,
Andy, k3wyc


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Re: When Transmitting on FT8 - KPA500 has issues - KD8ZYD

Nr4c
In reply to this post by KD8ZYD - Fred
Does this happen without the amp?  

Sent from my iPhone
...nr4c. bill


> On Jul 2, 2019, at 8:13 PM, Fred <[hidden email]> wrote:
>
> I’m going to try and answer all the questions that have shown up in this
> thread.  I really appreciate all the ideas and things to check.  I do have
> a day job (7 years to go) so I only have time to play with this at night
> and try and debug.
>
>
>
> I drive my KPA 500 with somewhere between 20 and 25 watts from the K3
> depending on the band
>
>
>
> I do not get any faults on the KPA 500 or KAT 500.
>
>
>
> The fault log on the KPA 500 was clean
>
>
>
> I will test with WSJTx in the Tune mode and report back.  I will check the
> sound card settings to make sure they are correct
>
>
>
> My computer is home built, i5-4590 CPU @ 3.3 GHz, 16 GB Memory, SSD Drive,
> decent graphics card
>
>
>
> Andy, K3WYC posted - I have not looked at the video but this sounds very
> similar to a problem I have seen.   In my case HDSDR sound output had
> spontaneously changed to TS-590 TX CODEC creating a feedback loop through
> the PC.  Break the loop and all is normal.  – Question, how do you break
> the loop?
>
>
>
> All connections are good.  When I built the K-Line, I made all new Co-ax
> cables with Amphenol connectors.  All Elecraft cables are less than 2 years
> old.
>
>
>
> I need to add a ground from my MFJ Anderson Power Poll connection strip.
> Everything else is grounded to a ground bar, to a 10 foot copper rod
> outside the house, connected to another 10 foot copper rod at my tower and
> so on.
>
>
>
> I have not tried to see if this happens at 200 watts.  I need to pay
> attention to see if it happens just on certain bands, or only on my Mosley
> or my wire dipole.  It never happens if I am not using the KPA 500.
>
>
>
> Jack, W6FB if I let this go and check things as it is happening, do you
> think I could damage my equipment?  That is one thing that worries me so
> when it happens, I kill the transmit ASAP
>
>
>
> I want to thank everyone in the Elecraft community for all the replies!!
> Thanks a lot!!
>
>
>
> Please let me know if anyone has any other questions.
>
>
>
> Fred, KD8ZYD
>
> --
> Thanks,
>
> Fred
> ______________________________________________________________
> 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
> Message delivered to [hidden email]

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Re: When Transmitting on FT8 - KPA500 has issues - KD8ZYD

Don Wilhelm
In reply to this post by ANDY DURBIN
Andy,

That appears to be a TS-590/HDSDR problem and not a KPA500 problem.
You can likely get more support from th TS-590 and HDSDR forums than
from us on the Elecraft reflector.

73,
Don W3FPR

On 7/2/2019 10:19 PM, Andy Durbin wrote:
> "In my case HDSDR sound output had spontaneously changed to TS-590 TX CODEC creating a feedback loop through
> the PC.  Break the loop and all is normal.
>
> – Question, how do you break the loop?"
>
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Re: When Transmitting on FT8 - KPA500 has issues - KD8ZYD

David Haines
In reply to this post by KD8ZYD - Fred
I haven't been following this thread closely, but it sounds like what
has been going on with my K3X with KXPA100 and internal ATU on FT8.

Transmitting with 100w, the relays click rapidly while the power meter
on the KXPA100  jumps up and down.  Seems to be trying to find a match
that's not there.  I've been trying different settings and the problem
goes away when I increase the "power" (audio output) slider on WSJT-X. 
Increasing MIC GAIN and reducing the WSJT-X "power" slider seems to fix
it too. Does this make sense to anybody?

73, David, KC1DNY

On 7/1/2019 9:26 PM, Fred wrote:

> Hi Ken,
>
> It only happens when running digital mode FT8. And it doesn’t happen all the time when running digital mode. Ken I’ll send the video I made. I just looked at it and it has an *.
>
> Thanks,
>
> Fred
> 248-613-4086
>
> Sent from my iPhone
>
>> On Jul 1, 2019, at 9:22 PM, Ken Winterling <[hidden email]> wrote:
>>
>> Fred,
>>
>> Does this condition also happen on SSB, RTTY, CW or only while running digital mode?
>>
>> Is it possible the PTT/key line is being dropped?  When the power drops is there an asterisk (*) on the left side of the KPA500 display?  An asterisk will appear on the left side of the LCD display if there is a valid PA KEY/PTT signal is being received from the transceiver. If there is no asterisk the amp isn't receiving a valid PA KEY/PTT signal from the transceiver.  If there is an underscore instead of an asterisk it means that the amplifier keying is being inhibited by a low signal on pin 11 of the AUX connector.
>>
>> Ken
>> WA2LBI
>>  
>>
>>
>>
>>
>>> On Mon, Jul 1, 2019 at 9:06 PM Fred <[hidden email]> wrote:
>>> Hi,
>>>
>>> I have a K3, P3, KPA500, KAT500 and a SignaLink for sound.  Sometimes when
>>> I transmit on FT8 running full power on the KPA500, the KPA500 will click
>>> on/off.  The power doesn't turn on/off, it seems like a relay inside.  The
>>> power meter will go to about 500 watts, then down to 0, then to abut 500
>>> watts...and down to 0 maybe once a second.  I have a short video I can send
>>> if someone would like to see it.  When I bypass the KPA500 and use 50 watts
>>> or so just on the K3, no issues.
>>>
>>> Please let me know if you have any questions.
>>>
>>> 73, Fred
>>>
>>> KD8ZYD
>>> --
>>> Thanks,
>>>
>>> Fred
>>>
> ______________________________________________________________
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