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KPA500 Died

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Gary Ferdinand

KPA500 Died

Well, I’m hat in hand looking for some advice. Thanks in advance.

Configuration: K3, P3, KPA500, KAT500 to a wire. AUX cable used for control.

Symptom: K3/KAT500 loads fine into the wire with amp either off or in standby. SWR goes high and no power out when amp is online.

Possibly interesting facts:

1. Was toying with the NAQP today. Seemed ok at the time. Total failure as I was trying to make a 6 meter VHF contest Q.
2. Numerous faults in the fault table for excessive dissipation. Fault code is 11, yet no fault seen on the amp. News to me.
3. I’m totally clueless as to how to interpret the fault table timestamp as to date and time, other than most recent at top
4. Amp is dead on all bands, 160-6 (no power out, presents high swr to k3, relay heard in KAT500 at keying speed)
5. Tried a full power-off (plug pulled) with no difference
6. K3 gets the On/Off signal from the amp.
7. The amp was built by me from the kit and has provided good service for months
8. Firmware 1.33 on the amp.

There’s a very nice snowdrift out back that I’m considering throwing it into.

Tnx for any suggestions. Now back to the schematic. :-(

73/Gary W2CS

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Jack Brindle-2

Re: KPA500 Died

Ooh. Well, I hope it wasn’t punishment for “bending” the NAQP rules:
"No greater than 100 W. Use of external amplifiers capable of more than 100 W output is not allowed."
And yes, my KPA is not running while I play in NAQP...

OK, so please send me a copy of the fault table for evaluation. We will see what we can do, but I suspect we will need to get you in touch with CS on Monday.
I am sure I will hav emote questions for you after I go through the file.

Jack Brindle, W6FB
Elecraft Engineering

On Jan 18, 2014, at 3:59 PM, Gary Ferdinand <[hidden email]> wrote:

> Well, I’m hat in hand looking for some advice. Thanks in advance.
>
> Configuration: K3, P3, KPA500, KAT500 to a wire. AUX cable used for control.
>
> Symptom: K3/KAT500 loads fine into the wire with amp either off or in standby. SWR goes high and no power out when amp is online.
>
> Possibly interesting facts:
>
> 1. Was toying with the NAQP today. Seemed ok at the time. Total failure as I was trying to make a 6 meter VHF contest Q.
> 2. Numerous faults in the fault table for excessive dissipation. Fault code is 11, yet no fault seen on the amp. News to me.
> 3. I’m totally clueless as to how to interpret the fault table timestamp as to date and time, other than most recent at top
> 4. Amp is dead on all bands, 160-6 (no power out, presents high swr to k3, relay heard in KAT500 at keying speed)
> 5. Tried a full power-off (plug pulled) with no difference
> 6. K3 gets the On/Off signal from the amp.
> 7. The amp was built by me from the kit and has provided good service for months
> 8. Firmware 1.33 on the amp.
>
>
> There’s a very nice snowdrift out back that I’m considering throwing it into.
>
>
> Tnx for any suggestions. Now back to the schematic. :-(
>
> 73/Gary W2CS
>
>
>
>
>
> ______________________________________________________________
> 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

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Gary Ferdinand

Re: KPA500 Died

OK Jack.

I believe in having fun in a contest. For me, antenna challenged, that means running “high” power (500 W). It also means FYI that I use all assistance available to me such as skimmers, etc. No, I won’t submit as multi op, since I’m not. No, I won’t submit at all since I elect to maximize fun at the expense of contest rules. So, yes, my patience is short right now due to Elecraft equipment failure so I don’t appreciate the reminder of the contest rules. I never break them *and* submit a score. “Period." (To quote Pres. Obama)

As for the fault table, I’ll send that into CS on Monday so it’s tracked appropriately, etc. No need for you to spend Sunday time on it, but thanks. I was hoping another owner would have had a similar issue and could share some insight.

73

Gary Ferdinand W2CS

On Jan 18, 2014, at 7:17 PM, Jack Brindle <[hidden email]> wrote:

> Ooh. Well, I hope it wasn’t punishment for “bending” the NAQP rules:
> "No greater than 100 W. Use of external amplifiers capable of more than 100 W output is not allowed."
> And yes, my KPA is not running while I play in NAQP...
>
> OK, so please send me a copy of the fault table for evaluation. We will see what we can do, but I suspect we will need to get you in touch with CS on Monday.
> I am sure I will hav emote questions for you after I go through the file.
>
> Jack Brindle, W6FB
> Elecraft Engineering
>
> On Jan 18, 2014, at 3:59 PM, Gary Ferdinand <[hidden email]> wrote:
>
>> Well, I’m hat in hand looking for some advice. Thanks in advance.
>>
>> Configuration: K3, P3, KPA500, KAT500 to a wire. AUX cable used for control.
>>
>> Symptom: K3/KAT500 loads fine into the wire with amp either off or in standby. SWR goes high and no power out when amp is online.
>>
>> Possibly interesting facts:
>>
>> 1. Was toying with the NAQP today. Seemed ok at the time. Total failure as I was trying to make a 6 meter VHF contest Q.
>> 2. Numerous faults in the fault table for excessive dissipation. Fault code is 11, yet no fault seen on the amp. News to me.
>> 3. I’m totally clueless as to how to interpret the fault table timestamp as to date and time, other than most recent at top
>> 4. Amp is dead on all bands, 160-6 (no power out, presents high swr to k3, relay heard in KAT500 at keying speed)
>> 5. Tried a full power-off (plug pulled) with no difference
>> 6. K3 gets the On/Off signal from the amp.
>> 7. The amp was built by me from the kit and has provided good service for months
>> 8. Firmware 1.33 on the amp.
>>
>>
>> There’s a very nice snowdrift out back that I’m considering throwing it into.
>>
>>
>> Tnx for any suggestions. Now back to the schematic. :-(
>>
>> 73/Gary W2CS
>>
>>
>>
>>
>>
>> ______________________________________________________________
>> 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
>

Bill-3

Re: KPA500 Died

In reply to this post by Gary Ferdinand

Due to recent experience, I have to wonder about the KAT500???

Do you have a resonant antenna or a high power dummy load you can go to
directly - removing the KAT500 from the antenna circuit? If it works
without the tuner in line - then you have likely eliminated the KPA500
as the problem.

I did a similar test using a dummy load (Mil-Spec 2 kW) with the KAT500
in line and carried on a "QSO" while watching all the meters. After
about 45 seconds the tuner went nuts and started a retune - with no
change in frequency etc. having been made. I did this to eliminate any
futher waste of time checking and repairing non-existent antenna problems.

For the naysayers: The dummy load does not heat up at that low power.

Going directly to a dummy load eliminates everything in the antenna line(s).

Bill W2BLC K-Line
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Jack Brindle-2

Re: KPA500 Died

In reply to this post by Gary Ferdinand

Gary;

I’m sorry my attempt at humor struck you the wrong way. You would be surprised at how many avid contesters forget that NAQP is one of the few major HF contests where high power is not allowed. From out this way, high power would help a lot, especially from the postage stamp sized lots most of us have…

As for the log, if you change your mind and would like to get a head start on the diagnostic process, go ahead and forward the fault table. Having the analysis ahead of time should speed things up for the crew.

73, and try to enjoy the rest of your weekend. We will get your amp going as soon as we can.

Jack Brindle, W6FB

On Jan 18, 2014, at 4:26 PM, Gary Ferdinand <[hidden email]> wrote:

> OK Jack.
>
> I believe in having fun in a contest. For me, antenna challenged, that means running “high” power (500 W). It also means FYI that I use all assistance available to me such as skimmers, etc. No, I won’t submit as multi op, since I’m not. No, I won’t submit at all since I elect to maximize fun at the expense of contest rules. So, yes, my patience is short right now due to Elecraft equipment failure so I don’t appreciate the reminder of the contest rules. I never break them *and* submit a score. “Period." (To quote Pres. Obama)
>
> As for the fault table, I’ll send that into CS on Monday so it’s tracked appropriately, etc. No need for you to spend Sunday time on it, but thanks. I was hoping another owner would have had a similar issue and could share some insight.
>
> 73
>
> Gary Ferdinand W2CS
>
>
>
>
> On Jan 18, 2014, at 7:17 PM, Jack Brindle <[hidden email]> wrote:
>
>> Ooh. Well, I hope it wasn’t punishment for “bending” the NAQP rules:
>> "No greater than 100 W. Use of external amplifiers capable of more than 100 W output is not allowed."
>> And yes, my KPA is not running while I play in NAQP...
>>
>> OK, so please send me a copy of the fault table for evaluation. We will see what we can do, but I suspect we will need to get you in touch with CS on Monday.
>> I am sure I will hav emote questions for you after I go through the file.
>>
>> Jack Brindle, W6FB
>> Elecraft Engineering
>>
>> On Jan 18, 2014, at 3:59 PM, Gary Ferdinand <[hidden email]> wrote:
>>
>>> Well, I’m hat in hand looking for some advice. Thanks in advance.
>>>
>>> Configuration: K3, P3, KPA500, KAT500 to a wire. AUX cable used for control.
>>>
>>> Symptom: K3/KAT500 loads fine into the wire with amp either off or in standby. SWR goes high and no power out when amp is online.
>>>
>>> Possibly interesting facts:
>>>
>>> 1. Was toying with the NAQP today. Seemed ok at the time. Total failure as I was trying to make a 6 meter VHF contest Q.
>>> 2. Numerous faults in the fault table for excessive dissipation. Fault code is 11, yet no fault seen on the amp. News to me.
>>> 3. I’m totally clueless as to how to interpret the fault table timestamp as to date and time, other than most recent at top
>>> 4. Amp is dead on all bands, 160-6 (no power out, presents high swr to k3, relay heard in KAT500 at keying speed)
>>> 5. Tried a full power-off (plug pulled) with no difference
>>> 6. K3 gets the On/Off signal from the amp.
>>> 7. The amp was built by me from the kit and has provided good service for months
>>> 8. Firmware 1.33 on the amp.
>>>
>>>
>>> There’s a very nice snowdrift out back that I’m considering throwing it into.
>>>
>>>
>>> Tnx for any suggestions. Now back to the schematic. :-(
>>>
>>> 73/Gary W2CS
>>>
>>>
>>>
>>>
>>>
>>> ______________________________________________________________
>>> 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
>>
>

mcduffie

Re: KPA500 Died

In reply to this post by Bill-3

On Sat, 18 Jan 2014 19:55:58 -0500, Bill W2BLC wrote:

> I did a similar test using a dummy load (Mil-Spec 2 kW) with the KAT500
> in line and carried on a "QSO" while watching all the meters. After
> about 45 seconds the tuner went nuts and started a retune - with no
> change in frequency etc. having been made. I did this to eliminate any
> futher waste of time checking and repairing non-existent antenna problems.

So far, I cannot duplicate this at all. I know some people are experiencing it,
but I use it regularly on 160M in a part of the band far removed from resonance
of my full wave loop, and it has never retuned.

My KAT scared me one day, much like I would assume the OP was in this case. The
KPA was in operate but the tuner was interrupting the PTT line, not even a blip
occurred-no attempt to key the amp. I cycled the KAP through MAN/AUTO/BYP, and
all was good again. No clue what was going on there.

One thing that confuses me is when I first go to the 160M SSB freq at the top of
the band (antenna resonant bottom of the band). When I key up and say something
but forget to put out a quick carrier first, the KAT goes nuts. I would think
that the fast counter (it detects a dit) would at least determine that the RF is
in that band and make the switch. It won't until I put out a short carrier.

I've strayed from the topic so will sit back and hope the OP will post the
results of diagnostics and eventual cure for the problem.

Gary
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