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KS3 internal 100 watt amp (K3S/100) is intermittent

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KS3 internal 100 watt amp (K3S/100) is intermittent

Rig: K3S (100W with internal ATU), s/n 11064, P3, KPA500, KAT500, into SteppIR 3-el with 30/40 loop or wire dipoles/inverted-V's.

Problem: My K3S 100 watt internal amplifier unit (K3S/100) has become intermittent.

It first happened yesterday while I was running 100W on FT-8. [I have done this hundreds of times, sometimes for lengthy periods, over the past 18 months with no problems.]
Suddenly, my power output dropped to zero, and my received signals audio and P3 display also suddenly went quiet.

After some fiddling around, I figured out that if I reduced the K3S power to 10-12 watts, both transmit and receive came on again — leading me to conclude that it must be my 100W amp unit that had dropped out.

I rebooted the rig and the 100W internal amp unit kicked back on. So I was hoping I had just triggered a protective circuit which had reset. The rig worked fine at 100W for a subsequent hour-long multi-band CWOPs CWT CW session at 100W. Then, however, a few minutes into the next CWT session hours later, the same thing happened again. Power output suddenly dropped from 100W to 0, and received audio and a P-3 screen filled with many medium to strong CWOPs signals simultaneously went quiet.

I reduced the power on the K3S down to 10W, and both transmit and receive worked again, but only at low power.
Please pass along any helpful suggestions, and thanks!
Richard Hoffman (Rich), K1DJScituate, MA
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Vic Rosenthal

Re: KS3 internal 100 watt amp (K3S/100) is intermittent

Rich,

Try removing and reseating the amplifier module several times.
Some people suggest Deoxit, but the regular version of Deoxit is not
designed for gold plated contacts, and I don't know if these are or not.
Use caution.

I'd blame FT8, but some guys don't have a sense of humor.

73,
Victor, 4X6GP
Rehovot, Israel
Formerly K2VCO
CWops no. 5
http://www.qsl.net/k2vco/
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Joe DeVincentis

Re: KS3 internal 100 watt amp (K3S/100) is intermittent

In reply to this post by Elecraft mailing list

Could it be overheating? Or is the temperature calibration is out of whack.

Joe,
KO8V

> On Aug 1, 2019, at 10:16, Richard Hoffman, K1DJ via Elecraft <[hidden email]> wrote:
>
> Rig: K3S (100W with internal ATU), s/n 11064, P3, KPA500, KAT500, into SteppIR 3-el with 30/40 loop or wire dipoles/inverted-V's.
>
> Problem: My K3S 100 watt internal amplifier unit (K3S/100) has become intermittent.
>
> It first happened yesterday while I was running 100W on FT-8. [I have done this hundreds of times, sometimes for lengthy periods, over the past 18 months with no problems.]
> Suddenly, my power output dropped to zero, and my received signals audio and P3 display also suddenly went quiet.
>
> After some fiddling around, I figured out that if I reduced the K3S power to 10-12 watts, both transmit and receive came on again — leading me to conclude that it must be my 100W amp unit that had dropped out.
>
> I rebooted the rig and the 100W internal amp unit kicked back on. So I was hoping I had just triggered a protective circuit which had reset. The rig worked fine at 100W for a subsequent hour-long multi-band CWOPs CWT CW session at 100W. Then, however, a few minutes into the next CWT session hours later, the same thing happened again. Power output suddenly dropped from 100W to 0, and received audio and a P-3 screen filled with many medium to strong CWOPs signals simultaneously went quiet.
>
> I reduced the power on the K3S down to 10W, and both transmit and receive worked again, but only at low power.
> Please pass along any helpful suggestions, and thanks!
> Richard Hoffman (Rich), K1DJScituate, MA

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Bob McGraw - K4TAX

Re: KS3 internal 100 watt amp (K3S/100) is intermittent

Is there an ATU involved? If so , the TX signal and RX signal are then common to the path through the ATU.

I don't think the RX signal goes through the 100W PA.

Also consider the antenna port switching. That is common to both RX and TX signal paths.

Bob, K4TAX

Sent from my iPhone

> On Aug 1, 2019, at 10:18 AM, Joe DeVincentis <[hidden email]> wrote:
>
> Could it be overheating? Or is the temperature calibration is out of whack.
>
> Joe,
> KO8V
>
>> On Aug 1, 2019, at 10:16, Richard Hoffman, K1DJ via Elecraft <[hidden email]> wrote:
>>
>> Rig: K3S (100W with internal ATU), s/n 11064, P3, KPA500, KAT500, into SteppIR 3-el with 30/40 loop or wire dipoles/inverted-V's.
>>
>> Problem: My K3S 100 watt internal amplifier unit (K3S/100) has become intermittent.
>>
>> It first happened yesterday while I was running 100W on FT-8. [I have done this hundreds of times, sometimes for lengthy periods, over the past 18 months with no problems.]
>> Suddenly, my power output dropped to zero, and my received signals audio and P3 display also suddenly went quiet.
>>
>> After some fiddling around, I figured out that if I reduced the K3S power to 10-12 watts, both transmit and receive came on again — leading me to conclude that it must be my 100W amp unit that had dropped out.
>>
>> I rebooted the rig and the 100W internal amp unit kicked back on. So I was hoping I had just triggered a protective circuit which had reset. The rig worked fine at 100W for a subsequent hour-long multi-band CWOPs CWT CW session at 100W. Then, however, a few minutes into the next CWT session hours later, the same thing happened again. Power output suddenly dropped from 100W to 0, and received audio and a P-3 screen filled with many medium to strong CWOPs signals simultaneously went quiet.
>>
>> I reduced the power on the K3S down to 10W, and both transmit and receive worked again, but only at low power.
>> Please pass along any helpful suggestions, and thanks!
>> Richard Hoffman (Rich), K1DJScituate, MA
>
> ______________________________________________________________
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> Post: mailto:[hidden email]
>
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KENT TRIMBLE

Re: KS3 internal 100 watt amp (K3S/100) is intermittent

In reply to this post by Vic Rosenthal

This is :

https://www.google.com/amp/s/caig.com/deoxit-gold-g-series/amp/

73,

Kent K9ZTV

> On Aug 1, 2019, at 10:04 AM, Victor Rosenthal 4X6GP <[hidden email]> wrote:
>
> Rich,
>
> Try removing and reseating the amplifier module several times.
> Some people suggest Deoxit, but the regular version of Deoxit is not designed for gold plated contacts, and I don't know if these are or not. Use caution.
>
> I'd blame FT8, but some guys don't have a sense of humor.
>
> 73,
> Victor, 4X6GP
> Rehovot, Israel
> Formerly K2VCO
> CWops no. 5
> http://www.qsl.net/k2vco/
> ______________________________________________________________
> 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]

donovanf

Re: KS3 internal 100 watt amp (K3S/100) is intermittent

In reply to this post by Elecraft mailing list

Hi Rich,

Do the same error conditions occur when the radio is connected directly
to a dummy load?

73
Frank
W3LPL

----- Original Message -----

From: "Richard Hoffman, K1DJ via Elecraft" <[hidden email]>
To: [hidden email]
Sent: Thursday, August 1, 2019 2:16:31 PM
Subject: [Elecraft] KS3 internal 100 watt amp (K3S/100) is intermittent

Rig: K3S (100W with internal ATU), s/n 11064, P3, KPA500, KAT500, into SteppIR 3-el with 30/40 loop or wire dipoles/inverted-V's.

Problem: My K3S 100 watt internal amplifier unit (K3S/100) has become intermittent.

It first happened yesterday while I was running 100W on FT-8. [I have done this hundreds of times, sometimes for lengthy periods, over the past 18 months with no problems.]
Suddenly, my power output dropped to zero, and my received signals audio and P3 display also suddenly went quiet.

After some fiddling around, I figured out that if I reduced the K3S power to 10-12 watts, both transmit and receive came on again — leading me to conclude that it must be my 100W amp unit that had dropped out.

I rebooted the rig and the 100W internal amp unit kicked back on. So I was hoping I had just triggered a protective circuit which had reset. The rig worked fine at 100W for a subsequent hour-long multi-band CWOPs CWT CW session at 100W. Then, however, a few minutes into the next CWT session hours later, the same thing happened again. Power output suddenly dropped from 100W to 0, and received audio and a P-3 screen filled with many medium to strong CWOPs signals simultaneously went quiet.

I reduced the power on the K3S down to 10W, and both transmit and receive worked again, but only at low power.
Please pass along any helpful suggestions, and thanks!
Richard Hoffman (Rich), K1DJScituate, MA
______________________________________________________________
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
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Help: http://mailman.qth.net/mmfaq.htm
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Elecraft mailing list

Re: KS3 internal 100 watt amp (K3S/100) is intermittent

Yes, exactly the same, Frank.

Sent from my iPad

> On Aug 1, 2019, at 5:44 PM, [hidden email] wrote:
>
> Hi Rich,
>
> Do the same error conditions occur when the radio is connected directly
> to a dummy load?
>
> 73
> Frank
> W3LPL
>
> From: "Richard Hoffman, K1DJ via Elecraft" <[hidden email]>
> To: [hidden email]
> Sent: Thursday, August 1, 2019 2:16:31 PM
> Subject: [Elecraft] KS3 internal 100 watt amp (K3S/100) is intermittent
>
> Rig: K3S (100W with internal ATU), s/n 11064, P3, KPA500, KAT500, into SteppIR 3-el with 30/40 loop or wire dipoles/inverted-V's.
>
> Problem: My K3S 100 watt internal amplifier unit (K3S/100) has become intermittent.
>
> It first happened yesterday while I was running 100W on FT-8. [I have done this hundreds of times, sometimes for lengthy periods, over the past 18 months with no problems.]
> Suddenly, my power output dropped to zero, and my received signals audio and P3 display also suddenly went quiet.
>
> After some fiddling around, I figured out that if I reduced the K3S power to 10-12 watts, both transmit and receive came on again — leading me to conclude that it must be my 100W amp unit that had dropped out.
>
> I rebooted the rig and the 100W internal amp unit kicked back on. So I was hoping I had just triggered a protective circuit which had reset. The rig worked fine at 100W for a subsequent hour-long multi-band CWOPs CWT CW session at 100W. Then, however, a few minutes into the next CWT session hours later, the same thing happened again. Power output suddenly dropped from 100W to 0, and received audio and a P-3 screen filled with many medium to strong CWOPs signals simultaneously went quiet.
>
> I reduced the power on the K3S down to 10W, and both transmit and receive worked again, but only at low power.
> Please pass along any helpful suggestions, and thanks!
> Richard Hoffman (Rich), K1DJScituate, MA
> ______________________________________________________________
> 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]
>