Was Working Fine... Then HiCur

[W1SRD]

K2 new/old build. S/N is 2338, built base K2 and KNB2 10 years ago, put  away
and only finished up recently with KPA100, KAT100 and KSB2.



On air for couple weeks with good results. Suddenly starts giving intermittent
HiCur messages yesterday.


Tore out KPA100 and KSB2.

-Occurs on all bands tested (40, 30, 20, 17, 12, 10) (no dummy  load, but
checked R with Rig Experts AA-54 and tested close to 50 ohm  points with almost
no Z).

-Happens with Tune or keying at all power settings
-Message displays at key-up when hand keying/tune, will happen quickly with
keyer and then fold-back power.

-Cal Cur is 3.5A
-Measured power output with external wattmeter (SX-200) and power tracked fairly
closely to setting

-Will not happen if power is lowered to <
-Checked power supply output voltage with DMM and it matches the K2 display
voltage +.4V. PS is set to 14V.

-Current draw on 40M @ 12W is 2.3A 13.1V (.5V drop), 17M @ 12W = 3.44A 12.9V
(.7V drop)

-On 40M Q7 Base is .611V Q8 is .612V  
-Completely disassembled and visually inspected all solder with  magnifying
glass and re-heated common transformers and chokes in final.  Re-seated IOC and
MCU (lifted slightly and pushed back into socket).

-Checked T4 windings
-Have done the DC voltage tests suggested in the various threads about HiCurr
and everything looks normal.



73,
Steve
W1SRD
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[W1SRD]

Any suggestions or areas I can investigate from anyone?
73,
Steve




________________________________
From: Steve Dyer <[hidden email]>
To: [hidden email]
Sent: Tue, April 3, 2012 8:35:04 AM
Subject: [Elecraft] Was Working Fine... Then HiCur


K2 new/old build. S/N is 2338, built base K2 and KNB2 10 years ago, put  away
and only finished up recently with KPA100, KAT100 and KSB2.



On air for couple weeks with good results. Suddenly starts giving intermittent
HiCur messages yesterday.


Tore out KPA100 and KSB2.

-Occurs on all bands tested (40, 30, 20, 17, 12, 10) (no dummy  load, but
checked R with Rig Experts AA-54 and tested close to 50 ohm  points with almost
no Z).

-Happens with Tune or keying at all power settings
-Message displays at key-up when hand keying/tune, will happen quickly with
keyer and then fold-back power.

-Cal Cur is 3.5A
-Measured power output with external wattmeter (SX-200) and power tracked fairly

closely to setting

-Will not happen if power is lowered to <
-Checked power supply output voltage with DMM and it matches the K2 display
voltage +.4V. PS is set to 14V.

-Current draw on 40M @ 12W is 2.3A 13.1V (.5V drop), 17M @ 12W = 3.44A 12.9V
(.7V drop)

-On 40M Q7 Base is .611V Q8 is .612V  
-Completely disassembled and visually inspected all solder with  magnifying
glass and re-heated common transformers and chokes in final.  Re-seated IOC and
MCU (lifted slightly and pushed back into socket).

-Checked T4 windings
-Have done the DC voltage tests suggested in the various threads about HiCurr
and everything looks normal.



73,
Steve
W1SRD
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[Don Wilhelm-4]

Steve,

Well, I composed a reply to your question earlier, but it apparently was
not sent, sorry.

That behavior is usually caused by damaged wattmeter diodes in the
KPA100, but it sounds like you have physically removed the KPA100 and
that condition still exists.

It appears from your post that you have power control.
Check the voltage as displayed on the K2 display during transmit.  How
much does the voltage drop?
Recheck T4 and the soldering of the "link" wires, R58, Z1 and Z2.

Please confirm that it is happening with the bare base K2 - no KAT2, no
KPA100, no KAT100 connected.
If the  above is true, check the DC voltage at the cathode on D9 on the
RF board - it should be a little above 5 volts with 10 watts actual
output.  You should also have about that same voltage at Control Board
P4 pin 10 and the MCU (U6) pin 2.

73,
Don W3FPR

On 4/4/2012 3:03 PM, Steve Dyer wrote:

> Any suggestions or areas I can investigate from anyone?
> 73,
> Steve
>
>
>
>
> ________________________________
> From: Steve Dyer<[hidden email]>
> To: [hidden email]
> Sent: Tue, April 3, 2012 8:35:04 AM
> Subject: [Elecraft] Was Working Fine... Then HiCur
>
>
> K2 new/old build. S/N is 2338, built base K2 and KNB2 10 years ago, put  away
> and only finished up recently with KPA100, KAT100 and KSB2.
>
>
>
> On air for couple weeks with good results. Suddenly starts giving intermittent
> HiCur messages yesterday.
>
>
> Tore out KPA100 and KSB2.
>
> -Occurs on all bands tested (40, 30, 20, 17, 12, 10) (no dummy  load, but
> checked R with Rig Experts AA-54 and tested close to 50 ohm  points with almost
> no Z).
>
> -Happens with Tune or keying at all power settings
> -Message displays at key-up when hand keying/tune, will happen quickly with
> keyer and then fold-back power.
>
> -Cal Cur is 3.5A
> -Measured power output with external wattmeter (SX-200) and power tracked fairly
>
> closely to setting
>
> -Will not happen if power is lowered to<
> -Checked power supply output voltage with DMM and it matches the K2 display
> voltage +.4V. PS is set to 14V.
>
> -Current draw on 40M @ 12W is 2.3A 13.1V (.5V drop), 17M @ 12W = 3.44A 12.9V
> (.7V drop)
>
> -On 40M Q7 Base is .611V Q8 is .612V
> -Completely disassembled and visually inspected all solder with  magnifying
> glass and re-heated common transformers and chokes in final.  Re-seated IOC and
> MCU (lifted slightly and pushed back into socket).
>
> -Checked T4 windings
> -Have done the DC voltage tests suggested in the various threads about HiCurr
> and everything looks normal.
>
>
>
> 73,
> Steve
> W1SRD
>

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[W1SRD]

Thanks Ron. Yes, Don replied and suggested some things to look at (thanks Don!).

And yes, it does it when the KPA100 is removed.

73,
Steve
W1SRD




________________________________
From: Ron D'Eau Claire <[hidden email]>
To: Steve Dyer <[hidden email]>; [hidden email]
Sent: Wed, April 4, 2012 2:50:46 PM
Subject: RE: [Elecraft] [K2] Re:  Was Working Fine... Then HiCur

Don, W3FPR, will have suggestions. He must be away today, but he services
K2's and K2/100's and has done so for many years. He is an invaluable
resource on this reflector.

One question: Does it do the fault with the KPA100 removed? That will tell
you which part of the K2 to start looking in.

Ron AC7AC

-----Original Message-----
From: [hidden email]
[mailto:[hidden email]] On Behalf Of Steve Dyer
Sent: Wednesday, April 04, 2012 12:03 PM
To: [hidden email]
Subject: [Elecraft] [K2] Re: Was Working Fine... Then HiCur

Any suggestions or areas I can investigate from anyone?
73,
Steve




________________________________
From: Steve Dyer <[hidden email]>
To: [hidden email]
Sent: Tue, April 3, 2012 8:35:04 AM
Subject: [Elecraft] Was Working Fine... Then HiCur


K2 new/old build. S/N is 2338, built base K2 and KNB2 10 years ago, put
away and only finished up recently with KPA100, KAT100 and KSB2.



On air for couple weeks with good results. Suddenly starts giving
intermittent
HiCur messages yesterday.


Tore out KPA100 and KSB2.

-Occurs on all bands tested (40, 30, 20, 17, 12, 10) (no dummy  load, but
checked R with Rig Experts AA-54 and tested close to 50 ohm  points with
almost
no Z).

-Happens with Tune or keying at all power settings
-Message displays at key-up when hand keying/tune, will happen quickly with
keyer and then fold-back power.

-Cal Cur is 3.5A
-Measured power output with external wattmeter (SX-200) and power tracked
fairly

closely to setting

-Will not happen if power is lowered to <
-Checked power supply output voltage with DMM and it matches the K2 display
voltage +.4V. PS is set to 14V.

-Current draw on 40M @ 12W is 2.3A 13.1V (.5V drop), 17M @ 12W = 3.44A 12.9V

(.7V drop)

-On 40M Q7 Base is .611V Q8 is .612V  
-Completely disassembled and visually inspected all solder with  magnifying
glass and re-heated common transformers and chokes in final.  Re-seated IOC
and
MCU (lifted slightly and pushed back into socket).

-Checked T4 windings
-Have done the DC voltage tests suggested in the various threads about
HiCurr
and everything looks normal.



73,
Steve
W1SRD
______________________________________________________________
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
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
Post: mailto:[hidden email]

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