Progressive Problem......

[Paul-288]

Board Members,

K2 Serial Number 3479 needs help.   Over the past couple of months an odd
little quirk developed.  When turned on the rig would do one of two
things...... after about 10-20 seconds the rig would jump from filter
setting SF1 to SF4.  This would happen by itself after being turned on and
started to warm up.  Occasionally - it did not happen in the first 10-20
seconds BUT it would happen when I would touch the volume control or power
control or rf gain control or any of the push button on the front panel.  So
either way it would (by itself or with me adjusting one of the control) it
would move from SF1 setting to the SF4 setting.  It had done this for about
a two months.

I let it go because I figured it was just a odd thing that developed with
the rig.

NOW the rig is doing this and I have lost control of the power output.  On
10 meters with the power output the display reads 1 thru 100 watts out but
in reality with a meter in line the output is only 5 watts or 100 watts
depending if I am in the low power (10 watts) or in the high power (100
watt) section of the power adjustment control.  There is nothing in between.
It gives 5 watts or 100 watts - depending only on if the dial is in the high
or low setting section.  No control even though the K2 display is showing
various settings different than 5 watts or 100 watts.

Further ... On 20 40 and 80 meters during my initial test the output was
only 20 watts.  Today  I checked it and 20 is showing 100 watts out with no
control and on 40 it is showing 125 watts out on an inline meter with the K2
display showing 25 watts out.  So the actual forward power is way off from
the display and there is no control forward power on the K2.

And the receive of the K2 is affected by the power adjustment knob.  In the
high power section of the power knob the receive and noise floor drops a
couple of s units from the low power section of the power knob adjustment.
It seems to be much more sensitive in the low power setting than the high
power setting.

Prior to this rig number 3479 was a perfectly functioning radio.


To me - this is sounding like a software problem but I honestly do not know
were to begin.  Any ideas or anyone who may have had similar problems
offering suggestions on some direction would sure be appreciated.


Thanks

Paul K8QT
Serial Number 3479

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[Ron D'Eau Claire-2]

It does sound like a software/firmware problem except that the firmware
isn't changing on its own, so something else associated with it is.

First I'd pull the control board and  inspect it very carefully with a
powerful magnifier - especially the MCU socket and associated connections -
for missed solder joints that may now be becoming intermittent as oxidation
accumulates.

Ron AC7AC

-----Original Message-----
Board Members,

K2 Serial Number 3479 needs help.   Over the past couple of months an odd
little quirk developed.  When turned on the rig would do one of two
things...... after about 10-20 seconds the rig would jump from filter
setting SF1 to SF4.  This would happen by itself after being turned on and
started to warm up.  Occasionally - it did not happen in the first 10-20
seconds BUT it would happen when I would touch the volume control or power
control or rf gain control or any of the push button on the front panel.  So

either way it would (by itself or with me adjusting one of the control) it
would move from SF1 setting to the SF4 setting.  It had done this for about
a two months.

I let it go because I figured it was just a odd thing that developed with
the rig.

NOW the rig is doing this and I have lost control of the power output.  On
10 meters with the power output the display reads 1 thru 100 watts out but
in reality with a meter in line the output is only 5 watts or 100 watts
depending if I am in the low power (10 watts) or in the high power (100
watt) section of the power adjustment control.  There is nothing in between.

It gives 5 watts or 100 watts - depending only on if the dial is in the high

or low setting section.  No control even though the K2 display is showing
various settings different than 5 watts or 100 watts.

Further ... On 20 40 and 80 meters during my initial test the output was
only 20 watts.  Today  I checked it and 20 is showing 100 watts out with no
control and on 40 it is showing 125 watts out on an inline meter with the K2

display showing 25 watts out.  So the actual forward power is way off from
the display and there is no control forward power on the K2.

And the receive of the K2 is affected by the power adjustment knob.  In the
high power section of the power knob the receive and noise floor drops a
couple of s units from the low power section of the power knob adjustment.
It seems to be much more sensitive in the low power setting than the high
power setting.

Prior to this rig number 3479 was a perfectly functioning radio.


To me - this is sounding like a software problem but I honestly do not know
were to begin.  Any ideas or anyone who may have had similar problems
offering suggestions on some direction would sure be appreciated.


Thanks

Paul K8QT
Serial Number 3479

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[Don Wilhelm-3]

Paul,

Something is loose - perhaps an unsoldered connection.  Unfortunately,
things like that are difficult to locate, especially if the problem goes
away when you touch something - sometimes you think it is fixed only to find
it back later.

Since it reacts when you touch most anything on the Front Panel, I sould
examine the front panel board first (and perhaps even re-flow the
soldering).  The control board would be the second suspect since it is right
there close to the Front Panel.  Of course, check the connectors between the
front panel and RF board and also the control board connectors.

73,
Don W3FPR

> -----Original Message-----
> From: [hidden email]
> [mailto:[hidden email]]On Behalf Of Paul
> Sent: Thursday, December 14, 2006 10:37 AM
> To: [hidden email]
> Subject: [Elecraft] Progressive Problem......
>
>
> Board Members,
>
> K2 Serial Number 3479 needs help.   Over the past couple of months an odd
> little quirk developed.  When turned on the rig would do one of two
> things...... after about 10-20 seconds the rig would jump from filter
> setting SF1 to SF4.  This would happen by itself after being
> turned on and
> started to warm up.  Occasionally - it did not happen in the first 10-20
> seconds BUT it would happen when I would touch the volume control
> or power
> control or rf gain control or any of the push button on the front
> panel.  So
> either way it would (by itself or with me adjusting one of the
> control) it
> would move from SF1 setting to the SF4 setting.  It had done this
> for about
> a two months.
>
> I let it go because I figured it was just a odd thing that developed with
> the rig.
>
> NOW the rig is doing this and I have lost control of the power
> output.  On
> 10 meters with the power output the display reads 1 thru 100
> watts out but
> in reality with a meter in line the output is only 5 watts or 100 watts
> depending if I am in the low power (10 watts) or in the high power (100
> watt) section of the power adjustment control.  There is nothing
> in between.
> It gives 5 watts or 100 watts - depending only on if the dial is
> in the high
> or low setting section.  No control even though the K2 display is showing
> various settings different than 5 watts or 100 watts.
>
> Further ... On 20 40 and 80 meters during my initial test the output was
> only 20 watts.  Today  I checked it and 20 is showing 100 watts
> out with no
> control and on 40 it is showing 125 watts out on an inline meter
> with the K2
> display showing 25 watts out.  So the actual forward power is way
> off from
> the display and there is no control forward power on the K2.
>
> And the receive of the K2 is affected by the power adjustment
> knob.  In the
> high power section of the power knob the receive and noise floor drops a
> couple of s units from the low power section of the power knob
> adjustment.
> It seems to be much more sensitive in the low power setting than the high
> power setting.
>
> Prior to this rig number 3479 was a perfectly functioning radio.
>
>
> To me - this is sounding like a software problem but I honestly
> do not know
> were to begin.  Any ideas or anyone who may have had similar problems
> offering suggestions on some direction would sure be appreciated.
>
>
> Thanks
>
> Paul K8QT
> Serial Number 3479
>
> _______________________________________________
> Elecraft mailing list
> Post to: [hidden email]
> You must be a subscriber to post to the list.
> Subscriber Info (Addr. Change, sub, unsub etc.):
>  http://mailman.qth.net/mailman/listinfo/elecraft
>
> Help: http://mailman.qth.net/subscribers.htm
> Elecraft web page: http://www.elecraft.com
> --
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> Checked by AVG Free Edition.
> Version: 7.5.432 / Virus Database: 268.15.18/585 - Release Date:
> 12/13/2006 11:49 AM
>

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Checked by AVG Free Edition.
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6:13 PM

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