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KPA500 - Erratic behaviour of POWER ON/OFF switch

Martin Kratoska
 

Hello,

my KPA500 s/n 1565 has interesting issue. When switching ON, sometimes the amp does not fire up but bands are switched instead, mostly to 10 or 6 m. Also the TEMP button shows similar issue. Another touch the button helps, the amp responds as expected. When once ON, the amp works as usual.

Where to look for a culprit? Defective switch? A cold solder joint?

Many thanks for any advice.

73,
Martin, OK1RR

Ray Maxfield
 

Hi Martin……… I would look for a Software setting in the Amplifier for Start-up Delay or time out.

 

Ray wa6vab

 

From: Martin Kratoska
Sent: Wednesday, September 4, 2019 12:39 AM
To: Elecraft-K3@groups.io
Subject: [Elecraft-K3] KPA500 - Erratic behaviour of POWER ON/OFF switch

 

Hello,

 

my KPA500 s/n 1565 has interesting issue. When switching ON, sometimes

the amp does not fire up but bands are switched instead, mostly to 10 or

6 m. Also the TEMP button shows similar issue. Another touch the button

helps, the amp responds as expected. When once ON, the amp works as usual.

 

Where to look for a culprit? Defective switch? A cold solder joint?

 

Many thanks for any advice.

 

73,

Martin, OK1RR

 

 

 

Bob McGraw - K4TAX
 

I would first make sure all connectors are seated or exercised, specially those connected to the front panel.

73

Bob, K4TAX

On 9/4/2019 1:56 PM, Ray Maxfield wrote:

Hi Martin……… I would look for a Software setting in the Amplifier for Start-up Delay or time out.

 

Ray wa6vab

 

From: Martin Kratoska
Sent: Wednesday, September 4, 2019 12:39 AM
To: Elecraft-K3@groups.io
Subject: [Elecraft-K3] KPA500 - Erratic behaviour of POWER ON/OFF switch

 

Hello,

 

my KPA500 s/n 1565 has interesting issue. When switching ON, sometimes

the amp does not fire up but bands are switched instead, mostly to 10 or

6 m. Also the TEMP button shows similar issue. Another touch the button

helps, the amp responds as expected. When once ON, the amp works as usual.

 

Where to look for a culprit? Defective switch? A cold solder joint?

 

Many thanks for any advice.

 

73,

Martin, OK1RR

 

 

 

Tyler Suydam
 

I recommend checking the ribbon connectors inside the KPA500 as K4TAX suggested.

A year or so ago, I had similar erratic behavior and Elecraft support recommended I check the connectors...sure enough, re-seating one of them corrected the issue.

73 de Tyler, KC2LST

Bob Bennett
 

Mine does not come on occasionally. I have looked at 1) when shutting it down, make sure you switch it to standby first; 2) you may have to hold the on button down for a second or two; 3) sometimes I have to go to turn the circuit breaker off and on again (I have no idea why🤔)

nz2z

Bob McGraw - K4TAX
 

One point which is very clear in the manual.  When shutting the system down by the front panel ON button, allow the unit to run until the fan stops in order to bleed the supply down.   Always do this BEFORE operating the switch on the rear of the unit.  See the manual page 14,   " !IMPORTANT  "

Don't know if this has any relationship to the issues of concern, however I always do this in sequence and have not experienced any power up or power down artifacts.

73

Bob, K4TAX


On 9/5/2019 1:04 PM, Bob Bennett via Groups.Io wrote:
Mine does not come on occasionally. I have looked at 1) when shutting it down, make sure you switch it to standby first; 2) you may have to hold the on button down for a second or two; 3) sometimes I have to go to turn the circuit breaker off and on again (I have no idea why🤔)

nz2z