K3 intermittent transmit power

[Phillip Zminda]

My K3 -100 S/N 4385 has developed an intermittent transmit problem on CW. I operate very little SSB so can’t say if it happens on SSB. It seems that the transmit power as seen on the meter display drops to 0 on a character and then goes up to 100, even when running at 40 watts driving my amplifier, an ALS-600, modified with QSK. At first I blamed the amp and did check it out thoroughly, but see the problem even without it. I have checked all my coax connections, the amp keying keying connection, re-seated the power cable, tried both full and semi-qsk and both internal and external Winkeyer keying. I’ve seen this both with my antenna and with a dummy load. It doesn’t seem to matter which band I’m on. The problem seems to happen when the rig is first turned on and then may go away. I saw the problem when operating last night and when I tested the rig this morning on a dummy load it, re-occurred for a short while, then went away. A couple of weeks ago  ran SS CW with the K3 running QRP and didn’t notice the problem.

Before I box up the K3 and ship it to Elecraft, I am looking for ideas of what else to check. Although I built the K3 from a kit I haven’t had it open in years. I did send it to Don, W3FPR, to update the synthesizer boards and install the 2nd receiver about a year ago, but that was the last time the rig was opened up. The problem is very recent I am not sure if having 2nd RX will require much more disassembly in order to get to any connections related to the PA. I am rather hesitant to open the rig up. My workbench space is rather limited now and I don’t feel as confident with the dis-assembly as I was when I built the K3.

Any suggestions appreciated.

Thanks,

Phil N3ZP
______________________________________________________________
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]

[Don Wilhelm]

Phil,

If you have not done so already, crank up K3 Utility and do the Transmit
Gain calibration.
If that does not fix the problem, then contact Elecraft support.

73,
Don W3FPR

On 11/29/2017 9:40 AM, Phil Zminda wrote:
> My K3 -100 S/N 4385 has developed an intermittent transmit problem on CW. I operate very little SSB so can’t say if it happens on SSB. It seems that the transmit power as seen on the meter display drops to 0 on a character and then goes up to 100, even when running at 40 watts driving my amplifier, an ALS-600, modified with QSK. At first I blamed the amp and did check it out thoroughly, but see the problem even without it. I have checked all my coax connections, the amp keying keying connection, re-seated the power cable, tried both full and semi-qsk and both internal and external Winkeyer keying. I’ve seen this both with my antenna and with a dummy load. It doesn’t seem to matter which band I’m on. The problem seems to happen when the rig is first turned on and then may go away. I saw the problem when operating last night and when I tested the rig this morning on a dummy load it, re-occurred for a short while, then went away. A couple of weeks ago  ran SS CW with the K3 running QRP and didn’t notice the problem.
>
______________________________________________________________
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]

[Cady, Fred-2]

Also, make sure you are not using ALC from the AMP to control the K3 output power.

73,

Fred KE7X


________________________________
From: [hidden email] <[hidden email]> on behalf of Don Wilhelm <[hidden email]>
Sent: Wednesday, November 29, 2017 9:52 AM
To: Phil Zminda; [hidden email]
Subject: Re: [Elecraft] K3 intermittent transmit power

Phil,

If you have not done so already, crank up K3 Utility and do the Transmit
Gain calibration.
If that does not fix the problem, then contact Elecraft support.

73,
Don W3FPR

On 11/29/2017 9:40 AM, Phil Zminda wrote:
> My K3 -100 S/N 4385 has developed an intermittent transmit problem on CW. I operate very little SSB so can’t say if it happens on SSB. It seems that the transmit power as seen on the meter display drops to 0 on a character and then goes up to 100, even when running at 40 watts driving my amplifier, an ALS-600, modified with QSK. At first I blamed the amp and did check it out thoroughly, but see the problem even without it. I have checked all my coax connections, the amp keying keying connection, re-seated the power cable, tried both full and semi-qsk and both internal and external Winkeyer keying. I’ve seen this both with my antenna and with a dummy load. It doesn’t seem to matter which band I’m on. The problem seems to happen when the rig is first turned on and then may go away. I saw the problem when operating last night and when I tested the rig this morning on a dummy load it, re-occurred for a short while, then went away. A couple of weeks ago  ran SS CW with the K3 running QRP and didn’t notice the problem.
>
______________________________________________________________
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]
______________________________________________________________
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]