[Elecraft] [POSSIBLE SPAM] HI CURR indicator on K3S display

Fri Feb 4 11:20:07 EST 2022

I've eliminated the power supply as the problem.  Tried three different ones and see the same issue (long shot anyway... I use high quality supplies).  I did remove the 100W module and everything works perfectly fine, so the problem is confined to the LPA3...  The fact that I can't calibrate the gain at 50W (fine at 5W) tells me I may have a bad transistor.  Ordered a fist full of transistors... will take the module back to the USA and put it on one of my RF bench at work to diagnose it further.  Also have a spare LPA3 if all else fails.

Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ VP2EHZ

email:  bill at wjschmidt.com

-----Original Message-----
From: elecraft-bounces at mailman.qth.net <elecraft-bounces at mailman.qth.net> On Behalf Of Bob McGraw
Sent: Friday, February 4, 2022 10:07 AM
To: elecraft at mailman.qth.net
Subject: [POSSIBLE SPAM] [Elecraft] HI CURR indicator on K3S display

Well clearly one of the indications, radio or power supply, is incorrect.

Just checked mine:

TX @ 100 watts, radio display = 18.3 amps, Power supply = 19.0 amps.

Voltage:  Radio RX = 14.3, PS = 14.5.   Voltage:  TX Radio = 13.9v, PS =14.5v

If the power supply voltage drops during TX, the control circuit will attempt to produce 100 watts in which the current may increase.   Also, different bands at 100 watts will draw different amount of current during transmit.

I actually found with a 100 watt power setting on the radio, the actual output power was more than 120 watts.  (See the discussion on Power Calibration).  This would of course affect the current demand.

73

Bob, K4TAX

On 2/4/2022 2:16 AM, elecraft-request at mailman.qth.net wrote:
> Message: 4
> Date: Tue, 1 Feb 2022 18:12:38 -0600
> From: "Dr. William J. Schmidt"<bill at wjschmidt.com> 
> To:<elecraft at mailman.qth.net>
> Subject: [Elecraft] HI CURR indicator on K3S display 
> Message-ID:<[email protected]>
> Content-Type: text/plain;	charset="us-ascii"
>
> I remember some discussion about HI CURR issues and the causes here a 
> while ago.  I just noticed it on my radio.. Changing the display to 
> read amps, it indicates 21.6 amps, but the amp meter on the power 
> supply is only showing
> 10.1 amps.  The radio sensing circuit seems to be in error.  Anyone 
> else delt with this?
>
>   
>
>   
>
> Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ 
> PJ2/K9HZ VP2EHZ

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