[Elecraft] Fwd: AW: K3 KPA3 bias adjust

[Don Wilhelm]

Chuck,

The instruction cited was for a 400-500 ma rise TOTAL (not per device). 
So I conclude your bias is set too high or there is a problem in the 
bias circuit.

73,
Don W3FPR

On 3/7/2019 9:31 AM, hawley, charles j jr wrote:
> Thanks for the info. Using xmit for the low power amp and then going to the high power amp shows a difference of 1.05A. So my devices are showing about 500+ ma each. In the ball park.
> Thanks so much for the reply.
> 
> Chuck Hawley
>   c-hawley at illinois.edu
> 
>   Amateur Radio, KE9UW
>   aka Jack, BMW Motorcycles
> 
> ________________________________
> From: elecraft-bounces at mailman.qth.net <elecraft-bounces at mailman.qth.net> on behalf of Mike Harris via Elecraft <elecraft at mailman.qth.net>
> Sent: Thursday, March 7, 2019 5:43 AM
> To: elecraft at mailman.qth.net
> Subject: [Elecraft] Fwd: AW: K3 KPA3 bias adjust
> 
> Hi,
> 
> Forwarded a 2009 email exchange for your info. I have NOT tried this so
> use with care and at your own risk.
> 
> Regards,
> 
> Mike VP8NO
> 
> 
> -------- Forwarded Message --------
> Subject: AW: [Elecraft] K3 KPA3 bias adjust
> Date: Sat, 3 Jan 2009 19:46:55 +0100
> From: Koppendorfer Klaus <KK at ccf.net>
> To: Jan Erik Holm <sm2ekm at telia.com>
> CC: Elecraft at mailman.qth.net <Elecraft at mailman.qth.net>
> 
> Locate the BIAS pot at the front of the KPA3, between the heat sink and
> the KPA3 shield. Note what the display current is in the VFO B readout
> when you tap the Display button and turn the VFO B knob to the current
> readout. In RX, it should be 1.0A or so.   In XMIT (not TUNE), it should
> be about 1.90 to 2.0A when the Power knob is set to 12w or above so the
> KPA3 is made active (but there is no RF output since XMIT is used). Or
> you can press the PTT button but do not speak.
> 
> If there is much more current than this, set the BIAS pot to minimum
> (fully counter clockwise). Then tap XMIT (not TUNE) and note what the
> current is in VFO B's readout. Slowly turn up the BIAS pot until you see
> 400-500mA more current that was seen with the BIAS pot at minimum.
>