Re: V6.1 Blown output transistors and pcb trace #v6 #ubitxv6-help

Stan K3PW

I’m using the instructions at which is essentially what you have in your post, Raj, except for one detail.  These instructions say with RV2 and RV3 fully clockwise the current should be between 470 and 500ma.  Mine is more than that, my current draw is 540ma, 40ma high.  

I’m not sure if 540ma instead of a max of 500ma is a problem or not.  What I did was bring the total current draw after adjustment to 700ma (500+100+100) by adding 80ma with each resistor making a total increase in current of 160ma.   

Here are my questions - 
1. Does the 540ma current draw indicate a problem I should worry about before adjusting PA bias?
2. Is what I’ve done a reasonable adjustment, staying under 700ma for total current draw, or is it inadequate bias?
3. Would it be better to adjust the two resistors for 100ma increase each for a total current draw of 740ma?

I appreciate all comments and suggestions!

Stan K3PW

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