to bias the amp. I will connect the probes to black and red.
And then turn trim pot 1 so the multimeter shows 39ma.
And turn thd trim pot 2 to get 39ma as well.
Am i right!
Thanks.
4 4 0 biad method
Moderators: pompeiisneaks, Colossal
Re: 4 4 0 biad method
Where did you get the number 39mA???
There are bias calculation instructions on the schematic. Use 5W as PaMAX. Va will be your actual measured plate voltage.
For example, the schematic shows plate voltage as 339V. So, .7*5/339=10mA. You would adjust each bias pot to give 10mV reading at TP1 and TP2. When you adjust the bias pot the plate voltage will likely change, so you need to repeat this entire procedure, ie, measure plate voltage, do the math, adjust the pot. Sometimes you may have to repeat several times until you no longer need to adjust the pots.
There are bias calculation instructions on the schematic. Use 5W as PaMAX. Va will be your actual measured plate voltage.
For example, the schematic shows plate voltage as 339V. So, .7*5/339=10mA. You would adjust each bias pot to give 10mV reading at TP1 and TP2. When you adjust the bias pot the plate voltage will likely change, so you need to repeat this entire procedure, ie, measure plate voltage, do the math, adjust the pot. Sometimes you may have to repeat several times until you no longer need to adjust the pots.