Setting the bias on an Rf amp

[Jesset1996.5]

I have a Kenwood TS 690s and a few other radios that need the bias re calibrated either due to age or have had there caps replaced. The manuals are not very descriptive of how i measure the current or have the wrong info all together.... 
Couldn't i just measure the idle current through the 12v power leads?
I have herd that some pa decks have a jumper specifically for this purpose but this isn't the case with the radio's i will be working on.
Thanks, Jesse J Trimble (AC8WP)

[LA7SJA]

Hi Jesse
According to the Transmitter Section Adjustment page 124 item 6 (HF final bias) in the service manual (http://www.radiomanual.info/schemi/TS450S_690S_serv.pdf) you should turn down the bias setting to min on  VR1 and VR2, record the total current and adjust the bias to the recorded current + 250mA with VR1 then adjust VR2 so that the total current is equal to the recorded current + 500mA.
The adjustment procedure of "a few other radios" is in their respective service manuals. Some radios have a link/bridge/connector that can be removed so that you can measure the current in line with the PA output transistors and others use this metode and some have a small resistor in serie (so that you can measure the voltage over the resistor and calculate the bias current) with the PA transistors.

73
Johan-Fredrik