[EMAIL PROTECTED] made an utterance to the drakelist gang ---------------------------------------------------------------------- On Wed, 4 Jan 2006, Ron Wagner wrote:
> One big difference is that the AC3 has a set of resistors in the bias > line. Those resistors are jumper shorted out normally with a small > screw. Lifting the jumper short allows you to easily measure the idle > current (actually voltage across known resistance). Much easier then > trying to look at the fat needle against fat marking. > > You can measure the current on the resistor under the chassis too, and > should to make sure the finals are balanced. But to set the current > easily the AC3 was a gem. IMHO. You touched on something that I noticed when I was trying to align the bias current on my AC-3 (and haven't tried yet with AC-4)... I wound up leaving the screw connected and measuring the voltage off of the connection to the filter C (will have to review the schematic to tell you which one). Can this same trick be used on the AC-4 or is this an AC-3 only operation? I had to pull the bottom cover off of the AC-3 to do this - I couldn't make heads or tails of the TP-1 reading with the jumper screw removed. Thanks! -- 73 Jason N1SU http://n1su.com/ ---------------------------------------------------------------------- Submissions: drakelist@www.zerobeat.net Unsubscribe: [EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost: [EMAIL PROTECTED] - help in body of message Zerobeat Web Page: www.zerobeat.net - sponsored by www.tlchost.net ----------------------------------------------------------------------
