580 Bias Adjustment to Finals

From Ten-Tec Reflector August 27, 1996

Here is the proper procedure for final bias adjustment for the Delta 580 (not outlined in the operating manual).

On the bias board, turn R23 down to zero. Locate final amplifier board. Unsolder the large red B+ wire from the board. Unplug connector #57 turn it 90 degrees, replug in so only the blue wire from the connector is connected, leaving an open pin. Place an ammeter between the red B+ wire and this open pin. Adjust R17 on final amplifier board for 50 to 60 milliamps. Replug connector 57 correctly. Place ammeter between the red B+ wire and the spot it was unsoldered from. Adjust R23 on bias board for 500 milliamps. Reattach red B+ wire.

If any of this is unclear, please contact Garland Jenkins in Ten-Tec service at (423) 428-0364 M-F 8-4 Eastern.

73, Scott Robbins KY2P, Ten-Tec