The AL-1500 uses the same metering board as the 1200 and 82, they both use
2 resistors because the full scale is 400ma on the grid. The AL-1500 has a
200ma FS so hence the one resistor. Your amp is correct. The AL-1500
usually runs about 20ma grid at 1500 out if the tube is real good. As the
tube gets older it draws more grid current. Sounds like your OK. The output
meter is very inaccurate, don't go by it. Lou
In a message dated 12/23/2010 4:05:15 P.M. Eastern Standard Time,
w7ry@inbox.com writes:
Merry Christmas!
I'm working on a AL-1500. I noticed that the is only one 1.5 Ohm resistor
in the plate metering circuit. The schematic calls for two 1.5 Ohm
resistors (R3 and R4).
The plate current seems just a bit high. With 1500 watts out, plate
current is about 975 ma @ 2900 volts. I really believe the amp is a bit more
efficient than this.
Ideas?
Thanks
73
Jim W7RY
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|