What would typical grid current be for an Alpha 87A running 1500w on 20 or 40m? My 87A gets up to 105 ma (Yellow LED) at times (into a very low SWR antenna or dummy load). Is this normal? WOuld the 3
Author: Mike Schatzberg <cherokeehillfarm@earthlink.net>
Date: Mon, 31 Dec 2007 12:10:18 -0500
About 30 mils per triode max key down. If your grid current shunt is ok, the tubes may be soft. 73, Mike W2AJI What would typical grid current be for an Alpha 87A running 1500w on 20 or 40m? My 87A g
Excessive grid current is the major failure mode of 3CX800A7 tubes. 60 mA per tube is the absolute maximum. I religiously tune my Titan 425's (two 3CX800A7's) so that the grid current for two tubes c
Eimac specs say 60 ma per tube absolute max. I see no meaningful increase over 20-25 ma. What is the reading into a known 50 Ohm RESISTIVE load? Id be concerned about the Alpha itself if it allows su
Author: "Larry P. Greenberg" <wa9mag@ameritech.net>
Date: Mon, 31 Dec 2007 16:09:18 -0600
Jerry, My 87A draws around 35 to 50 ma grid current for 1,500 watts out. Before installing AlphaMax, sometimes it would get into the yellow. Now, with AlphaMax it is more well behaved. I don't know m
Are you sure the Hi-Lo switch is in the Hi position? You'll get high grid current if it's in the Lo position, and it'll be tough to get full output. The switch should always be in the Hi position. Ty