Curt, FWIW, I had a TR3 that did the same thing years ago. Put in a new fuse and it continues for years. 73 Ron WD8SBB
--- On Tue, 4/27/10, Curt <[email protected]> wrote: > From: Curt <[email protected]> > Subject: [Drakelist] T-4X filament fuse brunout and other strange behavior > To: [email protected] > Date: Tuesday, April 27, 2010, 10:16 PM > I had a surprising experience today > when turned it, lights briefly came on then turned > off. Turned out the filament fuse ( evidently the > original ) had blown. Thinking maybe a tube filament > had shorted, I checked current draw, 5 amps peak at turn on > dropping to about 2 after warm-up. The fuse is an 8 > amp fuse, and seem to recall fuses aren't quick to blow > unless current is about 150% of the rating. > > So, does this just sound like a tired old fuse finally > giving up, or is there something else to look into? > > Also, the plate current behavior seems more sensitive to > drive than it used to be. On 40M, about 1/4 turn to go > to 150 ma, then a very small amount more drive rotation > causes the plate current to jump up to 250 ma. Efficiency > doesn't seem as good as it once was either. 150ma used > to show 40W on the tuner output meter, now about 25W. > Bias cuurent set to 70 ma. PA tubes dying? Driver > dying? both? > > 73, Curt KB5JO > > _______________________________________________ > Drakelist mailing list > [email protected] > http://mailman.zerobeat.net/mailman/listinfo/drakelist > _______________________________________________ Drakelist mailing list [email protected] http://mailman.zerobeat.net/mailman/listinfo/drakelist
