Still fighting some small bugs in the new amp this morning, does this sound
like a symptom of the bias being too low??
When i key up with no drive the plate idles at about 90-100mA, and the grid
goes slightly negative, just enough to pull the needle a hash mark width below
the zero on the scale. As i apply drive the plate comes up to about 400mA and
the grid starts to come above zero, but i have to literally YELL on SSB to get
the grid to come up and see full output. I tried some CW on it last night and
its making full output there. Also at the suggestion of some on here i tried
applying drive on FM and the grid came up to 100mA and the plate stayed around
400mA yet.
So from the info i can find online, in the handbooks, picking others brains,
etc.. It would seem i still have a bias issue here as its only amplifying on
the voice peaks on SSB. I dug through my drawers and didn't have the parts to
do the mod for higher bias on the Triode Board so i ordered some zeners from
Mouser today and i will get that done when they arrive and see if i can further
adjust the bias and get the idle current down some more as well.
What do you guys think?? Starting to realize once again why i like building
stuff, learning is fun!
73,
Scott
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