12-23-2018, 10:19 AM
Ed
Thanks. I'm thinking the same thing.
I believe I will reinstall the (otherwise untouched) oscillator coil today and concentrate on micas instead. It really doesn't bother me if I can't get the oscillator to track perfectly.
I can get a 4300 pF mica from Mouser but boy, are they pricey...only $8.91 EACH for a 5%, $10.26 EACH for a 1%. Since 4500 is no longer a standard value, I thought I would start at 4300. I could always add 100 pF or so in parallel if needed.
I have replacements for the 50 pF. (I think.)
*****
The more I look at the schematic, the more I think I should reduce the value of C9 (50 pF). It is connected directly to the trimmer that is all the way out...and to C band oscillator coil section L6. I think I should get a 4300 pF and a 200 pF, connecting in parallel to achieve 4500 pF. (Or maybe a 2000 and 2500 pF).
I'll see what I have on hand before ordering anything, although I'm pretty sure I don't have any such large value micas.
Thanks. I'm thinking the same thing.
I believe I will reinstall the (otherwise untouched) oscillator coil today and concentrate on micas instead. It really doesn't bother me if I can't get the oscillator to track perfectly.
I can get a 4300 pF mica from Mouser but boy, are they pricey...only $8.91 EACH for a 5%, $10.26 EACH for a 1%. Since 4500 is no longer a standard value, I thought I would start at 4300. I could always add 100 pF or so in parallel if needed.
I have replacements for the 50 pF. (I think.)
*****
The more I look at the schematic, the more I think I should reduce the value of C9 (50 pF). It is connected directly to the trimmer that is all the way out...and to C band oscillator coil section L6. I think I should get a 4300 pF and a 200 pF, connecting in parallel to achieve 4500 pF. (Or maybe a 2000 and 2500 pF).
I'll see what I have on hand before ordering anything, although I'm pretty sure I don't have any such large value micas.
--
Ron Ramirez
Ferdinand IN