Yes, there is a trigger. Here is the schematic.
http://mysite.verizon.net/nonobar/circuit.jpg
There's actually a capacitor coupling the trigger pulse into the diodes (I
forgot to show it).
The two bias resistors going to -15 are critical as are the commutating
capacitors (not shown) across the 3.3k resistors.
It wants to work, but in a very unstable manner. I think I simply may be
taxing the rise times of the 3904s.
Pete
"Barrie Hiern" wrote in message
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wlYd.52687$xt.52461@fed1read07...
Do you have a trigger before the flip-flop???
"Peter Barbella" wrote in message
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Hello Gang,
I've got a crystal (7.155 mhz) that I need to use at half frequency. I
decided to pump it into a flip flop, but I'm having an awful time using
2n3904 transistors. The triggering seems to be a very challenging design
issue.
Anybody have any thoughts, (or other ideas for halving frequency)?