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
newswlYd.52687$xt.52461@fed1read07...
Do you have a trigger before the flip-flop???

"Peter Barbella" wrote in message
news:_VkYd.142$qN3.78@trndny01...
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)?