RadioBanter - View Single Post

February 21st 04, 05:20 AM

On Fri, 20 Feb 2004 09:56:22 GMT, (Mike W) wrote:

Mice one Jim.
1. buy your PAL programmer
2. buy your PAL
3. learn how to obtain the required function
4. burn the PAL and discover it does'nt work
5. while patience lasts go to 2. wend
6. revert to PLL

Well, true... Happens I have access to that sort of thing, but I do see
your point.

Another approach might be to divide by 5 and then you can double twice
with a couple of chips, and then divide by 2 to get the 50% duty cycle.

A PLL system works, but for something this simple a couple of generic glue
logic IC's will serve the purpose.

Let me see, it'd require a 7490, a hex inverter for some delay in the
multiplier, and a 7400 nand. If memory serves, that ought to do it.

Jim Pennell
N6BIU