On Tue, 18 Nov 2003 01:27:56 GMT, (J M Noeding)
wrote:

for my quite unstable counters I've got some 0.1ppm 9.6MHz VCXO's
(guaranteed over temperature range -20...+20°C), the problem is that
the original XO is 1MHz with 7490 divider, and now I need a divide by
96 downcounter. The VCXO drives a 74LS14, so it shouldn't be any fan
out problem, but I am not aware what is the readily available divider
to choose. The counter is mentioned on
http://home.online.no/~la8ak/m21.htm , but it is Norwegian text

Isn't the 74(LS)92 divide by 12 counter available anymore ? With an
addition of a 74(LS)93 divide by 16 counter (divide by 192 total), you
can get the required divide by 96 ratio, if you skip the independent
divide by 2 section from either the '92 or '93.

If you can not get the '92, get two '93 chips, let the first divide by
16 down to 600 kHz. Using only the divide by 8 part of the second '93,
detect the "6" count with a two input AND/NAND gate and reset the
counter. IIRC, the '93 contains a built in two input NAND gate in the
reset circuit, so these inputs needs only be connected to the two most
significant outputs of the divide by 8 counter. The required 100 kHz
output can be taken from the most significant output (it has a 66:33
output ratio). If you need 50:50 ratio, first divide by 8 in the first
'93, then by 6 in the second '93 and then by two in the independent
section in the first '93.

Paul OH3LWR