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Old August 15th 03, 01:50 PM
Michael Black
 
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"Harry \(SM0VPO\)" wrote in message . ..
Hi all,
I am having a spot of bother with prescaler chips. Basically I need to find
one at the right price and availability. US$5 each is reasonable, but where
from? Is there one available that is not obsolete?

I live in Sweden and my local component shop is ELFA (Swedens answer to RS).
They don't sell ANY digital divider that operates above 50MHz, except for
the 74F163 and I cannot come up with a reliable interface circuit to couple
an oscillator into it at over 100MHz.

I found the MB501 (MC12022, SP8704) but it is obsolete and cannot find a
reliable source. I bought a couple, but that source dried up. All I need is
a divider chip that will accept a small signal up to 150MHz, is available,
cheap(ish) and will divide down to under 10MHz so that I can use CMOS to
process a synthesiser. A parallel-load synthesiser chip with in-built 150MHz
prescaler would do.

I have used "Teleport" to download over 50,000 pdf datasheets without any
luck. I have gone through most of them, but it takes a fair bit of time. If
anyone has a helpful suggestion I would appreciate it.

BR from Harry - SM0VPO

http://w1.859.telia.com/~u85920178/
harryvpo (at) hotmail (dot) com


If you can live with a larger and binary division, there would be
a prescaler that likely does work to that frequency limit in any
digitally tuned FM broadcast radio. I have not looked up the
upper frequency limit on these, but of course their needed range
isn't much lower than your upper limit. I don't have a specific
part number, I'm not even sure how much variety of ICs are used
in these applications, but just about any scrap digitally tuned
radio would offer up something. And if you need to find something
commonly available but not rely on scrounging, then open one
up and find the NTE replacement for the prescaler.

Michael VE2BVW