Bert Hyman wrote:
In

JIMMIE wrote:

I bought 3 old cell phones at a yard cell the other day to tinker
with. These are GPS equipped. I was wondering it would be possible to
take a signal off of these I could use as a time reference. At work
we have such a reference that supplies 10Mhz, 1Mhz 1 Hz and I think
there are other frequencies. I opened one up and dont have a clue to
what any of the chips do. Any help would be appreciated.

Rather than beating your head against a wall trying to figure that
out, why not look into a GPS module? You can get a Garmin GPS15 for
less than $50.

https://buy.garmin.com/shop/shop.do?cID=157

I'm sure there are similar products from other makers.

Bert,
My take on your plan is that it's a losing battle. Cell phones are not
really designed with frequency standard capabilities in mind, and it's
rather far-fetched to think that you could easily find a 10.000000 MHz
frequency inside a cell phone. Even if you could find a stable reference
frequency inside a cell phone, you would likely need to build a good bit of
circuitry to get it back to 10 MHz.

I suggest that you search for Thunderbolt GPS on Ebay. Made by Trimble, the
units are GPS-based frequency standards that output 10 MHz and 1PPS signals.
They were built for the cellular industry, but unlike the cell phone, their
lot in life was to be a real frequency standard.
You can find them for approx. $100-$150 USD on Ebay. They are quite
reliable and are ready to run. You only need a GPS antenna and a PC with a
serial port to run them. After getting them set up with your PC, you can
disconnect the PC and it will run unattended. The software is free.
--
David
dgminala at mediacombb dot net