Hi Karl,

Good timing  for your message. I just finished a web page documenting
the GPS timing system I will be offering. The web page URL is
http://www.seismicnet.com/gps/. There you will find photos and some
documentation on the system, as well as the cost. 

The antenna I have is not weather proof and only has 10 feet of cable. I'm
not sure if it can drive 150 feet of cable with having 26 db of gain. One
thing you can do is place the receiver near the antenna and run a long
RS-232 cable. The baud rate between SDR and the GPS receiver is 9600. You
should be able to run a 3 wire shielded cable that long. All you need is
transmit, receive and 1 PPS lines + ground. You will need to power the
receiver using a power supply near it. The unit takes 7 to 40 vdc at a
250ma to power it. Maybe you could run a 4th wire for power. As long as
theres more then 7 volts at 250 ma at the other end, it should power the
unit just fine.

For the interface board I ended up laying out my own board. There were a
few things I didn't like about the TAPR board, and, I thought it would be a
good board too try and layout myself.  Being a simple board I thought I
would try out my hand at laying out a PC board. My brother laid out all of
my other boards. I used a program called WinBoard. I'm not very happy with
it. It constantly crashed or locked up but I finally made a board I was
happy with. All in all it turned out pretty good.

So far I have 4 units going to Italy and maybe 6 units to Portugal. I
bought 10 GPS receivers and had 15 blank interface cards made. The problem
is I haven't heard from my contact in Portugal and can't get a PO number
and shipping address. So if I don't here from him in a few days I would
like to sell the receivers I have ASAP since the cost is on my credit card. 

-Larry Cochrane
Redwood City, PSN

At 12:21 AM 7/3/99 -0700, you wrote:
>Greetings --
>
>The San Diego Museum of Natural History is interested in buying a GPS for
>timing for their seismometer, which will be running SDR.
>
>The GPS must accomodate an external active antenna that can be located on
>the roof, at then end of about 150 feet of cable.  Of course, cost is a
>factor too.
>
>Does anyone have any recommendations on a GPS I could suggest to the museum?
>
>
>Karl Cunningham
>La Mesa, CA.
>PSN Station #40
>karlc@.......


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