Bill, Trimble sells the Bullet antenna that is designed for their timing receivers. I have one and it works fine. I believe it is the same grade as the HP/Symmetricom antenna (filtered/amplified).
You may be able to find one on eBay. Didier KO4BB Bill Janssen said the following on 06/02/2007 07:39 PM: > A friend of mine just picked up a Z3801 GPS receiver without the > necessary antenna. > > I know this has been discussed recently but am wondering what the > recommended (cheap but usable ) antenna would be. I want to give him a > recommendation or two. The antenna has to be a 5 Volt version to match > the Z3801A _______________________________________________ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts