Hi; Is your coax 50 or 75 ohm? Is it microwave rated? and have you tried changing coax length? None of these should be a major factor but could make a difference. Best Wishes; Thomas Knox
> From: shali...@gmail.com > Date: Mon, 30 Jul 2012 13:46:40 -0500 > To: time-nuts@febo.com > Subject: Re: [time-nuts] Active antennas for a Thunderbolt... > > Chuck, > > I have one of the original red box TB. It came with the Trimble Bullet > antenna that is specified in the TB datasheet. > > The antenna works but gives extremely poor results. The TB works much better > with the Symmetricom antenna that is sometimes available on eBay. > > The Bullet antenna is usable with other GPS receivers, so I know it is not > bad. Its just a poor match for the TB. > > Didier KO4BB > > > Chuck Harris <cfhar...@erols.com> wrote: > > >Ok, I'm getting a little puzzled. I have a TB that came from one of > >the early groups sold by John Ackermann and TVB as part of the TAPR > >buy. > >It works nicely, but like all TB's, it is deaf as a post, and needs a > >high gain antenna.... When I first got the TB, I tried it with a > >Motorola > >hockey puck antenna, with about 17db gain, and if it is outside in the > >clear, it works nicely... but LH shows the satellites signals are all > >down in the mud. > > > >...So... > > > >I bought the active antenna that the TB data sheet said belonged with > >the TB, a 24045-10 bullet antenna, and *NO* satellites are visible.. > >the antenna is dead. > > > >I'm no stranger to getting cheated on things I buy, so I chalked it up > >to bad luck, and put my Motorola hockey puck antenna back on my TB. > > > >...Then.... > > > >A couple of days ago another active antenna became available, a > >Micro Pulse 1934NW/C 50db antenna from a DATUM INC GPSDO. I checked > >its data sheet, and it powers off of +5V @ 38ma, so I bought it, > >hooked it up to my TB, and again *NO* satellites are visible... the > >antenna is dead. > > > >I put a "T" in the line, and the voltage heading up to the antenna is > >around +4.5V... The spec sheet says it will work down to +3V. > > > >Am I doing something wrong here? Or am I just unlucky? > > > >-Chuck Harris > > > >_______________________________________________ > >time-nuts mailing list -- time-nuts@febo.com > >To unsubscribe, go to > >https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > >and follow the instructions there. > > -- > Sent from my Motorola Droid Razr phone with K-9 Mail. Please excuse my > brevity. > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.