Hello Greg Many thanks for your response. At least I learned something...... Do you have any idea where I can get this part (GPS synchronizer Model 8901-1 ) ? Do you familiar with any suppliers of TRAKs old products , cause they do not produce it anymore .
Thanks again Regards, Alex On Thu, Dec 16, 2010 at 8:08 AM, Greg Burnett <[email protected]> wrote: > I bought the TRAK 8900-1 on eBay five years ago. Because the 8901-1 GPS > synchronizer module wouldn't lock, the seller sent me a replacement 8901-1, > but I was unable to get it to lock either. My system didn't come with an > antenna. One issue was that the system supplied 12VDC (instead of the more > common 5VDC) to the active antenna. TRAK wanted a "fortune" for their > replacement antenna, so that option was out. I finally figured out that, > apparently, the 8901-1 had a current sensing circuit in its power supply > for > external antenna. The circuit was apparently configured to disable lock > unless the antenna dc power supply current was within a specified "window". > My substitute antenna apparently didn't draw enough DC current to make the > circuit happy. So I ended-up soldering a 1k ohm resistor, on the board, in > parallel with the antenna connector, in order to "trick" the sensing > circuit > into its "good" window. That made it work, and it locked just fine. (Note: > I no longer have the 8900-1, so I'm going by memory regarding the 1k ohm > value.) > > I might still have the defective, 2nd 8901-1 GPS synchronizer around here > some place. But I just looked, and tentatively don't see it anywhere. I've > moved twice since I bought the TRAK, so it might be misplaced or hidden in > some box somewhere? > > Best, > Greg > > > ----- Original Message ----- > From: "Alex Imas" <[email protected]> > To: <[email protected]> > Sent: Tuesday, December 14, 2010 3:07 PM > Subject: [time-nuts] TRAK Model 8900-1 GPS Disciplined Freq Std > > > Hello > > I found Greg Burnett page with question about TRAK model and I have a > question, too. > Maybe you can help, where did you buy this unit cause I'm looking for GPS > synchronizer Model 8901-1 , for our Trak Modular Frequency/Time System > Model 8900-50 and TRAK stopped produce it > > > Best regards > Alex > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
