The GPS-4 manual is on my web site. Search for GPS-4 http://www.ko4bb.com/cgi-bin/manuals.pl
Didier KO4BB > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Scott A Sybert > Sent: Saturday, June 28, 2008 3:24 PM > To: [email protected] > Subject: [time-nuts] FS: Brandywine GPS-4 - Qty: 7 available > - AdditionalSpecs > > Hi Guys... > > A number of you have been inquiring about additional > specifications on these units. Here's what I've found. It > looks like it may address some of your questions. I think > this is all I'm going to be able to turn up on these units. > Most of the data we had on them is long gone. > > Scott > > ------------------------------- > > > 1. Section 2.2.1: could you spec the min/max VOH/VOL and IOH/IOL > > > of the PPS output. > > Voh min 2.4V > > Vol max 0.4V > > > > > > > > 2. Section 2.2.2: the amplitude of the 10MHz is at least 1Vrms > > > in 50ohm: please also spec a maximum. > > > > 1.5V RMS Max > > > > > > > > 3. Section 2.2.3: could you spec the min/max VOH/VOL > and IOH/IOL > > > of the 19.6608MHz output. > > 50pf load > > Voh 4.5V min > > Vol max 0.4V > > Iol/Ioh ±25mA > > Load 50 ohms > > Voh 2.4V min > > Vol 0.4V max > > > > > > 4. Section 2.2.3: could you spec the jitter and the wander of > > > the 19.6608MHz output. (I am concerned about the frequency > > > variation over a 1-second duration.) > > Short term stability > > Square root of Allan Varience: 1x10-10, tau = 1 second > > Phase jitter: 100ps > > > > > > > > 5. Section 2.3.1: could you spec the min/max VIH/VIL > and IIH/IIL > > > of the Reset input. > > Voh min 4.5V > > Vol max 0.4V > > Iol<0.1ma > > Ioh 1mA max > > > > > > > > 6. Section 2.7: I do not understand the open-collector pulled > > > to ground, then the next line mentions a max > pull-up voltage. > > > Please clarify. > > This is an output which is open collector, pull up through a > 1K resistor to 5 volts. "open collector pulled to ground" > was an incorrecte statment. > > > > > > 7. Section 2.7: there seems to be an inconsistency about the > > > active level of the "Fault" pin: it is active low here, but > > > active high in the table of section 2.9. > > > > > > 8. Section 2.7: please define the criteria for the Fault output > > > to be active. > > > > > > 9 Section 3.4: also a discrepancy between the text and the > > > table about the active level of the Fault output. > > > > > > 6. Section 2.7: I do not understand the open-collector pulled > > > to ground, then the next line mentions a max > pull-up voltage. > > > Please clarify. > > This is an output which is open collector, pull up through a > 1K resistor to 5 volts. "open collector pulled to ground" > was an incorrect statement. > > > > > > > User connection is to COLLECTOR of transistor (via 100R > internal protection). The user can connect this collector > through a resistive load to a positive voltage which has the > maximum specified (with reference to pin 5 GND at connector). > > > > When the GPS4 output is asserted (ie NO FAULT or TIME LOCKED) > the transistor is turned ON sinking current from the user's > positive supply through the users load and the 100R resistor > inside the GPS4 > > > > > 7. Section 2.7: there seems to be an inconsistency about the > > > active level of the "Fault" pin: it is active low here, but > > > active high in the table of section 2.9. > > > > > Pin 9 of the 9way Dtype socket is pulled LOW by the open > collector transistor for NO FAULT. > > The transistor is OFF in the case of a fault (which includes > lack of power) > > > > > 8. Section 2.7: please define the criteria for the Fault output > > > to be active. > > > > > > > There are 4 fault sources:- > > > > Processor cannot run (watchdog asserts fault output) > > > > 8 hours of no reception of satellites (eg faulty antenna) > > > > Frequency Error (GPS4 cannot control internal frequency > standard (OCXO) to track reference 1pps from GPS) > > > > DAC is near the end of its adjustment range (MAX 61440 MIN 4096) > > _______________________________________________ > 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.
