Re: [time-nuts] XL-DC was Re: time-nuts Digest, Vol 127, Issue 33
I can confirm there are at least two common varieties of the XL-DC GPS RX board. One uses a normal GPS antenna (no down-converter, provides DC on the antenna line for an amp in the antenna, the typical antenna provided seems to be an AeroAntenna AT575 variety, but I suspect other antennas that are similar should be fine). The specific antenna part I have is: AT575-142TTW-TNCF-000-RG-41-NM It's been a while since I last decoded that part number but it's a very easily re-useable general use GPS antenna with an integrated RF amp. Works over a fairly wide range of DC supply voltages and claims a slightly higher gain than some other standard timing GPS ice cream cones. There are also versions of the GPS module for the XL-DC that use a GPS antenna with an integrated down converter that is actually physically part of the antenna provided. The down converter antenna is normally a single integrated unit. The part numbers I see on one I have handy are 140-614 (TrueTime) or Model 142-6150 on the Symmetricom label. I don't have any details for the voltages or whether there is a reference frequency provided for the down converter style receiver. I have seen some suggestions that they also had a dedicated down converter module that could be used with normal GPS antennas, but I don't have any details on that option. If you have a RX module that needs the converter antenna there should be a clearly visible little label indicating this on the module itself near the antenna connector. If you don't have that label the RX should work with most GPS antenna systems (and also with most antenna splitter systems too). -- Russell Al Wolfe wrote: I have an XL-DC and it has an internal GPS receiver in it. It supplies and monitors 5 volts to a BNC antenna jack for an external amplified GPS antenna. I don't know what the internal GPS engine is but doubt if it is anything special. The manual describes the down converter system as an option. Al, k9si Boy I ran out to mr google and did a search and now I am wondering if some versions of the xl-dc just used a plain old GPS antenna. It sure looks like that could be the case. The manual does say down converter. Maybe it changed over time. Regards Paul WB8TSL ___ 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.
Re: [time-nuts] XL-DC was Re: time-nuts Digest, Vol 127, Issue 33
Hi One important caution on antennas: The 575 is quite happy with anything from 5 to 18V as a feed voltage and only pulls 35 ma. There are antennas out there that don’t like voltages over 6V. There also are antennas on the market that pull well over 50 ma. If the “original” box sourced 12V to the antenna and triggers as “overload” around 50 ma, the 575 will work great with the box. If you plug a modern timing antenna (= 5V version) into the box the antenna may be damaged and / or the over current may trigger. There also are 3.3 V antennas out there, but they are rarely seen in timing applications (yet). Simply put - the 575 is a great antenna and it will work on a lot of stuff. The problem is not at all with the antenna. It’s with the stuff specified to work with it. You have no way of knowing if it’s a 12V gizmo or a 5V feed. The same issue can come up with downconverter feeds. They often put +12 on the feed to run the downconverter. It’s best to put a DVM on the feed before attaching a nice new $1,500 antenna to it …(or even a $20 one) Bob On Feb 27, 2015, at 1:11 PM, Russell Rezaian r.reza...@earthlink.net wrote: I can confirm there are at least two common varieties of the XL-DC GPS RX board. One uses a normal GPS antenna (no down-converter, provides DC on the antenna line for an amp in the antenna, the typical antenna provided seems to be an AeroAntenna AT575 variety, but I suspect other antennas that are similar should be fine). The specific antenna part I have is: AT575-142TTW-TNCF-000-RG-41-NM It's been a while since I last decoded that part number but it's a very easily re-useable general use GPS antenna with an integrated RF amp. Works over a fairly wide range of DC supply voltages and claims a slightly higher gain than some other standard timing GPS ice cream cones. There are also versions of the GPS module for the XL-DC that use a GPS antenna with an integrated down converter that is actually physically part of the antenna provided. The down converter antenna is normally a single integrated unit. The part numbers I see on one I have handy are 140-614 (TrueTime) or Model 142-6150 on the Symmetricom label. I don't have any details for the voltages or whether there is a reference frequency provided for the down converter style receiver. I have seen some suggestions that they also had a dedicated down converter module that could be used with normal GPS antennas, but I don't have any details on that option. If you have a RX module that needs the converter antenna there should be a clearly visible little label indicating this on the module itself near the antenna connector. If you don't have that label the RX should work with most GPS antenna systems (and also with most antenna splitter systems too). -- Russell Al Wolfe wrote: I have an XL-DC and it has an internal GPS receiver in it. It supplies and monitors 5 volts to a BNC antenna jack for an external amplified GPS antenna. I don't know what the internal GPS engine is but doubt if it is anything special. The manual describes the down converter system as an option. Al, k9si Boy I ran out to mr google and did a search and now I am wondering if some versions of the xl-dc just used a plain old GPS antenna. It sure looks like that could be the case. The manual does say down converter. Maybe it changed over time. Regards Paul WB8TSL ___ 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. ___ 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.
Re: [time-nuts] XL-DC was Re: time-nuts Digest, Vol 127, Issue 33
In my XL-DC's case, there must have been a downconverter built into the antenna (which I don't have), but there was an upconverter in the chassis which took the IF signal from the cable, and heterodyned it back up to L-Band. I haven't fiddled-around with the upconverter, but I suspect the IF was in the HF band. Overnight my XL-DC says the GPS is unlocked, but is tracking 6 satellites, so my troubles still persist... -Doug -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Russell Rezaian Sent: Friday, February 27, 2015 10:12 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] XL-DC was Re: time-nuts Digest, Vol 127, Issue 33 I can confirm there are at least two common varieties of the XL-DC GPS RX board. One uses a normal GPS antenna (no down-converter, provides DC on the antenna line for an amp in the antenna, the typical antenna provided seems to be an AeroAntenna AT575 variety, but I suspect other antennas that are similar should be fine). The specific antenna part I have is: AT575-142TTW-TNCF-000-RG-41-NM It's been a while since I last decoded that part number but it's a very easily re-useable general use GPS antenna with an integrated RF amp. Works over a fairly wide range of DC supply voltages and claims a slightly higher gain than some other standard timing GPS ice cream cones. There are also versions of the GPS module for the XL-DC that use a GPS antenna with an integrated down converter that is actually physically part of the antenna provided. The down converter antenna is normally a single integrated unit. The part numbers I see on one I have handy are 140-614 (TrueTime) or Model 142-6150 on the Symmetricom label. I don't have any details for the voltages or whether there is a reference frequency provided for the down converter style receiver. I have seen some suggestions that they also had a dedicated down converter module that could be used with normal GPS antennas, but I don't have any details on that option. If you have a RX module that needs the converter antenna there should be a clearly visible little label indicating this on the module itself near the antenna connector. If you don't have that label the RX should work with most GPS antenna systems (and also with most antenna splitter systems too). -- Russell Al Wolfe wrote: I have an XL-DC and it has an internal GPS receiver in it. It supplies and monitors 5 volts to a BNC antenna jack for an external amplified GPS antenna. I don't know what the internal GPS engine is but doubt if it is anything special. The manual describes the down converter system as an option. Al, k9si Boy I ran out to mr google and did a search and now I am wondering if some versions of the xl-dc just used a plain old GPS antenna. It sure looks like that could be the case. The manual does say down converter. Maybe it changed over time. Regards Paul WB8TSL ___ 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. ___ 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.
Re: [time-nuts] XL-DC was Re: time-nuts Digest, Vol 127, Issue 33
Hi, AT575-142TTW-TNCF-000-RG-41-NM Not all 575 antennas eat the same power. Its the RG in the part number above that specifies 4.2V to 15V DC power for the internal LNA. This is the most common option - but there are others. -- Björn div Originalmeddelande /divdivFrån: Bob Camp kb...@n1k.org /divdivDatum:2015-02-27 20:21 (GMT+01:00) /divdivTill: Discussion of precise time and frequency measurement time-nuts@febo.com /divdivRubrik: Re: [time-nuts] XL-DC was Re: time-nuts Digest, Vol 127, Issue 33 /divdiv /divHi One important caution on antennas: The 575 is quite happy with anything from 5 to 18V as a feed voltage and only pulls 35 ma. There are antennas out there that don’t like voltages over 6V. There also are antennas on the market that pull well over 50 ma. If the “original” box sourced 12V to the antenna and triggers as “overload” around 50 ma, the 575 will work great with the box. If you plug a modern timing antenna (= 5V version) into the box the antenna may be damaged and / or the over current may trigger. There also are 3.3 V antennas out there, but they are rarely seen in timing applications (yet). Simply put - the 575 is a great antenna and it will work on a lot of stuff. The problem is not at all with the antenna. It’s with the stuff specified to work with it. You have no way of knowing if it’s a 12V gizmo or a 5V feed. The same issue can come up with downconverter feeds. They often put +12 on the feed to run the downconverter. It’s best to put a DVM on the feed before attaching a nice new $1,500 antenna to it …(or even a $20 one) Bob On Feb 27, 2015, at 1:11 PM, Russell Rezaian r.reza...@earthlink.net wrote: I can confirm there are at least two common varieties of the XL-DC GPS RX board. One uses a normal GPS antenna (no down-converter, provides DC on the antenna line for an amp in the antenna, the typical antenna provided seems to be an AeroAntenna AT575 variety, but I suspect other antennas that are similar should be fine). The specific antenna part I have is: AT575-142TTW-TNCF-000-RG-41-NM It's been a while since I last decoded that part number but it's a very easily re-useable general use GPS antenna with an integrated RF amp. Works over a fairly wide range of DC supply voltages and claims a slightly higher gain than some other standard timing GPS ice cream cones. There are also versions of the GPS module for the XL-DC that use a GPS antenna with an integrated down converter that is actually physically part of the antenna provided. The down converter antenna is normally a single integrated unit. The part numbers I see on one I have handy are 140-614 (TrueTime) or Model 142-6150 on the Symmetricom label. I don't have any details for the voltages or whether there is a reference frequency provided for the down converter style receiver. I have seen some suggestions that they also had a dedicated down converter module that could be used with normal GPS antennas, but I don't have any details on that option. If you have a RX module that needs the converter antenna there should be a clearly visible little label indicating this on the module itself near the antenna connector. If you don't have that label the RX should work with most GPS antenna systems (and also with most antenna splitter systems too). -- Russell Al Wolfe wrote: I have an XL-DC and it has an internal GPS receiver in it. It supplies and monitors 5 volts to a BNC antenna jack for an external amplified GPS antenna. I don't know what the internal GPS engine is but doubt if it is anything special. The manual describes the down converter system as an option. Al, k9si Boy I ran out to mr google and did a search and now I am wondering if some versions of the xl-dc just used a plain old GPS antenna. It sure looks like that could be the case. The manual does say down converter. Maybe it changed over time. Regards Paul WB8TSL ___ 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. ___ 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.
