Re: [time-nuts] James Knights ovenized crystal
When I was working on military electronics in the 60s, crystals in ovens often had octal sockets. Inside the package there was a mechanical thermal switch on an aluminium casing around the crystal with a heater wrapped around it. Two pins will be the crystal, there may be more than one shield, two pins will run the heater, and you may have a pin from the switched side of the heating element to run the indicator lamp on the front panel. good luck with getting it going, Neville Michie On 07/03/2008, at 6:55 PM, Bill Bearden wrote: I have a JK device named a Thermystal. The label says 1000 KC 43 MMFD (any age clues there?:-)). So I'm guessing it's an ovenized parallel-resonant crystal which is (was?) on frequency with 43 pf in parallel. This is a fairly large unit, about 1.75 X1.25 X 3.25 inches. It has an ordinary octal plug on the bottom. Does anyone have any information on this or a similar unit? I've had no luck with Google. I especially would like to have the pin connections and oven voltage, and whether there is anything other than a crystal and oven in the box. If worst comes to worst, of course, I'll open it up and look. Thanks, Bill, WB6JVC ___ 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] Mounting GPS Antenna on Steel Roof
Well, I plugged my Oncore UT+ into my PC and it didn't work until I put a level shifter in... no damage but no data either. So far I've been lucky in that every device I tried that needed a level shifter wasn't damaged by the lack of one. The normal MAX232 type level shifters include an inverter. So even if the voltage levels work without a level shifter, the signal will be upside down. -- These are my opinions, not necessarily my employer's. I hate spam. ___ 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] Mounting GPS Antenna on Steel Roof
Hal Murray wrote: Well, I plugged my Oncore UT+ into my PC and it didn't work until I put a level shifter in... no damage but no data either. So far I've been lucky in that every device I tried that needed a level shifter wasn't damaged by the lack of one. The normal MAX232 type level shifters include an inverter. So even if the voltage levels work without a level shifter, the signal will be upside down. To play safe, if one isnt sure that an inverter is required or not an exclusive OR can be used so that the signal can be inverted or not as required. Bruce ___ 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] Mounting GPS Antenna on Steel Roof
Quoth Hal Murray at 2008-03-07 19:59... The normal MAX232 type level shifters include an inverter. So even if the voltage levels work without a level shifter, the signal will be upside down. I'm building my test board with a hex inverter that I'm actually using to buffer the 1PPS signal. I've got spare gates on there so will build the board with jumpers so that I can invert or not invert (that is the question ;-)) As I'm working with two different types of GPS module, and may have others, my development board will have a lot of jumpers so that I can actually patch together something that works before I build the final boards - something that I feel necessary as I always seem to get my TX/RX mixed up! Just to clarify - I don't tend to use breadboards as they tend to take longer to debug than making a PCB. When PCBs are concerned, I tend to use SMDs wherever possible until such time as I find a way of making holes that a) doesn't break my drill every other hole and b) actually lines things up properly. (A CNC XY drill rig would be really nice - better buy a lottery ticket.) Cheers M -- Matthew Smith Smiffytech - Technology Consulting Web Application Development Business: http://www.smiffytech.com/ Personal: http://www.smiffysplace.com/ LinkedIn: http://www.linkedin.com/in/smiffy ___ 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] James Knights ovenized crystal
My search on Google did not turn up much, some pictures of james knights but not the one you have and a note that at least one octal oven had the crystal on pins 4 and 6. http://www.leedsradio.com/images-odds/JamesKnights_JK013S25.JPG http://www.leedsradio.com/images-odds/JamesKnights_JK02.JPG Crystal maybe pins 4 and 6 (http://www.qsl.net/wa2whv/wa2whv-am.shtml) If you could find a device that used this oven and the schematic then you would have what you need. - Original Message From: Neville Michie [EMAIL PROTECTED] To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Friday, March 7, 2008 2:47:00 AM Subject: Re: [time-nuts] James Knights ovenized crystal When I was working on military electronics in the 60s, crystals in ovens often had octal sockets. Inside the package there was a mechanical thermal switch on an aluminium casing around the crystal with a heater wrapped around it. Two pins will be the crystal, there may be more than one shield, two pins will run the heater, and you may have a pin from the switched side of the heating element to run the indicator lamp on the front panel. good luck with getting it going, Neville Michie On 07/03/2008, at 6:55 PM, Bill Bearden wrote: I have a JK device named a Thermystal. The label says 1000 KC 43 MMFD (any age clues there?:-)). So I'm guessing it's an ovenized parallel-resonant crystal which is (was?) on frequency with 43 pf in parallel. This is a fairly large unit, about 1.75 X1.25 X 3.25 inches. It has an ordinary octal plug on the bottom. Does anyone have any information on this or a similar unit? I've had no luck with Google. I especially would like to have the pin connections and oven voltage, and whether there is anything other than a crystal and oven in the box. If worst comes to worst, of course, I'll open it up and look. Thanks, Bill, WB6JVC ___ 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. Looking for last minute shopping deals? Find them fast with Yahoo! Search. http://tools.search.yahoo.com/newsearch/category.php?category=shopping ___ 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] NIST 'Quantum Logic Clock'
NIST 'Quantum Logic Clock' Rivals Mercury Ion as World's Most Accurate Clock http://www.physorg.com/news124035207.html -ch ___ 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] SVN-32
Those interested in the subject satellite should check the below page... http://groups.google.com/group/alt.satellite.gps/browse_thread/thread/d9ecefc77d23328e/fe7f019259416b60 Bruce ___ 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] SVN-32
From: [EMAIL PROTECTED] (Mike S) Subject: Re: [time-nuts] SVN-32 Date: Fri, 07 Mar 2008 18:17:03 -0500 Message-ID: [EMAIL PROTECTED] At 05:04 PM 3/7/2008, Bruce Lanning wrote... Those interested in the subject satellite should check the below page... http://groups.google.com/group/alt.satellite.gps/browse_thread/thread/d9ecefc77d23328e/fe7f019259416b60 That article was already cited here, and has a lot of inaccuracies. 1) SVN32/PRN32 was previously operational, and healthy, from 11 December 1992 until 28 January 1993, when its PRN was changed to 1. 2) GPS has always, and only, been defined for PRN numbers 1-32. There has never been a PRN 0. (see Table 3-I in http://www.navcen.uscg.gov/pubs/gps/icd200/ICD200Cw1234.pdf ) Even in the comments they have trouble to correctly interprent the ICD 200 document. They miss that the almenac data has dedicated slot for PRN1 to PRN32. A GPS that fails due to PRN32 is prepared fro PRN30 and PRN31 too... in parts at least, so specific bugs further down the line is to be expected. Apparently, some early military GPS receiver(s?) had software which incorrectly used zero based indexing for PRNs (i.e. 0-31 instead of 1-32), and so had problems with PRN32. That's why SVN32 was changed from PRN32 to PRN1 after being on for only a few weeks. See this memorandum: http://www.navcen.uscg.gov/gps/geninfo/50SW_GPSW_letter.pdf The PLGR and MAGR has this problem. You can implement PRN32 as PRN0 internally if you so wishes. As long as the mapping is correct all the way. The US Coast Guard have now sent out a warning on the GPS receiver issue: http://www.navcen.uscg.gov/lnm/Saab_R3_AIS_prob.htm SAAB have an updated list of messages here: http://www.saabgroup.com/en/AboutSaab/Organisation/SaabTransponderTech/News Some form of software upgrade is underway. Cheers, Magnus ___ 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] Mounting GPS Antenna on Steel Roof
The inverter is required because the Motorola GPS receiver uses TTL and the PC serial port uses RS232. RS232 uses a positive voltage of +3 to +25 volts to indicate a logic zero, and a negative voltage of -3 to -25 volts to indicate a logic one. Brian KD4FM Bruce Griffiths wrote: Hal Murray wrote: Well, I plugged my Oncore UT+ into my PC and it didn't work until I put a level shifter in... no damage but no data either. So far I've been lucky in that every device I tried that needed a level shifter wasn't damaged by the lack of one. The normal MAX232 type level shifters include an inverter. So even if the voltage levels work without a level shifter, the signal will be upside down. To play safe, if one isnt sure that an inverter is required or not an exclusive OR can be used so that the signal can be inverted or not as required. Bruce ___ 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] Mounting GPS Antenna on Steel Roof
Attached is a interface for an Oncore VP receiver. You will have to check - I believe the GT and UT use the same connections as the VP. Brian Kirby wrote: The inverter is required because the Motorola GPS receiver uses TTL and the PC serial port uses RS232. RS232 uses a positive voltage of +3 to +25 volts to indicate a logic zero, and a negative voltage of -3 to -25 volts to indicate a logic one. Brian KD4FM Bruce Griffiths wrote: Hal Murray wrote: Well, I plugged my Oncore UT+ into my PC and it didn't work until I put a level shifter in... no damage but no data either. So far I've been lucky in that every device I tried that needed a level shifter wasn't damaged by the lack of one. The normal MAX232 type level shifters include an inverter. So even if the voltage levels work without a level shifter, the signal will be upside down. To play safe, if one isnt sure that an inverter is required or not an exclusive OR can be used so that the signal can be inverted or not as required. Bruce ___ 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. Oncore Interface.pdf Description: Adobe PDF document ___ 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] Mounting GPS Antenna on Steel Roof
Quoth Brian Kirby at 2008-03-08 14:46... Attached is a interface for an Oncore VP receiver. You will have to check - I believe the GT and UT use the same connections as the VP. Thanks Brian - that's pretty close to what I've come up with apart from the fact that I'm putting isolation (TI ISO7231) between the receiver and the rest of the circuit and the receiver is powered by a MeanWell high-isolation DC/DC convertor. And I've got mine running right to left ;-) I've got a something very similar drawn up for my Trimble modules except that the isolation and level conversion is x2, for the two serial ports. Cheers M -- Matthew Smith Smiffytech - Technology Consulting Web Application Development Business: http://www.smiffytech.com/ Personal: http://www.smiffysplace.com/ LinkedIn: http://www.linkedin.com/in/smiffy ___ 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] Mounting GPS Antenna on Steel Roof
For isolation of digital signals such as RS-232 (before level translation), it's hard to find something more amazing than the Analog Device ADuM5241 http://www.analog.com/en/prod/0,2877,ADUM5241,00.html It's an SO-8 device, with two digital channels, isolated to 2500V (!) and a built-in power converter that delivers 5V @ 10mA. All in an SO-8 package. The power converter runs at 300 MHz. But wait, it costs $3 in 1,000 pcs quantity. They have other options in the same series, with more channels (in a larger package). After seeing that, the LTC 1535 from Linear Technology, which would be pretty amazing in it's own right, looks pretty dull: http://www.linear.com/pc/productDetail.jsp?navId=H0,C1,C1007,C1017,P1746 Didier KO4BB -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Matthew Smith Sent: Saturday, March 08, 2008 12:15 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Mounting GPS Antenna on Steel Roof Quoth Brian Kirby at 2008-03-08 14:46... Attached is a interface for an Oncore VP receiver. You will have to check - I believe the GT and UT use the same connections as the VP. Thanks Brian - that's pretty close to what I've come up with apart from the fact that I'm putting isolation (TI ISO7231) between the receiver and the rest of the circuit and the receiver is powered by a MeanWell high-isolation DC/DC convertor. And I've got mine running right to left ;-) I've got a something very similar drawn up for my Trimble modules except that the isolation and level conversion is x2, for the two serial ports. Cheers M -- Matthew Smith Smiffytech - Technology Consulting Web Application Development Business: http://www.smiffytech.com/ Personal: http://www.smiffysplace.com/ LinkedIn: http://www.linkedin.com/in/smiffy ___ 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. No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.5.516 / Virus Database: 269.21.6/1316 - Release Date: 3/6/2008 6:58 PM No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.516 / Virus Database: 269.21.6/1316 - Release Date: 3/6/2008 6:58 PM ___ 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.
