Re: [time-nuts] LORAN C shutdown
Correct, They are already at a price and size where they are making it onto light aircraft. An IN platform is life cycle cost competitive with a mechanical vertical/directional gyro pair and adding navigation is "just" (cheap apart from the RTCA DO-178 assurance) software. Echos of the end of Omega. The company I was working for had just added GPS modules to their Tracor Omega/VLF navigation systems. Unfortunately as the GPS was secondary to the Omega, they were not able to use them when the Omega was turn off. Robert G8RPI (MRAeS, day job avionics design engineer) --- On Mon, 9/11/09, Poul-Henning Kamp wrote: From: Poul-Henning Kamp Subject: Re: [time-nuts] LORAN C shutdown To: "Discussion of precise time and frequency measurement" Date: Monday, 9 November, 2009, 23:06 Don't overlook that laser/fiber "ring-gyros" will drop in price the patents expire and the predatory pricing ends: http://www.es.northropgrumman.com/solutions/mk39/assets/mk39.pdf As much as I have enjoyed playing with Loran-C, I would far rather have a shoebox-sized, totally autonomous dead-reckoning backup, with no lightning-prone antenna, than a Loran-C receiver. Doesn't help us timing guys, but we have Cesiums if we are really serious. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ 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] LORAN C shutdown
In a message dated 09/11/2009 23:24:27 GMT Standard Time, alan.me...@btinternet.com writes: There is a system in the UK that already does that and used digital TV as well I believe. The accurate nav is only really needed in coastal water and the phones cover most of those. Ain't many trees in the middle of the ocean either John, but we are working on it as a disguse for deep sea oil drilling platforms :-)) Sounds like a job for..Decca Navigator Man :-) regards Nigel GM8PZR ___ 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] Oscillator for service monitor
A friend of mine is looking for a suitable replacement for the timebase in his Motorola S1327A service monitor. Here is the description he sent me for the existing oscillator. 1 Mhz Oscillator. Made by: Monitor PO of Pasadena, CA. Mfg Date 05/73 Heater is 115VAC. Osc power is 30VDC (+15 and -15). Can is 1.5 inches square. 3.75 inches long. Has an 8 pin Octal Socket on one end. Adjusting cap on other end. Can anyone suggest a suitable substitute? According to my friend, replacement units are no longer available and other, used units are usually also defective. ___ 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] Oncore glitch?
I've been asked if anyone noticed an iLotus / Motorola Oncore or M12 GPS receiver glitch a week ago (Wednesday 5 Nov at about 1900Z)? (no need to reply if your GPS receivers kept ticking; I'm just looking here for reports of any signal or tracking anomaly at the time in question) Thanks, /tvb ___ 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] LORAN C shutdown
On the other hand... With GPS-aiding its argued that high performance INS-systems are not needed. The same performance will be reached with a low cost GPS and a mid to low performance inertial system. So I doubt we will have low cost high performance intertial sensors anytime soon. -- Björn > Don't overlook that laser/fiber "ring-gyros" will drop in price the > patents expire and the predatory pricing ends: > > http://www.es.northropgrumman.com/solutions/mk39/assets/mk39.pdf > > As much as I have enjoyed playing with Loran-C, I would far rather > have a shoebox-sized, totally autonomous dead-reckoning backup, with > no lightning-prone antenna, than a Loran-C receiver. > > Doesn't help us timing guys, but we have Cesiums if we are really > serious. > > -- > Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 > p...@freebsd.org | TCP/IP since RFC 956 > FreeBSD committer | BSD since 4.3-tahoe > Never attribute to malice what can adequately be explained by > incompetence. > > ___ > 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] Oncore glitch?
I don't remember what day it was but last week I looked at my TAC32 program and noticed it had lost lock. It showed no satellites tracked. I restarted TAC32 and all was well. I use a Motorola Oncore and thought it might be something to do with daylight saving time changing. Garren -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Tom Van Baak Sent: Tuesday, November 10, 2009 11:29 AM To: Discussion of precise time and frequency measurement Subject: [time-nuts] Oncore glitch? I've been asked if anyone noticed an iLotus / Motorola Oncore or M12 GPS receiver glitch a week ago (Wednesday 5 Nov at about 1900Z)? (no need to reply if your GPS receivers kept ticking; I'm just looking here for reports of any signal or tracking anomaly at the time in question) Thanks, /tvb ___ 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] Oncore glitch?
I noticed a glitch at about 0100Z on 11/5/09 with a Fury. Unit has been tracking within +-10ns for many months, and then suddenly jumped to -40ns or so and recovered. Not sure if it lost lock or was in holdover. I wasn't monitoring it with GPScon prior to the event (I had rebooted the vm that it was running on and forgot to restart GPScon). By happenstance I restart it and noticed the large TI error. There was also some noise on outa...@outages.org about GPS errors around the same time. Scott On 11/10/2009 1:28 PM, Tom Van Baak wrote: I've been asked if anyone noticed an iLotus / Motorola Oncore or M12 GPS receiver glitch a week ago (Wednesday 5 Nov at about 1900Z)? (no need to reply if your GPS receivers kept ticking; I'm just looking here for reports of any signal or tracking anomaly at the time in question) Thanks, /tvb ___ 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] 5370B PROM
My 5370B PROM turns out to be fine (there was some operator error) I picked up a DATA I/O 201 programmer and some NOS windowed MOT MCM68764C to have some backups (this was probably overkill, since I have never actually seen a failed hp counter from ROM failure) A newly burned MCM68764C appears to work perfectly. The programmer reports SUMCHECK 7387 for U3, 5370B Ser. No. 2438A 01154 The programmer can report in the following formats: INTEL INTELLEC 8, INTEL MCS-86 HEX, MOTOROLA EXCERCIS, MOTOROLA EXORMAX, and TEKTRONIX HEX I can read these formats to a text file using a Windows terminal emulator to save them to a file, however, I do not know how to make the ROM Image. I was hoping to be able to say something about the ROM version, but I do not know how to compare the files I get to the available 5370B ROM image? The DATA I/O 201 does not appear to directly save the binary file. I can supply a few replacement 5370B ROMs at cost plus shipping if anyone needs one. Regards, Joe ___ 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] LORAN C shutdown
Hi Bjorn, This depends on what you call high performance. The normal definition of "high performance" in relation to IN is low drift with time. Even "cheap" fibre optic gyro based IN platforms can perform as well as the early airline standard mecanical units. GPS does not provide attitude or heading information (I'm ignoring specialist multi antenna differential set ups, these are not normal or mature systems). This information is needed in real time to fly the aircraft in IMC (low visibility) or on autopilot. Either attitude and directional gyros or an IN platform are still needed and IN is becoming the norm. There are also MEMS units that are making inroads in the light aviation market, especially in the USA. GPS (or to be more accurate GNSS) is only part of the system, all be it a very important one. Robert G8RPI. --- On Tue, 10/11/09, b...@lysator.liu.se wrote: From: b...@lysator.liu.se Subject: Re: [time-nuts] LORAN C shutdown To: "Discussion of precise time and frequency measurement" Date: Tuesday, 10 November, 2009, 19:29 On the other hand... With GPS-aiding its argued that high performance INS-systems are not needed. The same performance will be reached with a low cost GPS and a mid to low performance inertial system. So I doubt we will have low cost high performance intertial sensors anytime soon. -- Björn > Don't overlook that laser/fiber "ring-gyros" will drop in price the > patents expire and the predatory pricing ends: > > http://www.es.northropgrumman.com/solutions/mk39/assets/mk39.pdf > > As much as I have enjoyed playing with Loran-C, I would far rather > have a shoebox-sized, totally autonomous dead-reckoning backup, with > no lightning-prone antenna, than a Loran-C receiver. > > Doesn't help us timing guys, but we have Cesiums if we are really > serious. > > -- > Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 > p...@freebsd.org | TCP/IP since RFC 956 > FreeBSD committer | BSD since 4.3-tahoe > Never attribute to malice what can adequately be explained by > incompetence. > > ___ > 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] LORAN C shutdown
Hi Robert, High performance - for me - is 'navigation grade' wrt intertial systems. Your terminology is somewhat strange to me. 'IN' is that short for INertial or Inertial Navigation? There are (used to be) two basic types of intertial navigation systems; platform systems, where a number of gimbals with help from the gyros keep the central accelerometer platform at a constant orientation. The other type is strapdown systems, where gyros and accelerometers are mounted fixed within the INS box. High performance mechanical rotating gyros are associated with platform systems. Ring laser gyros and fiber optic gyros are typically strapdown, which completely dominate modern navigation. I doubt that your "cheap" FOG IN platform really is a platform system. I also very much doubt that these FOG systems perform as well as older mechanical platform inertial navigation systems! If you compare with vertical gyro-types, those are for aircraft control, not for navigation. Any IMU integrated with GPS/GNSS provides complete attitude information on moving platforms. There are certified pure GNSS heading sensors on the marine and other markets. -- Björn > Hi Bjorn, > This depends on what you call high performance. The normal definition > of "high performance" in relation to IN is low drift with time. Even > "cheap" fibre optic gyro based IN platforms can perform as well as the > early airline standard mecanical units. GPS does not provide attitude or > heading information (I'm ignoring specialist multi antenna differential > set ups, these are not normal or mature systems). This information is > needed in real time to fly the aircraft in IMC (low visibility) or on > autopilot. Either attitude and directional gyros or an IN platform are > still needed and IN is becoming the norm. There are also MEMS units that > are making inroads in the light aviation market, especially in the > USA. GPS (or to be more accurate GNSS) is only part of the system, all be > it a very important one. > > > Robert G8RPI. > > > --- On Tue, 10/11/09, b...@lysator.liu.se wrote: > > > From: b...@lysator.liu.se > Subject: Re: [time-nuts] LORAN C shutdown > To: "Discussion of precise time and frequency measurement" > > Date: Tuesday, 10 November, 2009, 19:29 > > > On the other hand... With GPS-aiding its argued that high performance > INS-systems are not needed. The same performance will be reached with a > low cost GPS and a mid to low performance inertial system. So I doubt we > will have low cost high performance intertial sensors anytime soon. > > -- > > Björn > >> Don't overlook that laser/fiber "ring-gyros" will drop in price the >> patents expire and the predatory pricing ends: >> >> http://www.es.northropgrumman.com/solutions/mk39/assets/mk39.pdf >> >> As much as I have enjoyed playing with Loran-C, I would far rather >> have a shoebox-sized, totally autonomous dead-reckoning backup, with >> no lightning-prone antenna, than a Loran-C receiver. >> >> Doesn't help us timing guys, but we have Cesiums if we are really >> serious. >> >> -- >> Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 >> p...@freebsd.org | TCP/IP since RFC 956 >> FreeBSD committer | BSD since 4.3-tahoe >> Never attribute to malice what can adequately be explained by >> incompetence. >> >> ___ >> 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.
Re: [time-nuts] LORAN C shutdown
In message <2455.41.130.184.218.1257890017.squir...@webmail.lysator.liu.se>, bg @lysator.liu.se writes: >High performance mechanical rotating gyros are associated with platform >systems. Ring laser gyros and fiber optic gyros are typically strapdown, >which completely dominate modern navigation. Actually, they are usually strapped down to a deliberately moving platform to avoid mode-lock-in at the mirrors, which produces a "sticky" or "discrete steps" effect at slow rates of rotation. But that is a minor detail. Poul-Henning -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ 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] 5370B PROM
Hi Joe - Thanks for the good info. I would like a back rom. Thanks, John K1AE Sent from my iPhone On Nov 10, 2009, at 4:07 PM, Joe Geller wrote: My 5370B PROM turns out to be fine (there was some operator error) I picked up a DATA I/O 201 programmer and some NOS windowed MOT MCM68764C to have some backups (this was probably overkill, since I have never actually seen a failed hp counter from ROM failure) A newly burned MCM68764C appears to work perfectly. The programmer reports SUMCHECK 7387 for U3, 5370B Ser. No. 2438A 01154 The programmer can report in the following formats: INTEL INTELLEC 8, INTEL MCS-86 HEX, MOTOROLA EXCERCIS, MOTOROLA EXORMAX, and TEKTRONIX HEX I can read these formats to a text file using a Windows terminal emulator to save them to a file, however, I do not know how to make the “ROM Image”. I was hoping to be able to say something about the ROM version, but I do not know how to compare the files I get to the available 5370B ROM image? The DATA I/O 201 does not appear to directly save the binary file. I can supply a few replacement 5370B ROMs at cost plus shipping if anyone needs one. Regards, Joe ___ 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] 5370B PROM
Good day, *** REPLY SEPARATOR *** On 10-Nov-09 at 16:07 Joe Geller wrote: >I can read these formats to a text file using a Windows terminal emulator >to save them to a file, >however, I do not know how to make the ROM Image. Technically, a ROM image is made by creating an Absolute Binary (Data I/O #16) format file of the device being read. However, formats such as you describe were, if I recall correctly, compatible with being read from a text file as long as the programmer being used to make a new device supports the format in question. I have other Data I/O programmers here which are quite capable of producing a binary image file. If you would like to send a chip to me for comparison against the source file you're curious about, I should be able to deal with it and return said chip when finished. Happy tweaking. ___ 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] 5370B PROM
At 05:29 PM 11/10/2009, Bruce Lane wrote... you describe were, if I recall correctly, compatible with being read from a text file as long as the programmer being used to make a new device supports the format in question. The common Intel Hex and Motorola S-Record formats have the advantage of being able to incorporate checksums to assure some level of integrity, which is why they're used to distribute PROM files. Both enjoy almost universal support. A binary file has no such protection. The srec utility ( http://srecord.sourceforge.net/ ) can translate between many common formats, including binary. The image Joe went out of his way to obtain turns out to be the same as the 5370B image discussed earlier on the list (and which I documented at http://www.flatsurface.com/5370A/index.html ), but there's another 4 1/2 years of 5370B date codes beyond, so there may yet be a newer version. ___ 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] LORAN C shutdown
Poul-Henning Kamp wrote: In message <2455.41.130.184.218.1257890017.squir...@webmail.lysator.liu.se>, bg @lysator.liu.se writes: High performance mechanical rotating gyros are associated with platform systems. Ring laser gyros and fiber optic gyros are typically strapdown, which completely dominate modern navigation. Actually, they are usually strapped down to a deliberately moving platform to avoid mode-lock-in at the mirrors, which produces a "sticky" or "discrete steps" effect at slow rates of rotation. But that is a minor detail. While such laser gyros need to vibrate their mirrors to avoid the locking (having heard the audioble noise out of Björns basement lab) they remain part of the strap-down system. A little bit of vibration is nothing to rotating objects. There is also gyros having no vibration at all, but uses a roll of fiber instead. 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.
[time-nuts] Loran C shutdown
Hello ! Before you throw away your Loran Receivers, have you checked what will happen with the Canadian Transmitter Chains ? Would it be possible with better antennas to receive signals from other countries ? Would be interested in hearing your input on these ideas ! Thanks ! Claude ___ 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] Loran C shutdown
Also, somebody mentioned French chains. Any info on those would be appreciated. They might worl, especially on the east coast. -John == > Hello ! > > Before you throw away your Loran Receivers, have you checked what will > happen with the Canadian Transmitter Chains ? > > Would it be possible with better antennas to receive signals from other > countries ? > > Would be interested in hearing your input on these ideas ! > > Thanks ! > > Claude ___ 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] Loran C shutdown
Is Loran C used with GPS to help make land surveying more accurate? I thought I read something about using both systems together. --- This email message is for the sole use of the intended recipient(s) and may contain confidential information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply email and destroy all copies of the original message. --- ___ 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] Loran C shutdown
Well that's what I am thinking about also. Earlier in this thread there was a mention of Europe. This would be a sky wave only signal as I recall from the navy. So I have g3plx LORAN software and will look to see what I might get here on the east coast. Suspect the Canadian chains will go very quickly since part of them uses the US chain. Or simpler then the g3plx software, just plugging in the GRI for the European chains. Have 3 austron receivers, the 2000c, 2100, and 2100f. On Tue, Nov 10, 2009 at 8:36 PM, Claude Houde wrote: > Hello ! > > Before you throw away your Loran Receivers, have you checked what will > happen with the Canadian Transmitter Chains ? > > Would it be possible with better antennas to receive signals from other > countries ? > > Would be interested in hearing your input on these ideas ! > > Thanks ! > > Claude > > ___ > 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] Loran C shutdown
The problem with the some European chains is that they have four-digit GRPs . Therefore, the standard 2000C and maybe others are useless. Regards, Antonio CT1TE Quoting paul swed : Well that's what I am thinking about also. Earlier in this thread there was a mention of Europe. This would be a sky wave only signal as I recall from the navy. So I have g3plx LORAN software and will look to see what I might get here on the east coast. Suspect the Canadian chains will go very quickly since part of them uses the US chain. Or simpler then the g3plx software, just plugging in the GRI for the European chains. Have 3 austron receivers, the 2000c, 2100, and 2100f. On Tue, Nov 10, 2009 at 8:36 PM, Claude Houde wrote: Hello ! Before you throw away your Loran Receivers, have you checked what will happen with the Canadian Transmitter Chains ? Would it be possible with better antennas to receive signals from other countries ? Would be interested in hearing your input on these ideas ! Thanks ! Claude ___ 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. - A FCUP utiliza o sistema open source de webmail Horde/IMP (www.horde.org) Visite: http://www.fc.up.pt/ http://info.fc.up.pt/ ___ 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] LORAN C shutdown
> In message > <2455.41.130.184.218.1257890017.squir...@webmail.lysator.liu.se>, bg > @lysator.liu.se writes: > >>High performance mechanical rotating gyros are associated with platform >>systems. Ring laser gyros and fiber optic gyros are typically strapdown, >>which completely dominate modern navigation. > > Actually, they are usually strapped down to a deliberately moving > platform to avoid mode-lock-in at the mirrors, which produces a > "sticky" or "discrete steps" effect at slow rates of rotation. Most RLGs have a mechanical dither mechanism, but that is only moving the optical subsystem within the gyro. There is no platform at all for the accelerometers, and the three gyros typically do not use the same dither frequency. There are RLGs (Litton/NGC Zero Lock Gyro) that have no mechanical movement, they instead have an 'optical' dithering of one mirrors. FOGs have no moving parts at all. > But that is a minor detail. True. > Poul-Henning -- Björn ___ 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.
