Re: [time-nuts] GPS Spoofing

The idea behind GPS spoofing is that one or several surface antennas and sources could be set up in such a way that they would produce believable position data that would take a vessel off course. The problem with this concept is that the person in charge of the GPS spoofing hardware has to kn

Re: [time-nuts] GPS Spoofing

Interesting comments about navigation of ships and GPS spoofing potential. As a recreational offshore captain/navigator, over the years I've used a few generations each of RDF, Loran, GPS, and radar. My most recent extended nautical travels have been on 100 passenger "exploration" ships, 300'

Re: [time-nuts] More pictures of the mystery Collins Ru

On Sun, Jul 28, 2013 at 07:54:47PM -0400, Bob Camp wrote: > Hi > > …. > > There was a suitcase Rb that was used to sync up Have Quick's on the ground. > It was a Magnavox product rather than Collins. The idea was to get the radios > netted up without *anything* going over the air. Since the rad

Re: [time-nuts] More pictures of the mystery Collins Ru

Hi …. There was a suitcase Rb that was used to sync up Have Quick's on the ground. It was a Magnavox product rather than Collins. The idea was to get the radios netted up without *anything* going over the air. Since the radios used TCXO's, sync was fairly loose. I suspect that tightened up as

Re: [time-nuts] More pictures of the mystery Collins Ru

Hi: The military UHF voice radio scrambling depends on accurate time, hence the Have Quick (and follow on programs) time transfer standard. Rb standards were used to maintain that time in the early days. The O-1814 Rb standard was used to keep time on the ground accurate so that when a plane f

Re: [time-nuts] More pictures of the mystery Collins Ru

A reference to GR and Rubidium http://www.ieee-uffc.org/frequency-control/memoria-stratemeyer.asp Did the GR 1115A, Sounds like an interesting person. On Sat, Jul 27, 2013 at 6:24 PM, Pete Lancashire wrote: > > https://plus.google.com/u/0/photos/111617808980322733757/albums/58902666012770456

Re: [time-nuts] GPS Spoofing

Hi Omega was world wide, Loran was not. Anything that operated over *long* distances (tankers, airplanes) was Omega. They pulled Omega gear off of the planes and replaced it with GPS. I suspect they did the same thing on the big tankers. Bob On Jul 28, 2013, at 6:24 PM, "J. Forster" wrote:

Re: [time-nuts] More pictures of the mystery Collins Ru

If they needed an airborne rubidium standard it must have been for digitally scrambled communications. That has been around since the 60s. Regards. Max. K 4 O DS. Email: m...@maxsmusicplace.com Transistor site http://www.funwithtransistors.net Vacuum tube site: http://www.funwithtubes.net W

Re: [time-nuts] GPS Spoofing

I'm not so convinced about this: "OMEGA was the primary means of radio navigation, world wide, from 1976 to 1997. ." There was LORAN-C, after all. And Omega was a CW, phase difference system, LORAN a pulse system. AFAIK, Omega never really made it into the uP age; LORAN certainly did. -John =

Re: [time-nuts] GPS Spoofing

The Helix coils are 25' high and have a 6' high relay: http://www.haikuvalley.com/History/OMEGA-NAVIGATION-SYSTEM/8839335_kzKJLd#!i=2042047390&k=QJbHKzM/ --marki -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob Camp Sent: Monday,

Re: [time-nuts] GPS Spoofing

No better ground plane than salt water... --marki -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob Stewart Sent: Monday, 29 July 2013 7:13 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] GPS Spo

Re: [time-nuts] GPS Spoofing

Hi Part (but not all) of that is related to handling >= 400KW pulses. A bit of it also relates to handling lightning hits on the tower. Bob On Jul 28, 2013, at 5:39 PM, "Tom Miller" wrote: > That is why they use litz wire, sometimes three inches in diameter for the > coils and for the capac

Re: [time-nuts] GPS Spoofing

That is why they use litz wire, sometimes three inches in diameter for the coils and for the capacity hat. The ground system includes miles of buried copper. Capacitors are larger than trash cans and gas filled. - Original Message - From: "Bob Camp" To: "Discussion of precise time

Re: [time-nuts] GPS Spoofing

Hi Actually not the whole story. Propagating (far field) antennas are also a function of producing the polarization you want and a good field remote from the antenna. For instance, you can get a really good field inside a toroid, but it's not a good far filed (or near field) antenna. Bob On

Re: [time-nuts] GPS Spoofing

Hi Small antennas (all antennas at 100 KHz are small) are not a matter of wavelengths of wire in the air. They are a matter of making do with what you have. Efficiency is more a matter of coil loss (or equivalent) than of antenna size. Bob On Jul 28, 2013, at 5:12 PM, Bob Stewart wrote: > S

Re: [time-nuts] GPS Spoofing

So, given the size of a typical freighter these days, what's so hard about imagining one with enough wire in the air to make that happen for whatever political or commercial reason? Bob > > From: Bob Camp >To: Discussion of precise time and frequency measure

Re: [time-nuts] GPS Spoofing

Hi So in this case we're talking about "horrible" to "even more horrible" in terms of efficiency. I'll freely grant that a 600' tower over a really good ground plane (like say the sea) is going to be way more efficient than anything I'd come up with. The same thing would apply to a matching net

Re: [time-nuts] GPS Spoofing

You can't use "efficient antenna" and "100 kHz" in the same sentence. Oh, wait... - Original Message - From: "J. Forster" To: "Discussion of precise time and frequency measurement" Sent: Sunday, July 28, 2013 3:06 PM Subject: Re: [time-nuts] GPS Spoofing The point about the duty

Re: [time-nuts] Rockwell/Conexant Jupiter(?) 10kHz Output Off Frequency

David, If you don't have any luck getting the ZOD1's to work, I have several TU30's if you need one. Please contact me off line. Regards, Doug Connected by DROID on Verizon Wireless -Original message- From: David Smith To: time-nuts@febo.com Sent: Sat, Jul 27, 2013 23:23:40 GMT+00:0

Re: [time-nuts] GPS Spoofing

Hi My antenna "design" relies mainly on a near field / far field argument. In normal antenna design, the only thing that counts is the far field. You calculate the near field mainly to get drive point impedances. In this case you are within 1/10 wavelength of the antenna. The near field energy

Re: [time-nuts] GPS Spoofing

Not so at all. What I described is a simple means to make a receiver see different GRIs and TDs than what it might see off the air. The system can accurately set any GRI in 1 uS increments and any one of several TDs to 1 uS also. That is hardly a jammer. Furthermore, if the Tek DD501s were replac

Re: [time-nuts] GPS Spoofing

I've just been catching up on this thread. The subject says GPS Spoofing, but most of the replies seem to revolve around jamming. Not the same thing. Just a thought... Rob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of J. Forster Se

Re: [time-nuts] GPS Spoofing

The point about the duty cycle being low is correct. And, there are commercial linear power amps, like the used ones made by ENI and others, that can easily put out 1 kW plus narrow pulses. Furthermore, the pulse generator is trivial to make with a Rb, 3 or more Tektronix DD501s, a simple OR gate

Re: [time-nuts] GPS Spoofing

Hi Since it's a pulse system, and you get to position your pulse for maximum effect, I don't see any reason to generate CW power. Simply mimic the lowest power slave in the chain. There's very little redundancy with Loran, so spoofing one station will mess it up. No need to mask the entire chai

Re: [time-nuts] More pictures of the mystery Collins Ru

Hi: I think (3). See: http://en.wikipedia.org/wiki/TACAMO http://en.wikipedia.org/wiki/Ground_Wave_Emergency_Network -> some converted to DGPS Have Fun, Brooke Clarke http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html Robert Atkinson wrote: Hi Tim, Three possible reason

Re: [time-nuts] GPS Spoofing

In message , Bob Camp writes: >I'm not talking about taking out Loran-C over the entire North Atlantic. >The target is a harbor sized area. For that, you certainly do not need a >600' antenna or megawatts of power. No, you need about 600W (continuous) and a loop-antenna about 5m in diameter. Do

Re: [time-nuts] GPS Spoofing

In message <581a0abf-19d8-45bb-88c3-cb351711b...@rtty.us>, Bob Camp writes: >If we are now down to a truck sized / house sized area, I'd claim that >Loran-C is dead simple to jam. That's what the truck stop gizmos are aimed at. We are not. You don't get to place your Loran-C jamming car right n

Re: [time-nuts] GPS Spoofing

Hi If we are now down to a truck sized / house sized area, I'd claim that Loran-C is dead simple to jam. That's what the truck stop gizmos are aimed at. Bob On Jul 28, 2013, at 1:09 PM, Scott McGrath wrote: > Key is GPS is EASY to deny for wide areas for both Civillian and military > users

Re: [time-nuts] GPS Spoofing

Hi I'm not talking about taking out Loran-C over the entire North Atlantic. The target is a harbor sized area. For that, you certainly do not need a 600' antenna or megawatts of power. You only need to generate a near field signal, not set up something that will propagate beyond line of sight.

Re: [time-nuts] GPS Spoofing

Key is GPS is EASY to deny for wide areas for both Civillian and military users Loran much less so and eLoran even less due to information carried by signal. And the larger the area attacked the jammer becomes easier to find due to signal strength There is no doubt that both systems can be spo

Re: [time-nuts] GPS Spoofing

In message <26bb6f2a-69ac-4587-8057-ba18a03e8...@rtty.us>, Bob Camp writes: >Bumping it a bit this way or that is not an impossibility. A little >bit of added phase this way or that is all it would take. You would have >to get the rep rate and timing right, but that's just the sort of thing a >T

Re: [time-nuts] GPS Spoofing

Hi …. and if a pulse comes up *looking* like the slave …. Loran-C wanders around enough all by it's self, with no need for help from others. Bumping it a bit this way or that is not an impossibility. A little bit of added phase this way or that is all it would take. You would have to get the

Re: [time-nuts] GPS Spoofing

Hi Except a rotating rod antenna gives you only a bearing, not a direction. At VHF and above you can use multiple antennas and directly get a bearing. Much faster and easier to automate. Bob On Jul 28, 2013, at 11:53 AM, Scott McGrath wrote: > Yes it is and it can be done with simple loop s

Re: [time-nuts] GPS Spoofing

Yes it is and it can be done with simple loop stick antennas. Prior to wide use of loran ships would use LF beacons and DF receivers either manual automatic Periodically you will see shortwave receivers with a rotating antenna and a bearing ring you would find a bearing to a couple of beacon or

Re: [time-nuts] GPS Spoofing

In message , Chris Albertson writes: >I think the GPS backups are called, None of those are usable as backups for GPS, as they use the same low-power Microwave signals as GPS. >But ALL radio navigation systems can be spoofed. The ones you can't spoof >are Loran-C. -- Poul-Henning Kamp

Re: [time-nuts] More pictures of the mystery Collins Ru

Hi Tim, Three possible reasons for needing a Rb standard, 1/ Coherent detection with a local clock 2/ Hyperbolic navigation (local reference improves the fix and holdover) 3/ Secure communications. Robert G8RPI From: Tim Shoppa To: Discussion of precise time

Re: [time-nuts] GPS Spoofing

I think the GPS backups are called, - GLONASS - Galileo - IRNSS - Compass

Re: [time-nuts] More pictures of the mystery Collins Ru

Googling a little bit, I find several references to a Collins rubidium package AFS-81 for airborne survivable VLF communications in the 60's (predating this unit by maybe two decades). Still trying to wrap my head around why that would need rubidium unless it was an airborne WWVB replacement or som

Re: [time-nuts] More pictures of the mystery Collins Ru

maybe I should read things more often .. yikes I need a vacation On Sun, Jul 28, 2013 at 7:01 AM, George Dubovsky wrote: > Well, the outside label does claim it was made by GENRAD... ;-) > > 73, > > geo - n4ua > > > On Sat, Jul 27, 2013 at 9:24 PM, Pete Lancashire >wrote: > > > > > > https://p

Re: [time-nuts] GPS Spoofing

Hi With a small jammer, you have a fast change in power vs distance. That's true regardless of frequency. The way Loran works, the "jammer" would do better if it looked like the low power slave for the area, not the highest power station. In both the case of Loran and GPS, you would need to get

Re: [time-nuts] GPS Spoofing

Hi One could say VHF is much easier to DF than LF due to the small antennas needed. Short wavelength makes the antenna for a phase based receiver easier to build. Bob On Jul 28, 2013, at 5:03 AM, stew...@g3ysx.org.uk wrote: > LF is much easier to accurately DF than VHF and above due to multi

Re: [time-nuts] More pictures of the mystery Collins Ru

Well, the outside label does claim it was made by GENRAD... ;-) 73, geo - n4ua On Sat, Jul 27, 2013 at 9:24 PM, Pete Lancashire wrote: > > https://plus.google.com/u/0/photos/111617808980322733757/albums/5890266601277045697 > > The board with the edge connector was inside the same bag the > con

Re: [time-nuts] Rockwell/Conexant Jupiter(?) 10kHz Output Off Frequency

Hi David Aside from in the Jupiter itself the Zodiac chipset was widely used in GPS navigational receivers and, just for example there's one that's possibly similar to yours, albeit marked ZOD1, shown here http://www.gpsnuts.com/mygps/gps/hardware%20reviews/randmcnally/rand_mcnally _gps

Re: [time-nuts] GPS locked 60Hz?

My mate worked in telecom in the 70's where the backup diesel generators used exactly the same method. Due to a fluke a spike or something blew all 3 globes (Australia is 3 phase). My mate assumed the generator was synced up and closed the breaker. When he picked himself up from the other side of t

Re: [time-nuts] GPS Spoofing

LF is much easier to accurately DF than VHF and above due to multipath effects. Stewart Sent from my iPad On 27 Jul 2013, at 21:44, Bob Camp wrote: > Hi > > A Loran jammer would / could work with a *much* smaller antenna if a local > area was the target. Power is easy at 100 KHz. Loran is no