[time-nuts] Loran?
Some one gave me an old Loran receiver. It fires up, the keypad and LCD display seem to work but status is always Searching Questions: 1) I think there are still Loran transmitters? 2) What does a Loran antenna look like? A random length of wire strung up in the attic is doing nothing. -- = Chris Albertson Redondo Beach, California ___ 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?
Loran is gone from the US. Chris Albertson wrote: Some one gave me an old Loran receiver. It fires up, the keypad and LCD display seem to work but status is always Searching Questions: 1) I think there are still Loran transmitters? 2) What does a Loran antenna look like? A random length of wire strung up in the attic is doing nothing. ___ 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?
On 12/19/2010 12:46 AM, Chris Albertson wrote: Some one gave me an old Loran receiver. It fires up, the keypad and LCD display seem to work but status is always Searching Questions: 1) I think there are still Loran transmitters? 2) What does a Loran antenna look like? A random length of wire strung up in the attic is doing nothing. If you are in North America you are out of luck. You *might* pick up on European LORAN-C transmitters. So, locality first... THEN we can advice you on what antenna needs you have... and then we also needs to know what LORAN C receiver you have... 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] Loran?
A loop with preamp or an active antenna (whip with preamp). Any Loran you receive will be DX as the US chains were turned off to pay for the tax cut :-) Astrons need a external frequency standard to work does your receiver have a model/Brand ? Stanley - Original Message From: Chris Albertson albertson.ch...@gmail.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sat, December 18, 2010 5:46:58 PM Subject: [time-nuts] Loran? Some one gave me an old Loran receiver. It fires up, the keypad and LCD display seem to work but status is always Searching Questions: 1) I think there are still Loran transmitters? 2) What does a Loran antenna look like? A random length of wire strung up in the attic is doing nothing. -- = Chris Albertson Redondo Beach, California ___ 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] Frequency counter recommendation
Hi That's certainly the conclusion the TAPR guys came to. As they have found out, you need to do a run of hundreds to make it worth doing. Having a pro do it eliminates a whole lot of constraints on parts and sources. Bob On Dec 17, 2010, at 4:31 AM, David C. Partridge wrote: If your spend is in that sort of region it doesn't cost a great deal more to get a batch of boards professionally pasted, picked, placed and reflowed. Regards, David Partridge -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob Camp Sent: 16 December 2010 19:20 To: 'Discussion of precise time and frequency measurement' Subject: Re: [time-nuts] Frequency counter recommendation Hi Yes indeed, been there done that. Not very hard at all. All you need is the six layer pc board (can be bought), the FPGA (Digikey has them), a few of these and a couple of those. Spend less than $100 and you are in business if the PC board volume is high enough. In this case the next step in the business is to solder the 256 ball 1 mm spacing BGA package down on the pc board. Not so easy without the right tools... Bob ___ 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] Frequency counter recommendation
Hi If you are going to do a full boat implementation and work out all the isolation issues and packaging, the question becomes: Will it be better bang for the buck than a ~ $200 HP 5370? Bob On Dec 17, 2010, at 9:29 AM, jimlux wrote: Interesting discussion.. comments interspersed Chris Albertson wrote: Jumping ahead to design. No one wants a serial RS232 interface. they don't even make computers with RS232 ports much any more. Those guys that designed equipment that forced people to load costom USB drivers just did not think. There is no need for that. What you do is make you project appear to be some standard USB class and then the OS (Linux, Windows or Mac OSX) will already have a driver. That VNA should have presented itself as a serial port. And then the software could read from a serial port. But of course there would be not physical RS232 device. If you have to select an interface I'd rather have any wireless type. WiFi or Bluetooth. wireless interface and RF test equipment is a bad combination. If you're trying to measure small scale performance (e.g. timing at 1E-10 levels), small amounts of RF leaking in/out causes problems. This is one of the things that separates good test equipment from great equipment. It's hard to get better than 100dB isolation from packaging, and if you're looking for things at the -150dBm level, something at 0dBm is huge. But if you are building a modular system you do NOT want to pick one. You just make a project standard to use (say) I2C, SPI, two wire ir whatever. Then the counter module is controlled by i2c and if you want to connect it to a computer you build the USB module but if you want a stand alone no-computer instrument you build the front panel that has LED numbers. That is the entire ont is modular, you avoid this kinds of decisions and allow for easy upgrade as technology changes. IR/fiber optic interfaces are very intriguing. Too bad that the plastic fiber stuff costs more than conventional wires/connectors. Other questions to resolve are how many slices to cut the pie into. I would argue for very small single funtions bulding blocks so we don't have the HPSDR problem of years of time to design each one. Against that: every connection causes potential troubles. A better solution for the generalized case is to put multiple functions together, but don't necessarily connect them all. Think of the old IF strip chips. Oscillator, amplifiers, variable gain stages, detectors, all on the same chip but the ins and outs brought out to pins. I don't think you want to bring them out to connectors, but, rather, provide a way to do interconnections, etc. Selecting a physical chassis to use willl take time. I like the idea of using a disk enclosure because then you can buy a 1U or 8U rack or an old PC chassis, If you modual looks like a disk there are plenty of things it can fit into. old pc chassis is a very limited life item in a particular configuration. do you mean my old IBM PC? Or an AT? or a tower case? or a midsize case? When you say disk drive size, do you mean 5 1/4 floppy/CD-ROM/DVD or something else. Packaging is going to be critical for high performance. Look at boxes from COMPAC, for instance. From my experience, for something like this to take off one person has to take ownership of the project and run with it, make the web site, write some golas and build something that works. Only then do other jump in and help. It really would be good to have a Time and Frequency Instrumentation Project as currently the state of the art seem to be that you simply buy something from a Chinese eBay reseller. This is hardly what I'd cal innovation. ___ 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] Frequency counter recommendation
Bob Camp wrote: Hi If you are going to do a full boat implementation and work out all the isolation issues and packaging, the question becomes: Will it be better bang for the buck than a ~ $200 HP 5370? Isn't that the classic New vs Used discussion, though? Those 5370s won't be available for $200 all the time The used equipment dealers charge more like $750-2k for that, depending if it's an A or a B, or if it's calibrated, etc. The lowest price on eBay is around $700 ___ 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] Frequency counter recommendation
Hi In the case of a $200 5370, you have to wait a while to find one. When you get it, you likely have to do some work to get it running. At the very least you will need to do a cal. My guess is that a counter project would be very similar. There is an order and build process that happens every so often. Eventually you get a set of boards that *might* work. They still need a bit of this and that to get them running. Once running you need to do a cal. The calibrated and running counter is something you can have tomorrow (more or less). That's very different than the kit of boards. Bob On Dec 18, 2010, at 11:07 PM, jimlux wrote: Bob Camp wrote: Hi If you are going to do a full boat implementation and work out all the isolation issues and packaging, the question becomes: Will it be better bang for the buck than a ~ $200 HP 5370? Isn't that the classic New vs Used discussion, though? Those 5370s won't be available for $200 all the time The used equipment dealers charge more like $750-2k for that, depending if it's an A or a B, or if it's calibrated, etc. The lowest price on eBay is around $700 ___ 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] Frequency counter recommendation
Bob Camp wrote: Hi In the case of a $200 5370, you have to wait a while to find one. When you get it, you likely have to do some work to get it running. At the very least you will need to do a cal. My guess is that a counter project would be very similar. There is an order and build process that happens every so often. Eventually you get a set of boards that *might* work. They still need a bit of this and that to get them running. Once running you need to do a cal. The calibrated and running counter is something you can have tomorrow (more or less). That's very different than the kit of boards. Bob But, looking at the $750 price point, you should be able to do better on the boards and not needing to fiddle. More turn-key. The TAPR VNA is in that price range, and was basically plug it in in, and it works. ___ 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] Frequency counter recommendation
It all depends on the goal. Is it to have a working instrument or to learn how they work and maybe to push the state of the art ahead a little One might ask the same question about ham radio: Why bother with all that work? If you want to talk to some one just buy a cell phone and be done with it. Yes if that was the goal the cell phone is the obvious solution. I think there are ony two reasons to build vs. buy. (1) You want to make something that you can't buy, or (2) you want to learn about the technology. One feature I'd add if I were building this is a self-calibration with GPS. There are a lot of features I can think of. I'd like a web server built-in so the instrument would be operated from an iPhone The calibrated and running counter is something you can have tomorrow (more or less). That's very different than the kit of boards. -- = Chris Albertson Redondo Beach, California ___ 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?
This is a marine navigation unit sold under West Marine's own brand name.It looks modern and automated. Has functions on it like anchor drift alarm Where you fix your location then set a radius and if the unit moves outside the radius it beeps loudly. Just what you'd want if your ship of dragging anchor. The unit is very small and modern looking. It is controlled with a keypad and large LCD screen. Zero analog knobs. My guess is that this thing wants an active whip antenna of some kind. There is an BNC on the back. I don't think this is worth a lot of time, not if the transmitters are gone. I thought I read they were going to continue for another 20 years. On Sat, Dec 18, 2010 at 4:01 PM, Magnus Danielson mag...@rubidium.dyndns.org wrote: On 12/19/2010 12:46 AM, Chris Albertson wrote: Some one gave me an old Loran receiver. It fires up, the keypad and LCD display seem to work but status is always Searching Questions: 1) I think there are still Loran transmitters? 2) What does a Loran antenna look like? A random length of wire strung up in the attic is doing nothing. If you are in North America you are out of luck. You *might* pick up on European LORAN-C transmitters. So, locality first... THEN we can advice you on what antenna needs you have... and then we also needs to know what LORAN C receiver you have... 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. -- = Chris Albertson Redondo Beach, California ___ 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] Frequency counter recommendation
Hi The real thing you would learn about is writing code that runs an FPGA. The other gotcha here is that the feature list can get pretty large: 1) WiFi interface 2) Bluetooth interface 3) USB 2.0 interface 4) RS-232 interface 5) HPIB emulation of an HP box 6)Ethernet interface - combined with - 1) Web server software 2) Windows PC application / logging software 3) Mac application / logging software 4) Linux application / logging software 5) iPhone application software 6) iPad application software - combined with 1) Front pannel controls 2) Front pannel display 3) Front interface connections (DUT's) 4) Rear pannel standard interfaces and controls combined with 1) Internal hard disk storage 2) Flash card storage 3) USB stick storage 4) SD card storage 5) Battery backed RAM storage combined with 1) Some number of counter inputs 2) Some number of reference inputs 3) Internal GPS receiver 4) Internal Rb standard - combined with --- 1) Battery power 2) Auto 12 V power 3) AC line power So lest's see, that's 3 x 4 x 5 x 4 x 6 x 6 = 8,640 combinations. That does not include any options that actually relate to how the gizmo works. That's just talking about the eye candy around the thing. A practical device might be: 2 DUT inputs 10 MHz reference input RS-232 to connect to a USB dongle +12 DC power Application software TBD. Bob On Dec 18, 2010, at 11:29 PM, Chris Albertson wrote: It all depends on the goal. Is it to have a working instrument or to learn how they work and maybe to push the state of the art ahead a little One might ask the same question about ham radio: Why bother with all that work? If you want to talk to some one just buy a cell phone and be done with it. Yes if that was the goal the cell phone is the obvious solution. I think there are ony two reasons to build vs. buy. (1) You want to make something that you can't buy, or (2) you want to learn about the technology. One feature I'd add if I were building this is a self-calibration with GPS. There are a lot of features I can think of. I'd like a web server built-in so the instrument would be operated from an iPhone The calibrated and running counter is something you can have tomorrow (more or less). That's very different than the kit of boards. -- = Chris Albertson Redondo Beach, California ___ 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?
There never was a Loran receiver with a keypad. I am certain he meant Loran C. Loran is (was) the common name for the service... But then, you already knew that, and were just trying to stir things up. -Chuck Harris Max Robinson wrote: He didn't say Loran C he said Loran. That is the old system that used to operate just above the AM broadcast band and took away most of the 160 meter ham band. That hasn't been around for decades. I don't think there is a version of it operating anywhere in the world. ___ 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] Frequency counter recommendation
For me, at least, the purpose is twofold, to learn, and to get a better instrument. The idea of being able to discriminate between two inputs a few ps apart is fascinating and something I'd like to learn how it is done. The VNA is a good comparison. I have a nice scalar nw but would like a VNA. So I built one of the n2pk VNAs. Great experience, great instrument. And I know a lot more than I did before. I think this project could be done sans prescaler, e.g. good to at least a hundred MHz, two inputs, 10mhz timebase input, rs232 out ( with ftdi USB option for a couple of hundred dollars in kit form. Would that be great for everyone? No. But would at least 10 people buy one and/or participate in the project? Probably. Could a design be done that could support all those options someone specified? Probably. Would one person be willing to design them all? No way. Would all that stuff be less than a 5370? No way. Would I want one of these and a 5370? Probably. But that what makes us nuts, isn't it? The other Bob On Dec 18, 2010, at 9:39 PM, Bob Camp li...@rtty.us wrote: Hi If you are going to do a full boat implementation and work out all the isolation issues and packaging, the question becomes: Will it be better bang for the buck than a ~ $200 HP 5370? Bob On Dec 17, 2010, at 9:29 AM, jimlux wrote: Interesting discussion.. comments interspersed Chris Albertson wrote: Jumping ahead to design. No one wants a serial RS232 interface. they don't even make computers with RS232 ports much any more. Those guys that designed equipment that forced people to load costom USB drivers just did not think. There is no need for that. What you do is make you project appear to be some standard USB class and then the OS (Linux, Windows or Mac OSX) will already have a driver. That VNA should have presented itself as a serial port. And then the software could read from a serial port. But of course there would be not physical RS232 device. If you have to select an interface I'd rather have any wireless type. WiFi or Bluetooth. wireless interface and RF test equipment is a bad combination. If you're trying to measure small scale performance (e.g. timing at 1E-10 levels), small amounts of RF leaking in/out causes problems. This is one of the things that separates good test equipment from great equipment. It's hard to get better than 100dB isolation from packaging, and if you're looking for things at the -150dBm level, something at 0dBm is huge. But if you are building a modular system you do NOT want to pick one. You just make a project standard to use (say) I2C, SPI, two wire ir whatever. Then the counter module is controlled by i2c and if you want to connect it to a computer you build the USB module but if you want a stand alone no-computer instrument you build the front panel that has LED numbers. That is the entire ont is modular, you avoid this kinds of decisions and allow for easy upgrade as technology changes. IR/fiber optic interfaces are very intriguing. Too bad that the plastic fiber stuff costs more than conventional wires/connectors. Other questions to resolve are how many slices to cut the pie into. I would argue for very small single funtions bulding blocks so we don't have the HPSDR problem of years of time to design each one. Against that: every connection causes potential troubles. A better solution for the generalized case is to put multiple functions together, but don't necessarily connect them all. Think of the old IF strip chips. Oscillator, amplifiers, variable gain stages, detectors, all on the same chip but the ins and outs brought out to pins. I don't think you want to bring them out to connectors, but, rather, provide a way to do interconnections, etc. Selecting a physical chassis to use willl take time. I like the idea of using a disk enclosure because then you can buy a 1U or 8U rack or an old PC chassis, If you modual looks like a disk there are plenty of things it can fit into. old pc chassis is a very limited life item in a particular configuration. do you mean my old IBM PC? Or an AT? or a tower case? or a midsize case? When you say disk drive size, do you mean 5 1/4 floppy/CD-ROM/DVD or something else. Packaging is going to be critical for high performance. Look at boxes from COMPAC, for instance. From my experience, for something like this to take off one person has to take ownership of the project and run with it, make the web site, write some golas and build something that works. Only then do other jump in and help. It really would be good to have a Time and Frequency Instrumentation Project as currently the state of the art seem to be that you simply buy something from a Chinese eBay reseller. This is hardly what I'd cal innovation. ___ time-nuts mailing list -- time-nuts@febo.com To
