Re: [time-nuts] Loran C returning to a station near you...
Speaking of which, here is a typical Loran-C item the government is selling for virtually scrap prices. There are a couple of these big-boy feedthroughs in this sale alone: http://www.govliquidation.com/auction/view?id=9831977 -Doug W6DSR -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Dale Cannon Sent: Tuesday, July 14, 2015 10:18 PM To: time-nuts@febo.com Subject: [time-nuts] Loran C returning to a station near you... Folks, I know that there is a longing for LORAN-C to return, but this weekend, I did a Google Maps flyover of each of the US LORAN-C stations (takes less than an hour). Almost all of the antennas are gone and there are no cars in the parking lots (except at Seneca which became an Army depot). This means that the equipment is probably gone, too. Or maybe this stuff will show up at auction or on E-Bay and that would solve the Austron receiver problem.. Dale Cannon, KS4FA ___ 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] KS-24361 Power Module Repair
Yes, and for those hams amongst us TN's, these switchers produce copious amounts of RFI all over the HF bands. I replaced my DC/DC converters with external linears, to stop the pollution. -Doug W6DSR This particular module had +/- 15V, and +5V on board. I have never seen so many individual switching power supplies stuffed into a single module... They were all little 5 terminal IC's, with each running at whatever frequency it felt like... -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Chuck Harris Sent: Friday, April 10, 2015 9:52 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] KS-24361 Power Module Repair That is almost a carbon copy description of how I fixed a similar module in my Ball/Efratom MGPS unit on my GPSRb unit. An oven set to 140C is your friend when doing jobs like this. The guys that make these modules are trying to make them as small as possible, so they always use tantalum capacitors, and run them very close to their ratings... in this case, it was 18V on a 20V cap. This particular module had +/- 15V, and +5V on board. I have never seen so many individual switching power supplies stuffed into a single module... They were all little 5 terminal IC's, with each running at whatever frequency it felt like... -Chuck Harris Bob Stewart wrote: This is just a brief report, not a how-to. I got a KS_24361 with a bad Lucent power module. Having nothing to lose I thought I'd see if it came apart. After unsoldering it from the motherboard, I found the usual potting compound. Fortunately, the compound was only loosely attached to the board in the brick and was easy to pick off. After that, I used a pair of needle-nose pliers to work the board out of the casing. In spite of the pic below, I first gently pried up on the corners, in succession, until the corners released. Then I worked my way toward the middle, until the board came out. Be aware that there are two small inductors on the top side of the board that have metal covers that will probably stay in the potting compound. Just leave them there. When you push it all back together the covers will go back on the inductors. http://evoria.net/AE6RV/KS/OpenUp.jpg One corner of the brick was pretty hot while I had it on, so I figured there was a shorted component. As it turned out, it was a 15uF tantalum cap with a big brown spot on it. http://evoria.net/AE6RV/KS/BadCap.jpg Here's the cap removed from the board at the upper left. http://evoria.net/AE6RV/KS/CapRemoved.jpg So, ordered the cap, put it on the board, then just pushed the pins into the motherboard for testing. I didn't even bother soldering it. http://evoria.net/AE6RV/KS/Testing.jpg Tests were good, so I stuffed the board back into the casing, and soldered it all back on the motherboard. I didn't bother repotting the bottom surface of the board. I attached the repaired KS to my good REF-0, and it's now working. Bob - AE6RV ___ 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.
[time-nuts] No GPS satellites
I'm hoping someone can shed some light on my problem receiving any GPS satellites. I have two TrueTime GPS Time Frequency Receivers, Model XL-DC. One has a regular crystal oscillator, and the other one has a rubidium oscillator. I have two outdoor GPS antennas with internal LNAs, one a 28 dB gain unit, and the other a 40 dB unit. When either antenna is connected to my Lucent KS-24361, it locks right up and tracks up to 8 satellites. When either of the antennas is connected to the XL-DCs, they just sit there and status : Looking for GPS satellites. In the Alarm menu of either XL-DC there is an alarm for Antenna. Both units say OK and if I disconnect the antenna they both logically say Open. So, what is the problem? I can't believe I don't have enough signal, after the Lucent locks-up right away. Is it possible the TrueTime sanctioned antenna has a down converter in it, perhaps placing the GPS signal from L-band to some lower frequency? I would appreciate any info the group might have... -Doug Ronald W6DSR ___ 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] Austron 1250A Tuning tool
I've had the ovens apart to replace a dead 3N128 in one of my 1250As. What you are adjusting is a trimmer cap in the oscillator circuit, and if too much pressure is applied trying to engage the slot in the trimmer, it is easy to bend the trimmer off at an angle where you will never be able to find the slot again. The Austron supplied tool is a dielectric rod of 18 cm length, 3 mm in diameter, with a 3 mm steel flat blade 2 mm in length protruding from the end of the rod. The blade easily fits into the trimmer's slot, but as was mentioned in the previous post, some of the trimmers are sticky, and require some torque to get them moving. I measured the inner oven's temperature as 63 C which is the temperature that trimmer lives at. -Doug W6DSR -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of John Reed Sent: Saturday, February 21, 2015 5:56 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Austron 1250A Tuning tool I adjusted my 1250A using a 1/8 brass rod that I got from the hardware store. I filed down the end to make it into a screwdriver. This worked fine. I could tell when the tip was engaged with the screw in the oscillator by feeling it fall into place and then I could make the adjustment. The brass didn't have any effect on the frequency. When I removed the tool the frequency didn't change. A metallic tool is needed since the adjustment screw needs some torque to make it turn. -Original Message- From: Ole Petter Ronningen Sent: Saturday, February 21, 2015 1:07 AM To: time-nuts@febo.com Subject: [time-nuts] Austron 1250A Tuning tool Hello My 1250A has drifted outside the range of the front panel control, so the coarse adjust needs some fiddling. The manual makes mention of a special tool to be used for this. I don't have the tool, the closest I can get is a 10 bamboo stick that I cunningly liberated from my wifes sushimaking mat! I wondered if anyone else on the list has this tool, and can send me a description/photo of the tip? I tried widdling the tip of my stick to various shapes, but not knowing what it is supposed to mate with, it is a bit frustrating.. Thank you all ___ 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] Austron 1250A
I own several of these units, and have for sale several more if anyone is interested. I can verify that a New Old Stock unit straight out of the box, needs to have the cover removed, and a piece of Styrofoam spacer removed from the relay you mention. It sounds like you have done that, or the seller did it. Then for many minutes with the 1250A on, and the battery switch in charge, the relay will buzz. This is perfectly normal, and is mentioned in the manual for the 1250A. By-the-way, the original battery in all the units I have powered up, never achieve the capacity to run the standard for more than a few minutes. They can be replaced with new cells, but I have also never seen any of my units with leaking cells. Hope that helps, -Doug Ronald W6DSR -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Ole Petter Ronningen Sent: Wednesday, February 18, 2015 9:47 AM To: time-nuts@febo.com Subject: [time-nuts] Austron 1250A Hello On a whim I purchased an Austron 1250A off of eBay, tested for power on only. I somehow doubt they told the whole truth there, as the unit makes a *very* noticable buzzing sound when powered on! The sound comes from a relay on the regulator board, oscillating wildly. I have a hunch that this might be because the NiCad batteries are stone dead. Has anyone experienced this relay going nuts?` Also, the manual gives clear warning not to operate the unit with the battery pack removed, but gives no reason.. Does anyone know why this might be a bad thing? Thank you! OleP ___ 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] Linear voltage regulator hints...
There exists a newer generation of linear regulators with much lower noise, designed for sensitive analog loads. Here are some representative parts. Check Analog Devices' website for other options... ADM7170/7171/7172 6.5 V, Ultra Low Noise, High PSRR, Fast Transient Response CMOS LDO Doug R. -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of ed breya Sent: Thursday, December 11, 2014 9:48 AM To: time-nuts@febo.com Subject: Re: [time-nuts] Linear voltage regulator hints... If the plan is to use a three-terminal regulator after all, I'd suggest not using a low-dropout (LDO) type if the raw input supply is noisy - the LDOs usually have PNP output transistors (for positive regulators), so may tend to have poorer HF input ripple rejection than equivalent ones with NPN passers. At low frequencies this is no problem since the regulator loop takes care of it, but as the loop rolls off, the PNP becomes a common-base amplifier, allowing more HF from the input to pass on through. I alluded to this in my previous post - from an input HF rejection perspective, it's usually best to use an NPN passer for positive supplies, and conversely a PNP for negative, working as an emitter-follower. If the raw input comes from a switching supply, there will tend to be a lot of HF ripple, so this could be a concern. If this is the case, another option is to have a two-stage regulation scheme with as much pre-regulation and filtering as possible. This of course eats into the overhead budget, so may not be practical in many situations. Ed ___ 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] Questionable question about the Lucent RFTGs
I didn't think of Selective Availability when I asked the question. Bill Clinton didn't order it turned off until May of 2000, so there is probably active software on the board to emolliate the effects. Also, yes, the 68000 latency most likely required an FPGA's real time capabilities. Thanks everyone for the answers... -Doug W6DSR -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Pete Lancashire Sent: Friday, December 05, 2014 7:29 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Questionable question about the Lucent RFTGs HPs unit cost for 68000s would have been very, very good. Add up all the instruments and laser printers (I think the controllers where parcs ?), then add the 1000's of man hours of software experience you can imagine why a 68K. On Thu, Dec 4, 2014 at 12:03 PM, Doug Ronald d...@dougronald.com wrote: I have sort of a dumb question about the Lucent KS-24361 RFTGs. Why do you suppose there is so much compute power in these units? They have the Xilinx FPGA, and the 68000 CPU just to discipline a 5 MHz oscillator? There must be more going on with these devices than meets my eyes. Thanks anyone, -Doug W6DSR ___ 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] Questionable question about the Lucent RFTGs
I have sort of a dumb question about the Lucent KS-24361 RFTGs. Why do you suppose there is so much compute power in these units? They have the Xilinx FPGA, and the 68000 CPU just to discipline a 5 MHz oscillator? There must be more going on with these devices than meets my eyes. Thanks anyone, -Doug W6DSR ___ 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] Lucent KS-24361 10 Mhz out success.
I may have missed this info in a previous post, but I am interested in tapping off the 5 MHz signal. I have my REF-1 apart, but don't have it powered. I will buffer the signal, and suspect the 5 MHz is available right around Q205, but it might be up around Q204 or Q203. Could someone advise me as to exactly where to pick off a nice 5 MHz sine wave? Thanks, -Doug R. -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of paul swed Sent: Wednesday, December 03, 2014 3:05 PM To: Time-nuts Subject: [time-nuts] Lucent KS-24361 10 Mhz out success. Have successfully tapped into the clean 10 MHz of the the Lucent and using a EL2020 50 Mhz current opamp have a very nice 10 Mhz sine wave out. Any spurs are down at least 43 db. Close in at 4Khz total span or 500 Hz/div I don't see anything down to at least 65 db. Thats the best detail the HP 8568B will allow. To get the signal out of the Lucent I sliced the 15 Mhz trace and injected the 10 Mhz into the SMA output connector. I am sure there are many other amplifiers and methods that could be used but this ones working well and can drive some real coax lengths. Now the really hard part. Mounting it and the power supply into a rack panel. 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] Lucent KS-24361, curious observation
I have also received mine, and powered them with my GPS antenna indoors. After a 20 minute wait, I had full lock, and proceeded to compare the 15 MHz to WWVB. I saw a 20 degree shift in 4 hours which was pretty linear. I don't know if that is WWVB's propagation variation, or the Lucent warming-up, but I'm a happy camper as I have never had a decent reference here before. I have not yet tapped into the diagnostic information available on the Diagnostic port. I have a couple questions which someone may have an answer for: 1) Every once-in-a-while, REF-1's NO GPS LED will flash. It flashes twice, three times, or four times, then back to extinguished for a long time. Anyone also see that on theirs, and what might the unit be trying to tell me? 2) What is the 5 MHz crystal oscillator locked to? If it the L1 or L2 carrier - cool, or the PRN code clock - okay, but if it is the 1 PPS - ugh. Since the sync signal must go through the jumper cable, I suspect it is the 1 PPS. Anyone know, and if it is the 1 PPS, is that as ugly as I believe? -Doug Ronald -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Paul Sent: Monday, December 01, 2014 8:48 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Lucent KS-24361, curious observation On Mon, Dec 1, 2014 at 11:15 AM, Graham planoph...@aei.ca wrote: It has been less than 18 hours since I powered them up so I am not yet wondering why the the REF-0 LED's are in the state they are as I have seen reports of others having to wait 24 hours or so before every locks in. There are differing states. My pair went OK+Standby in about 10 minutes but they're not stable at that point. Here's a log snippet: Log 019:20141128.00:00:00: Power on Log 020:20141128.00:00:26: Power settings ok, Int: 17 dBm, Ext: 17 dBm Log 021:20141128.00:52:21: Position hold mode started Log 022:20141128.01:28:32: GPS reference valid at 20141128.20:34:00 Log 023:20141128.20:35:04: Locked mode entered Log 024:20141129.10:35:03: Ready for 4 hour flywheel Log 025:20141129.16:35:03: Ready for 8 hour flywheel The first timestamp after power-on is 00:00 of the last valid date prior to power-off. I assume the deltas are correct. So 1:29 to Locked and 20 more hours to stable. Holdover uncertainty continues to decrease for many more hours. It decreased from hundreds of microseconds to 3 at the time of that log and is now at 900 nanoseconds. ___ 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] Lucent KS-24361, curious observation
Bob, thanks for the answers. I am guessing my Garmin active antenna isn't drawing enough current, or is on the hairy edge. I won't worry about the occasional flashing LED. My concern with the 1 PPS locking the 5 MHz oscillator isn't with the quality of the 1 PPS, but that there is only one update every 5,000,000 cycles of the oscillator. It seems like that infrequent an update would cause jitter. Maybe because the oscillator is of such high quality, it doesn't need more periodic updates. Thanks, -Doug -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob Camp Sent: Monday, December 01, 2014 3:50 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Lucent KS-24361, curious observation Importance: Low Hi On Dec 1, 2014, at 4:20 PM, Doug Ronald d...@dougronald.com wrote: I have also received mine, and powered them with my GPS antenna indoors. After a 20 minute wait, I had full lock, and proceeded to compare the 15 MHz to WWVB. I saw a 20 degree shift in 4 hours which was pretty linear. I don't know if that is WWVB's propagation variation, or the Lucent warming-up, but I'm a happy camper as I have never had a decent reference here before. I have not yet tapped into the diagnostic information available on the Diagnostic port. I have a couple questions which someone may have an answer for: 1) Every once-in-a-while, REF-1's NO GPS LED will flash. It flashes twice, three times, or four times, then back to extinguished for a long time. Anyone also see that on theirs, and what might the unit be trying to tell me? If the light flashes, that’s saying the antenna current is over / under the limit the box is looking for. 2) What is the 5 MHz crystal oscillator locked to? If it the L1 or L2 carrier - cool, or the PRN code clock - okay, but if it is the 1 PPS - ugh. Since the sync signal must go through the jumper cable, I suspect it is the 1 PPS. The 1 pps out of the GPS module is what they lock to . There is a lot of information in the archives explicating why Doppler on L1 or L2 make direct carrier lock less useful. Anyone know, and if it is the 1 PPS, is that as ugly as I believe? The PPS is s differential output. Run into a proper receiver it looks pretty good to me. Bob -Doug Ronald -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Paul Sent: Monday, December 01, 2014 8:48 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Lucent KS-24361, curious observation On Mon, Dec 1, 2014 at 11:15 AM, Graham planoph...@aei.ca wrote: It has been less than 18 hours since I powered them up so I am not yet wondering why the the REF-0 LED's are in the state they are as I have seen reports of others having to wait 24 hours or so before every locks in. There are differing states. My pair went OK+Standby in about 10 minutes but they're not stable at that point. Here's a log snippet: Log 019:20141128.00:00:00: Power on Log 020:20141128.00:00:26: Power settings ok, Int: 17 dBm, Ext: 17 dBm Log 021:20141128.00:52:21: Position hold mode started Log 022:20141128.01:28:32: GPS reference valid at 20141128.20:34:00 Log 023:20141128.20:35:04: Locked mode entered Log 024:20141129.10:35:03: Ready for 4 hour flywheel Log 025:20141129.16:35:03: Ready for 8 hour flywheel The first timestamp after power-on is 00:00 of the last valid date prior to power-off. I assume the deltas are correct. So 1:29 to Locked and 20 more hours to stable. Holdover uncertainty continues to decrease for many more hours. It decreased from hundreds of microseconds to 3 at the time of that log and is now at 900 nanoseconds. ___ 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] strange carrier
Thanks to all who responded with suggestions and comments. Here is the latest... At great effort, I moved the loop-stick antenna and preamp, now mounted on a pole, from the rear of the house to a midpoint of the house toward the front. The old position had the antenna about 10 feet off the ground. The new position now allows me to rotate the antenna, and it is 21 feet off the ground. Just my luck, that could hardly have been a worse move. Now the offending carrier is much, much stronger, and completely swamps poor little WWVB. Also, the offending illegal transmitter does not null with rotation of the loop-stick antenna as WWVB does. This to me means the generator is local to the antenna. My neighbor has a DishTV antenna and down-converter across the way from my WWVB antenna which stood a good chance of having a SMPS in it. I leaned my antenna and pole over the fence toward the dish, and the carrier immediately saturated my preamp. So, the next move is get my WWVB antenna and preamp centered on my lot, as far from illegal transmitters I can't control as possible. The analog multipliers for my Costas loop arrived today, so I'm super-anxious to get a decent signal... -Doug, W6DSR -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Doug Ronald Sent: Thursday, November 13, 2014 3:23 PM To: time-nuts@febo.com Subject: [time-nuts] strange carrier Importance: Low I'm working on my WWVB BPSK receiver and am receiving a carrier, 10 dB stronger than WWVB in Sunnyvale, California, quite stable, on the air 24/7 at a frequency of 59.99240 kHz. I have researched on Internet what it might be, with no results. I have turned off all switch mode power supplies at my location with no effect. The carrier is so stable that it seems like it must be something intentionally generated. I have not tried nulling it out with my directional antenna yet. Anyone have a clue as to what I might be receiving? Thanks, -Doug Ronald W6DSR ___ 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] strange carrier
I'm working on my WWVB BPSK receiver and am receiving a carrier, 10 dB stronger than WWVB in Sunnyvale, California, quite stable, on the air 24/7 at a frequency of 59.99240 kHz. I have researched on Internet what it might be, with no results. I have turned off all switch mode power supplies at my location with no effect. The carrier is so stable that it seems like it must be something intentionally generated. I have not tried nulling it out with my directional antenna yet. Anyone have a clue as to what I might be receiving? Thanks, -Doug Ronald W6DSR ___ 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] 5MHz ocxo
And should you decide to upgrade, I have two Austron 1250A standards, (which contain a 5 MHz OCXO), unused in original boxes, with service manual, for sale at just $500 each. The voltage control is +/- 5 VDC. I'm avoiding the fleabag site unless necessary... -Doug Ronald AE6SY -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Mark Spencer Sent: Wednesday, July 25, 2012 2:49 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] 5MHz ocxo This approach could also facilitate using a higher perfromance OCXO. This is after all time nuts (: I'm surprised to hear how few 5 Mhz OCXO's are avaliable on the bay right now. Earlier this year I picked up a nice Wenzel 5 Mhz OCXO for $100.00 --- On Wed, 7/25/12, Chuck Forsberg WA7KGX N2469R c...@omen.com wrote: From: Chuck Forsberg WA7KGX N2469R c...@omen.com Subject: Re: [time-nuts] 5MHz ocxo To: time-nuts@febo.com Received: Wednesday, July 25, 2012, 5:18 PM How about a 10 MHz OCXO and a divide by two chip? Maybe an op-amp to change and/or invert the control voltage? On 07/25/2012 02:05 PM, Paul Flinders wrote: I've finally had chance to pull my Rapco 1804M GPS conditioned oscillator apart to try to debug it. To recap I bought this a few months ago from an ebay vendor. It was fine at first (for a few hours) although I needed a better antenna or better site for the one I have but the second chance I had to spend any time on the antenna the 1804M itself decided to develop a fault running for a few seconds then restarting the firmware. It looks like the ocxo has died - pulling it from the unit and running it stand alone produces a similar result, 10MHz output for a short while, then it dies. Presumably this is related to the oven heating up and a dry joint or something else that doesn't like getting warm/expanding. The ocxo in the Rapco is an HCD-66-SC 5MHz 12V unit. They are completely sealed and I doubt I could get into it without destroying it so repair seems out of the question. There is a UK supplier of HCD Research ocxo's and although the HCD-66 is clearly obsolete, a current unit - the HCD-660 looks about the right spec (http://www.golledge.com/docs/products/ocxos/hcd660.htm). However I'm pretty certain that if I have to request a quote the price will be beyond what I can afford to spend fixing the unit. The only 5MHz ocxo available on fleabay is a Symmetricomunit but the auction has no data on it, nor can I find any on the net. It's obvious from the photos though that there are a couple of extra pins compared with the HCD-66 so it wouldn't fit the PCB. Does anyone know where I might be able to locate a suitable (used) replacement? ___ 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. -- Chuck Forsberg WA7KGX N2469R c...@omen.com www.omen.com Developer of Industrial ZMODEM(Tm) for Embedded Applications Omen Technology Inc The High Reliability Software 10255 NW Old Cornelius Pass Portland OR 97231 503-614-0430 ___ 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] Austron 1250A
I have a virgin 5 MHz secondary frequency standard to sell. Before I go the eBay route, I thought I would post it here. Contact me off-list if interested. -Doug Ronald ___ 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] Austron 1250A
I just put a new (unused - not exactly new), Austron 1250A Crystal Frequency Standard on eBay should anyone be interested. -Doug Ronald ___ 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.
