Re: [time-nuts] Looking for a low power very low noise DC/DC converter (100 - 200 ma 10VDC or 15VDC)
On 10/30/16 22:17, Poul-Henning Kamp wrote: > > In message <b9fda620-e1da-1f84-4109-1757951d2...@woods.net>, Christopher > Brown writes: > >> Could not find anything with really good specs so am currently thinking >> something like a Traco TDN 3-1213WI (200ma 15V) feeding a filter into a >> low noise linear reg to -10VDC followed by another filter. > > Look at their TVN 5WI instead ? Hmm, twice the price but 80% less ripple, think I will try one. > > If you want _really_ low noise the TYL/TVL is there, but have restricted > input-range. Yes but only have ~ 13.6 to start, hate to linear it to 5 then step back to 9. Thinking filter/caps > TVN 5-2413WI > filter/caps > Fairchild LM7910CT With a 10uf tant on LM output, say 2ohm metal film then > 100uf oscon type. Likely in a small metal box with feedthrough caps. It it were not for the fact that three different subsystems depend on the -9 as a <0 pulldown (and they all tie together at some point) I would just switch the APC/ALC opamps to split-rail and switch from pulling Q4 G1 negative to pulling Q4 G2 from ~ 4V to 0. ___ 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] Looking for a low power very low noise DC/DC converter (100 - 200 ma 10VDC or 15VDC)
Not entirely on subject since this is for a transceiver, but figured this would be the group most likely to generate a useful answer. I happen to like the older Icom IC-271H and 471H, I have a pair of each where one is currently the control and one is the in-progress unit. All the normal stuff has been done, complete teardown and cleaning, all cold joints, broken traces and iffy stuff dealt with, all new electrolytics, etc. On through basic improvments like replacing the final output jumper from the filter to the rear SO239 with a RG400 jumper into a crimp type N bulkhead to reduce RF in the chassis. And of course a very careful alignment. Have been going through everything step by step replacing fets with newer lower NF units, caps and resistors in critical sections with lower TC ones. Anyway, while cleaning up the "APC/ALC" circuit to eliminate overshoot I found a great deal of noise that caused issues as the APC circuit was made faster to eliminate overshoot. Tracked it all down to the -9 supply (nominal, actual -10VDC), a very old metal can DC to DC that happens to be physically located on the CSS board but as its own seperate circuit. It feeds -10VDC to radio and that is used in both the TX APC/ALC to vary gain of the first amp (3SK74) after the SSB filter or FM modulator (as the pulldown voltage). It also feeds into several op-amps in the AGC and APC circuit. It was down < -45dbm (at xcvr output) but the APC is always running at least slightly negative causing a multi-mhz wide noise increase. In FM, it also AM modulates the carrier at 10 - 15 Khz. All well under legal limits (90 - 100db below transmitter output) but it just bothers be and any attempt to make the APC circuit more sensitive makes it worse. So first step was attacking the switcher circuit. Replaced the 100uf 16V Al caps with Panasonic OsCon types, 25V 150uf paralleled with .1uf ceramics. This took care of the wideband RF and fixed the multi-mhz wide hump, but the 10 - 15 Khz (depends on load) AM mod when in FM got better by ~ 10db but is still there at around -50dbm. I am looking at disconnecting the entire circuit on the CSS board and replacing with a modern DC/DC w/ filters on a seperate board. Initial though was a very low noise isolated output 10V DC/DC converter that could be rigged as a -10V supply. Could not find anything with really good specs so am currently thinking something like a Traco TDN 3-1213WI (200ma 15V) feeding a filter into a low noise linear reg to -10VDC followed by another filter. I was hoping someone here might have a better suggestion as to method or DC/DC converter. "Long" term stability (seconds and longer) is not really an issue, it could wander by a few hundred mv and not be an issue, but any noise is as it will end up coupled into the transmit chain and AM modulate things...At lower frequencies the circuits in question actually have a fair bit of gain too. Just to get a little closer to on-topic, the radio in question actually has crystal heaters on all XOs and my biggest issue onb that front is a repeating ~ 4.5Hz jump on a ~ 10.24 Osc that pulls the VCO by ~ 60Hz for minutes to hours before reverting. ___ 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/Z3812A GPSDO initial setup
Ahh, I read adjust the regulated float power supply to 28 volts as including the protection diode as part of the PS and 28VDC straight to batteries. Have a half built setup like this on the bench right now. 36VDC unreg supply feeding 2 LM317 regulators with 5amp diodes on output. Once floats a series pair of small 12v gelcells at 27.2 and the other a single at 13.6 Need to get the enclosure and the AC filters done, they will be 24/7 powering 10811B type OCXO I want to setup as a standalone ref. On 10/25/14, 5:54 PM, Tom Miller wrote: I really don't disagree with you. I did say run the supply at 28.0 and use a diode off the supply to the battery. That would place the float voltage at 27.3 or so. Best would be to follow the manufacturers float service recommendations. Ideally it should also be temperature compensated with a -2.4 mV/°C slope. Not a problem with how we use these in the lab though. And yes to get the longest run time, just power the main unit from the battery as Bob suggested. Now I am just waiting on some DB-9 connectors. I ran out of them and the local RatShak went TU. Tom - Original Message - From: Christopher Brown cbr...@woods.net To: time-nuts@febo.com Sent: Saturday, October 25, 2014 5:32 PM Subject: Re: [time-nuts] Lucent KS-24361/Z3812A GPSDO initial setup Might want to dial that back a bit. Since 12V/7ah batteries are mentioned I am assuming standard small gelcell units. Proper float voltage for a deep cycle is lower than a SLI type, and gellcell even lower. Generally 13.6 - 13.8 would be the gellcell range, with 13.6 being right on for long life use of _small_ batteries. Equalizing charge wold be 14 - 14.2. Floating a small gelcell at 13.6 (27.2) v.s. 14 can mean the diff between 12 - 24 months v.s. 5 - 7 years service life. On 10/25/14, 11:39 AM, Tom Miller wrote: These units are ideal for powering via a float charged lead acid battery. Use two 12 volt / 7 AH batteries in series and adjust the regulated float power supply to 28.0 volts. Be sure to use a diode from the supply to the battery just in case the supply can't be back fed during a power fail. Tom - Original Message - From: Bob Camp kb...@n1k.org To: Bob Stewart b...@evoria.net Cc: Time Nuts time-nuts@febo.com Sent: Saturday, October 25, 2014 3:01 PM Subject: Re: [time-nuts] Lucent KS-24361/Z3812A GPSDO initial setup Hi Spend the effort, get an antenna outside the house. Beg / borrow / steal a UPS. Even a brand new one is less than you paid for the 3812. 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. ___ 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/Z3812A GPSDO initial setup
Might want to dial that back a bit. Since 12V/7ah batteries are mentioned I am assuming standard small gelcell units. Proper float voltage for a deep cycle is lower than a SLI type, and gellcell even lower. Generally 13.6 - 13.8 would be the gellcell range, with 13.6 being right on for long life use of _small_ batteries. Equalizing charge wold be 14 - 14.2. Floating a small gelcell at 13.6 (27.2) v.s. 14 can mean the diff between 12 - 24 months v.s. 5 - 7 years service life. On 10/25/14, 11:39 AM, Tom Miller wrote: These units are ideal for powering via a float charged lead acid battery. Use two 12 volt / 7 AH batteries in series and adjust the regulated float power supply to 28.0 volts. Be sure to use a diode from the supply to the battery just in case the supply can't be back fed during a power fail. Tom - Original Message - From: Bob Camp kb...@n1k.org To: Bob Stewart b...@evoria.net Cc: Time Nuts time-nuts@febo.com Sent: Saturday, October 25, 2014 3:01 PM Subject: Re: [time-nuts] Lucent KS-24361/Z3812A GPSDO initial setup Hi Spend the effort, get an antenna outside the house. Beg / borrow / steal a UPS. Even a brand new one is less than you paid for the 3812. 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] HP5370 extender cards?
YES! Currently working my way through 3 salvaged 5370Bs. :) On 8/13/14, 12:43 PM, Mark Sims wrote: Well, after doing my TM500 extender cables, I was thinking of doing an extender board for the HP5370 boards. It would take two 36 pin extender cards to extend a card out of the card cage (the count chain board has a different connector spacing than the other boards so splitting the extender onto two boards lets one be able to extend the count chain board also). The board at the front of the unit has a different pin-count connector than the other boards and may not warrant doing its own extender card. Is there any interest out there in HP5370 extender cards? Depending upon quantity, cost should be in the $15 to $20 range. ___ 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] Speaking of 5370s
If they were it would be a non issue, know how to do the basic fixes for those and have multiple donors. The bad switches on my 5370B are the slide switches on the right, start sep/com, atten, etc. This unit went through a warehouse style surplus dealer and took impact damage, nothing major to the unit but enough impact in the projecting lever to damage the internals. Switches only switch intermittently, or make intermittent contact, or are open unless pressing a finger on it... On 8/31/13 3:53 PM, Pete Lancashire wrote: If the switches your talking about are the push buttons or Bill West switches http://www.rbarrios.com/projects/HPSWITCH/ if now .. sorry -pete On Fri, Aug 30, 2013 at 2:32 AM, Christopher Brown cbr...@woods.net wrote: Working on reviving a 5370B, have everything working except the switches. (multiple switches took impact damage). So, if anyone has 5370 or 5345 front switch/control board(s) they want to part with, let me know. ___ 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] Speaking of 5370s
I have 4 5335s, one very nice unit repaired by KN5U, two I repaired myself and one I am still working one. (2 std, 2 option 40) The 5334 and 5335 to not use the same style switches as the 5370. HP liked to re-use parts, except where they did not. This gear comes from a time when alot more parts were limited selection or even custom production, re-use of specific high-quality parts across more than a decade of production and multiple models was alot more common. The 5370 and 5345 are from around the same time, and to my eye it seems obvious that the same team was involved in the design, the channel switch layout is almost identical and appears to use the same switches for the same purposed except the start/common switch that is a three way in the 5345. But, one 3 out of 7 of that style switch are damaged on my 5370B, and 6 of the 7 on a 5345 appear to be exactly the same. On 8/30/13 3:03 AM, Bob Camp wrote: Hi Don't know if the switches are compatible, but the 5334 and 5335 are a lot more common than the 5345 and 5370. For that matter I'd bet there are a bunch of same era DVM's and such that have switches that might work. Bob On Aug 30, 2013, at 2:32 AM, Christopher Brown cbr...@woods.net wrote: Working on reviving a 5370B, have everything working except the switches. (multiple switches took impact damage). So, if anyone has 5370 or 5345 front switch/control board(s) they want to part with, let me know. ___ 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] Speaking of 5370s
Working on reviving a 5370B, have everything working except the switches. (multiple switches took impact damage). So, if anyone has 5370 or 5345 front switch/control board(s) they want to part with, let me know. ___ 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] Remote GPS Oscillator Steering
I happen to have a less than ideal ham shack/lab and antenna setup. The shack/lab is second floor in the rear. The main antenna is an inverted L 30ft straight back from the shack. There are about 50 pounds of type 31 ferrite in the house suppressing _everything_ to the point that I cannot tell whether house power is on or off on any band. If I swap out a single 4ft jumper in my 10Mhz dist system with generic rg58 it is easily detectable. Not strong enough to swamp wwv during peak hours, but as strong or stronger about 12 hours of the day. I got tired of wasting time tracking down issues. Times Microwave LMR-240 is ideal for 10Mhz dist and very well shielded. All my timing/small signal stuff is LMR-240. All of the antenna runs and large signal stuff is LMR-400 or LMR400-UF. When I originally temped up my 10Mhz dist system (tbolt feeding 5087 feeding 10 HP devices) using rg58 I had on hand... The 11 runs (about 70 feet total) radiated enough match or exceed wwv receive strength 24/7 Now, 500 feet away, diff story but it does not take much leakage with 30ft seperation. With LMR-240... I have to use a pickup antenna in the middle of my lab to detect 10Mhz leakage and only then when the band is closed and background noise at a minimum. Even good RG58 is 78% shield coverage or less, with odd/generic stuff with 50% coverage floating around. 240 is multi-layer 100% coverage...rated at 90db shielding. On 4/18/13 8:23 AM, Hal Murray wrote: i...@g7iii.net said: Oh I know it can handle it, I was trying to avoid a nice 10MHz signal on an unshielded conductor smack on the Amateur Radio 30m band :) It's more RF here than Time/Frequency, and if I can avoid clashes, so much the better... Has anybody measured the radiation from various types of coax and/or twisted pairs? It would be interesting to see how they compare and/or how they compare to things like unterminated unused outputs or emissions from gear with the lid off and things like that. ___ 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] Connectors
If using silicone oil or grease you do need to keep the water glass issue in mind. If exposed to chlorine or phosphorus in can convert to straight silicon leaving a glass coating. Silicon oil containing contact cleaners used in a marine environment can be an issue. phosphor-bronze alloy contacts as well. Electrical arcing will do it too. A dry connector without phosphorus containing alloys and solid contact (no arcing) is ok though. Personally I use the 3m self fusing silicone tape with 3M 88 overwrap on just about anything outside. On 4/12/13 10:21 AM, Brooke Clarke wrote: Hi: Water has a dielectric constant around 60 compared to plastic that just over 2. So if water gets into the connection there's going to be problems. It turns out that Silicon grease has a dielectric constant very close to plastic so filling an open RF connector with Silicon grease prior to mating them is a great way to water proof the joint. See Weatherproofing at http://www.prc68.com/I/OE254.shtml Have Fun, Brooke Clarke http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html brent evers wrote: BTW - 3M Scotch rubber tape is regularly used in the offshore industry to make waterproof connections to 6000m/10,000psi. I use it on any/all outdoor signal (RF/Microwve antenna connectors, amphenol, etc) connectors as well. I cover the rubber tape with a layer of electrical tape (Super 88), and then a layer of scotchguard over that. Scotch rubber tape comes in both a linered (23), and liner-less (130C) version. I far prefer the liner-less 130c. To make sure this is time related, my two Thunderbolt antenna connectors are also sealed this way. Brent On Fri, Apr 12, 2013 at 11:16 AM, Rob Kimberley robkimber...@btinternet.com wrote: It's a very useful material, also called Self Amalgamating Tape. Been using it for years for all sorts of outside cable work. Rob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Azelio Boriani Sent: 12 April 2013 14:00 To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Connectors Sorry, not neoprene but self-sealing polyisobutyl tape, very effective for the outdoor antenna work**. I have recently opened a sealed connection, after 10 years, and the protected connector appears as new. On Fri, Apr 12, 2013 at 2:38 PM, Azelio Boriani azelio.bori...@screen.itwrote: I use neoprene tape to make really water tight connections for all type of connectors. On Fri, Apr 12, 2013 at 1:27 PM, Bob Camp li...@rtty.us wrote: Hi The fancy F connectors are indeed waterproof if: 1) You have the right cable 2) The cable and connector match up 3) The tool and the connector match up The auction sites are a great place to get samples of connectors and tools that apparently work with no known cable . If you are not careful about the trim on the dielectric / positioning , they can have issues above 1 or 2 GHz. Even a lot of care they don't really do the job above 5 GHz. Exactly where they drop out depends (of course) on your return loss expectations. Bob On Apr 11, 2013, at 4:21 PM, Gordon Batey gpba...@wildblue.net wrote: Greetings, I have used the longitudinal compression F connectors for some time now with several GPS units and RG-6 cable. They certainly appear to be waterproof and quite sturdy. Not inexpensive but very serviceable. I found a kit with the installation tool and connectors and separate connectors at LOWES that does a nice job. I also found one for BNC that use the same principle but have not used it yet. Gordon WA4FJC ___ 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. ___ 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] Possibly off topic - Jitter on Ethernet over poweradapters
Ahem! Ethernet over powerline! NOT PoE! The various forms of ether over power are (for practical purposes) a wireless ethernet protocol coupled into the AC wiring. And yes, it is noisy timing wise, for all the same reason that a simplex/shared variable rate 802.11 system is. On 2/10/13 9:15 PM, David J Taylor wrote: It is unlikely to add much noise. The PoE device only puts a DC bias on the twisted pair. The data signal is differential. It is transformer couple to is pretty much is immune to common mode noise. So even iif the DC bias was noisy I don't thing it would matter. Chris Albertson Redondo Beach, California Chris, This isn't PoE we're discussing. It's data over mains wiring. 110 V AC to you, 240 V AC to me. Homeplug. http://www.dabs.com/products/zyxel-pla4201-500mbps-mini-powerline-ethernet-adaptor-twin-pack-83VC.html?q=ethernet%20power%20linesrc=16 Cheers, David ___ 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] WWVB new modulation...
Ahh. Small lot w/ antenna restrictions here, so my main antenna is a inverted L 35ft from my second floor shack. Means that any leakage that can be detected in the shack with a small loop at 4 feet can be easily heard on the main antenna. So, filters and ferrite chokes on everything, LMR240, 400 or 400UF for everything except a few temp use jumper, and I clear all the seems of all the gear, check for leaks and even keep a few rolls of conductive adhesive copper EMI tape around. Like the be able to run all my gear without hearing it, and figure any egress is a potential egress. If the antenna 35ft away can hear it, then 500w transmit on the same antenna is likely to get in and screw with the gear. Chris - WL7CLA On 11/24/12 7:24 AM, Burt I. Weiner wrote: Hi Chris, I'm sure they're leaking pretty badly, but it's not enough to bother my normal usage. My other receivers do not hear my standards even though they are in the same rack, but the Heathkit does, even with an outside antenna. The Heathkit's front end is not shielded worth beans as it was not intended to operate in this kind of environment. My two DATUM 9390's feed two video D.A.'s Video Patch bays and all my cables are Belden 8281. The D.A.'s are rack mount and use plug in cards and are not that well enclosed. Burt, K6OQK From: Christopher Brown cbr...@woods.net To: time-nuts@febo.com Subject: Re: [time-nuts] WWVB new modulation... On 11/23/12 8:28 AM, Burt I. Weiner wrote: I still have two of the Heathkit clocks, but alas, they won't work at home because of my standards. Burt, K6OQK Are your equipment and interconnects leaking that badly? Burt I. Weiner Associates Broadcast Technical Services Glendale, California U.S.A. b...@att.net www.biwa.cc K6OQK ___ 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] WWVB new modulation...
On 11/23/12 8:28 AM, Burt I. Weiner wrote: I still have two of the Heathkit clocks, but alas, they won't work at home because of my standards. Burt, K6OQK Are your equipment and interconnects leaking that badly? ___ 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] Is it sensible to update every few seconds from NTP server?
There are 2 different things here. Setting the time based on a single query. Disciplining the local clock Many of the built in NTP clients just Set the time every X Setting one of these to SET the local clock every X seconds is a less than good thing. If you timing needs are loose, let the client _set_ the time once an hour or day. If you need tight timing, install a full NTP setup. Normally this means... Host starts up Host performs a _set_ to get the time within a few tens of ms Host then fires up a proper ntp server, with a list of remote service. This talks to all of the provided servers, figures the local osc offset, compensates and keeps everything in-line. This is a much better (and more stable) setup than hard setting the clock every 4 seconds On 11/7/12 12:41 PM, David Kirkby wrote: Someone at my radio club uses some mode of operation where accurate time is required. He said the standard Windoze clock does not keep sufficiently accurate, so he has software which updates from an NTP server every 4 seconds or so. It's not exactly a denial of service (DOS) attack, but seems almost close to it in NTP terms to me. I can't really believe updating every few seconds is sensible myself, but he assures me it works very well. (I'm rather hoping it does not use a stratum 1 server!) I'm sure someone will say if you want accurate time on a PC, to use some combination of GPS, rubidium or OCXO with a 1 pps pulse and a serial port on a FreeBSD or similar computer. But that's probably not practical if your software only works on Windoze. Any comments? Dave, G8WRB. ___ 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] Tracking NTP displacement and correlationbetweentwo clients.
That is his point. Initial time comes from MB clock. System (OS) time is set from that at boot. During NTP startup for a client it is normal to do a ntpdate to hard set the OS clock (direct one time set). From there ntpd would track and adjust. HOWEVER, there are limits to how much ntpd will skew the clock to keep it in sync. If the OS clock is drifting faster than this amount ntpd will not be able to adjust it fast enough. Think bad hardware or buggy BIOS, OS clock ends up running too fast or too slow for ntpd to compensate for. On 10/5/12 12:46 AM, David J Taylor wrote: David, The problem is that they start in sync and over the course of a day drift that far apart despite having NTP running. We're not sure why NTP isn't correcting it along the way. Though at this point, we are looking at a firmware bug. Thanks! Bob === Bob, I take it that you are booting the PC at the start of the day, and it syncs to NTP servers at that time? If the internal clock is off (when undisciplined) by more than 500 ppm (43 seconds/day) NTP will not control it. I suggest measuring the clock error when it is not being controlled by NTP, and then we can progress. (Or you find the firmware problem). Cheers, David ___ 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] Symmetricom 58532A and 58536A group delay figures
Assuming it does not snow again, should finish the cabling to the new rooftop tripod and switch to the new antenna and splitter tomorrow. For the LMR400 main run and jumpers is simple enough, will just measure. That leaves the antenna and splitter, both have and amp and bandpass filter and I am assuming a combined delay that is likely greater than the cable delay given the short runs. Nothing is listed in the datasheets, but they are the semi-marketing sheets (only a couple pages) rather than a proper datasheet. Anyone know what the delay for this amp and splitter is? Or better yet a delay v.s. temp plot? Thanks ___ 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] Modern motherboard with RS232 port
I stand corrected, shows what I get for listening to a UPS vendors documentation. On 8/19/12 11:52 AM, Tom Miller wrote: No it is not. VA * PF = W for VA = volt amps, PF = power factor, W = watts (or true power) PF = the cos of the phase angle between the current and the voltage (assuming both are sine waves) + Peak Volts * 0.707 = RMS volts, again for sine waves only. + - Original Message - From: Christopher Brown cbr...@woods.net To: time-nuts@febo.com Sent: Sunday, August 19, 2012 3:38 PM Subject: Re: [time-nuts] Modern motherboard with RS232 port Converting VA to W is same as converting peak V to RMS V. ___ 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] Fun with the Z3815
On 8/11/12 4:16 AM, Azelio Boriani wrote: Very strange the inductor on the antenna cable: my Z3815A has a capacitor also because there is a different power for the antenna and I suspect that you have a short between the Furuno antenna power and the Z3815A antenna power. Think you looking at different things. There should be an inductor at the DC injection point, connecting to the signal line. And a cap as a DC block twards the receiver in-line with it. ___ 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] HP 5335 parts
Picked up a 5335A, works, but not in as good a shape as I hoped. HPIB interface board and bracket have been removed, along with both cables running to the HPIB connector board. The gate time control is intermittent. Minor, but the screen panel is cracked and the little plastic tabs damaged. If anyone has A7 HP-IB board MP27 HP-IB board support bracket W9 cable W10 cable Screen w/ plastic mounting tabs Gate POT or a board I can salvage one from Please contact me off list. This unit has the 040 front panel, so I want to repair it, but I don't want to rob parts from by no options base unit (that one is actually in current cal). Thanks ___ 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] Trimble Thunderbolt GPS Antenna
Agreed, I picked up a new in box Symmetricom 58532 this winter. I was very surprised to get a usable signal from indoors (through attic, shingles, 4 inches of ice and 2 - 3 feet of snow). From the same room, my SIRFIII based GPSes would take 5 minutes or more to warm-lock and would randomly drop. Location output was also semi-random walk over 100+ meters. Normally these little SIRFIII units are 5 seconds to warm lock and within 2 meters. Now that the roof is almost clear of snow I am looking forward to seeing how well it will do with an actual sky view. On 4/29/12 8:46 AM, Mark Spencer wrote: I've been pleased with the performance of the Symmetricom 58532. I believe it has more gain than many other antennas and my case feeds a lengthy run (maybe 80 feet or so ?) of RG58 whichin turn feeds my Thunderbolt. --- On Sun, 4/29/12, Ken Kubick kenkub...@hotmail.com wrote: From: Ken Kubick kenkub...@hotmail.com Subject: [time-nuts] Trimble Thunderbolt GPS Antenna To: Time Nuts time-nuts@febo.com Received: Sunday, April 29, 2012, 12:29 PM Hi, Time-Nuts guys I just baught a Trimble Thunderbolt on ebay. I am in need of an antenna, there are so many on ebay I am not sure which one to get. Maybe someone could point me in the right direction? Thankyou Ken Kubick kenkub...@hotmail.com ___ 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] HP 10811D question
I have a 5370B with a -60111, and a 5335 with a dead 10544. I also have a 10811D sitting on the desk. I have been through the 10811A/B manual, and what looks like an extension for the D/E and various -XXX versions. It looks to me like the D is a drop in replacement for the A, but did not see anything specific on that point. Was thinking of moving to -60111 to the 5335 and installing the 10811D in the 5370B. Is the D a drop in? ___ 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] HP 10811D question
Thanks for the cross-check (and the links)! The 5091-1639E.pdf datasheet was the piece I was missing. The only D/E docs I had found were advert and per - sub model stability specs. No pinout, voltage, schema info. On 4/28/12 4:31 AM, Azelio Boriani wrote: By checking the 10811A/B manual and the 10811D/E specifications they are perfectly equal. Pinout is the same as can be seen here http://www.qsl.net/d/dk7nt/cro/download/5091-1639E.pdf compared with www.hparchive.com/Manuals/HP-10811AB-Manual.pdf On Sat, Apr 28, 2012 at 11:19 AM, Christopher Brown cbr...@woods.netwrote: I have a 5370B with a -60111, and a 5335 with a dead 10544. I also have a 10811D sitting on the desk. I have been through the 10811A/B manual, and what looks like an extension for the D/E and various -XXX versions. It looks to me like the D is a drop in replacement for the A, but did not see anything specific on that point. Was thinking of moving to -60111 to the 5335 and installing the 10811D in the 5370B. Is the D a drop in? ___ 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.
